diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/seccomp/.gitignore | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/Makefile | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/config | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_benchmark.c | 135 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 4162 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/settings | 1 |
6 files changed, 4311 insertions, 0 deletions
diff --git a/tools/testing/selftests/seccomp/.gitignore b/tools/testing/selftests/seccomp/.gitignore new file mode 100644 index 000000000..dec678577 --- /dev/null +++ b/tools/testing/selftests/seccomp/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +seccomp_bpf +seccomp_benchmark diff --git a/tools/testing/selftests/seccomp/Makefile b/tools/testing/selftests/seccomp/Makefile new file mode 100644 index 000000000..585f7a0c1 --- /dev/null +++ b/tools/testing/selftests/seccomp/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS += -Wl,-no-as-needed -Wall -isystem ../../../../usr/include/ +LDFLAGS += -lpthread + +TEST_GEN_PROGS := seccomp_bpf seccomp_benchmark +include ../lib.mk diff --git a/tools/testing/selftests/seccomp/config b/tools/testing/selftests/seccomp/config new file mode 100644 index 000000000..ad431a517 --- /dev/null +++ b/tools/testing/selftests/seccomp/config @@ -0,0 +1,4 @@ +CONFIG_PID_NS=y +CONFIG_SECCOMP=y +CONFIG_SECCOMP_FILTER=y +CONFIG_USER_NS=y diff --git a/tools/testing/selftests/seccomp/seccomp_benchmark.c b/tools/testing/selftests/seccomp/seccomp_benchmark.c new file mode 100644 index 000000000..91f5a89ca --- /dev/null +++ b/tools/testing/selftests/seccomp/seccomp_benchmark.c @@ -0,0 +1,135 @@ +/* + * Strictly speaking, this is not a test. But it can report during test + * runs so relative performace can be measured. + */ +#define _GNU_SOURCE +#include <assert.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <linux/filter.h> +#include <linux/seccomp.h> +#include <sys/prctl.h> +#include <sys/syscall.h> +#include <sys/types.h> + +#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0])) + +unsigned long long timing(clockid_t clk_id, unsigned long long samples) +{ + struct timespec start, finish; + unsigned long long i; + pid_t pid, ret; + + pid = getpid(); + assert(clock_gettime(clk_id, &start) == 0); + for (i = 0; i < samples; i++) { + ret = syscall(__NR_getpid); + assert(pid == ret); + } + assert(clock_gettime(clk_id, &finish) == 0); + + i = finish.tv_sec - start.tv_sec; + i *= 1000000000ULL; + i += finish.tv_nsec - start.tv_nsec; + + printf("%lu.%09lu - %lu.%09lu = %llu (%.1fs)\n", + finish.tv_sec, finish.tv_nsec, + start.tv_sec, start.tv_nsec, + i, (double)i / 1000000000.0); + + return i; +} + +unsigned long long calibrate(void) +{ + struct timespec start, finish; + unsigned long long i, samples, step = 9973; + pid_t pid, ret; + int seconds = 15; + + printf("Calibrating sample size for %d seconds worth of syscalls ...\n", seconds); + + samples = 0; + pid = getpid(); + assert(clock_gettime(CLOCK_MONOTONIC, &start) == 0); + do { + for (i = 0; i < step; i++) { + ret = syscall(__NR_getpid); + assert(pid == ret); + } + assert(clock_gettime(CLOCK_MONOTONIC, &finish) == 0); + + samples += step; + i = finish.tv_sec - start.tv_sec; + i *= 1000000000ULL; + i += finish.tv_nsec - start.tv_nsec; + } while (i < 1000000000ULL); + + return samples * seconds; +} + +int main(int argc, char *argv[]) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + unsigned long long samples; + unsigned long long native, filter1, filter2; + + printf("Current BPF sysctl settings:\n"); + system("sysctl net.core.bpf_jit_enable"); + system("sysctl net.core.bpf_jit_harden"); + + if (argc > 1) + samples = strtoull(argv[1], NULL, 0); + else + samples = calibrate(); + + printf("Benchmarking %llu syscalls...\n", samples); + + /* Native call */ + native = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid native: %llu ns\n", native); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + assert(ret == 0); + + /* One filter */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + assert(ret == 0); + + filter1 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 1 filter: %llu ns\n", filter1); + + if (filter1 == native) + printf("No overhead measured!? Try running again with more samples.\n"); + + /* Two filters */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + assert(ret == 0); + + filter2 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 2 filters: %llu ns\n", filter2); + + /* Calculations */ + printf("Estimated total seccomp overhead for 1 filter: %llu ns\n", + filter1 - native); + + printf("Estimated total seccomp overhead for 2 filters: %llu ns\n", + filter2 - native); + + printf("Estimated seccomp per-filter overhead: %llu ns\n", + filter2 - filter1); + + printf("Estimated seccomp entry overhead: %llu ns\n", + filter1 - native - (filter2 - filter1)); + + return 0; +} diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c new file mode 100644 index 000000000..413a7b9f3 --- /dev/null +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -0,0 +1,4162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. + * + * Test code for seccomp bpf. + */ + +#define _GNU_SOURCE +#include <sys/types.h> + +/* + * glibc 2.26 and later have SIGSYS in siginfo_t. Before that, + * we need to use the kernel's siginfo.h file and trick glibc + * into accepting it. + */ +#if !__GLIBC_PREREQ(2, 26) +# include <asm/siginfo.h> +# define __have_siginfo_t 1 +# define __have_sigval_t 1 +# define __have_sigevent_t 1 +#endif + +#include <errno.h> +#include <linux/filter.h> +#include <sys/prctl.h> +#include <sys/ptrace.h> +#include <sys/user.h> +#include <linux/prctl.h> +#include <linux/ptrace.h> +#include <linux/seccomp.h> +#include <pthread.h> +#include <semaphore.h> +#include <signal.h> +#include <stddef.h> +#include <stdbool.h> +#include <string.h> +#include <time.h> +#include <limits.h> +#include <linux/elf.h> +#include <sys/uio.h> +#include <sys/utsname.h> +#include <sys/fcntl.h> +#include <sys/mman.h> +#include <sys/times.h> +#include <sys/socket.h> +#include <sys/ioctl.h> +#include <linux/kcmp.h> +#include <sys/resource.h> + +#include <unistd.h> +#include <sys/syscall.h> +#include <poll.h> + +#include "../kselftest_harness.h" +#include "../clone3/clone3_selftests.h" + +/* Attempt to de-conflict with the selftests tree. */ +#ifndef SKIP +#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) +#endif + +#ifndef PR_SET_PTRACER +# define PR_SET_PTRACER 0x59616d61 +#endif + +#ifndef PR_SET_NO_NEW_PRIVS +#define PR_SET_NO_NEW_PRIVS 38 +#define PR_GET_NO_NEW_PRIVS 39 +#endif + +#ifndef PR_SECCOMP_EXT +#define PR_SECCOMP_EXT 43 +#endif + +#ifndef SECCOMP_EXT_ACT +#define SECCOMP_EXT_ACT 1 +#endif + +#ifndef SECCOMP_EXT_ACT_TSYNC +#define SECCOMP_EXT_ACT_TSYNC 1 +#endif + +#ifndef SECCOMP_MODE_STRICT +#define SECCOMP_MODE_STRICT 1 +#endif + +#ifndef SECCOMP_MODE_FILTER +#define SECCOMP_MODE_FILTER 2 +#endif + +#ifndef SECCOMP_RET_ALLOW +struct seccomp_data { + int nr; + __u32 arch; + __u64 instruction_pointer; + __u64 args[6]; +}; +#endif + +#ifndef SECCOMP_RET_KILL_PROCESS +#define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */ +#define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */ +#endif +#ifndef SECCOMP_RET_KILL +#define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD +#define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ +#define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ +#define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ +#define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ +#endif +#ifndef SECCOMP_RET_LOG +#define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */ +#endif + +#ifndef __NR_seccomp +# if defined(__i386__) +# define __NR_seccomp 354 +# elif defined(__x86_64__) +# define __NR_seccomp 317 +# elif defined(__arm__) +# define __NR_seccomp 383 +# elif defined(__aarch64__) +# define __NR_seccomp 277 +# elif defined(__riscv) +# define __NR_seccomp 277 +# elif defined(__csky__) +# define __NR_seccomp 277 +# elif defined(__hppa__) +# define __NR_seccomp 338 +# elif defined(__powerpc__) +# define __NR_seccomp 358 +# elif defined(__s390__) +# define __NR_seccomp 348 +# elif defined(__xtensa__) +# define __NR_seccomp 337 +# elif defined(__sh__) +# define __NR_seccomp 372 +# else +# warning "seccomp syscall number unknown for this architecture" +# define __NR_seccomp 0xffff +# endif +#endif + +#ifndef SECCOMP_SET_MODE_STRICT +#define SECCOMP_SET_MODE_STRICT 0 +#endif + +#ifndef SECCOMP_SET_MODE_FILTER +#define SECCOMP_SET_MODE_FILTER 1 +#endif + +#ifndef SECCOMP_GET_ACTION_AVAIL +#define SECCOMP_GET_ACTION_AVAIL 2 +#endif + +#ifndef SECCOMP_GET_NOTIF_SIZES +#define SECCOMP_GET_NOTIF_SIZES 3 +#endif + +#ifndef SECCOMP_FILTER_FLAG_TSYNC +#define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0) +#endif + +#ifndef SECCOMP_FILTER_FLAG_LOG +#define SECCOMP_FILTER_FLAG_LOG (1UL << 1) +#endif + +#ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW +#define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2) +#endif + +#ifndef PTRACE_SECCOMP_GET_METADATA +#define PTRACE_SECCOMP_GET_METADATA 0x420d + +struct seccomp_metadata { + __u64 filter_off; /* Input: which filter */ + __u64 flags; /* Output: filter's flags */ +}; +#endif + +#ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER +#define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3) +#endif + +#ifndef SECCOMP_RET_USER_NOTIF +#define SECCOMP_RET_USER_NOTIF 0x7fc00000U + +#define SECCOMP_IOC_MAGIC '!' +#define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr) +#define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type) +#define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type) +#define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type) + +/* Flags for seccomp notification fd ioctl. */ +#define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif) +#define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \ + struct seccomp_notif_resp) +#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64) + +struct seccomp_notif { + __u64 id; + __u32 pid; + __u32 flags; + struct seccomp_data data; +}; + +struct seccomp_notif_resp { + __u64 id; + __s64 val; + __s32 error; + __u32 flags; +}; + +struct seccomp_notif_sizes { + __u16 seccomp_notif; + __u16 seccomp_notif_resp; + __u16 seccomp_data; +}; +#endif + +#ifndef SECCOMP_IOCTL_NOTIF_ADDFD +/* On success, the return value is the remote process's added fd number */ +#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ + struct seccomp_notif_addfd) + +/* valid flags for seccomp_notif_addfd */ +#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ + +struct seccomp_notif_addfd { + __u64 id; + __u32 flags; + __u32 srcfd; + __u32 newfd; + __u32 newfd_flags; +}; +#endif + +struct seccomp_notif_addfd_small { + __u64 id; + char weird[4]; +}; +#define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \ + SECCOMP_IOW(3, struct seccomp_notif_addfd_small) + +struct seccomp_notif_addfd_big { + union { + struct seccomp_notif_addfd addfd; + char buf[sizeof(struct seccomp_notif_addfd) + 8]; + }; +}; +#define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \ + SECCOMP_IOWR(3, struct seccomp_notif_addfd_big) + +#ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY +#define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 +#define PTRACE_EVENTMSG_SYSCALL_EXIT 2 +#endif + +#ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE +#define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001 +#endif + +#ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH +#define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4) +#endif + +#ifndef seccomp +int seccomp(unsigned int op, unsigned int flags, void *args) +{ + errno = 0; + return syscall(__NR_seccomp, op, flags, args); +} +#endif + +#if __BYTE_ORDER == __LITTLE_ENDIAN +#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) +#elif __BYTE_ORDER == __BIG_ENDIAN +#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) +#else +#error "wut? Unknown __BYTE_ORDER?!" +#endif + +#define SIBLING_EXIT_UNKILLED 0xbadbeef +#define SIBLING_EXIT_FAILURE 0xbadface +#define SIBLING_EXIT_NEWPRIVS 0xbadfeed + +static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2) +{ +#ifdef __NR_kcmp + errno = 0; + return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2); +#else + errno = ENOSYS; + return -1; +#endif +} + +/* Have TH_LOG report actual location filecmp() is used. */ +#define filecmp(pid1, pid2, fd1, fd2) ({ \ + int _ret; \ + \ + _ret = __filecmp(pid1, pid2, fd1, fd2); \ + if (_ret != 0) { \ + if (_ret < 0 && errno == ENOSYS) { \ + TH_LOG("kcmp() syscall missing (test is less accurate)");\ + _ret = 0; \ + } \ + } \ + _ret; }) + +TEST(kcmp) +{ + int ret; + + ret = __filecmp(getpid(), getpid(), 1, 1); + EXPECT_EQ(ret, 0); + if (ret != 0 && errno == ENOSYS) + SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)"); +} + +TEST(mode_strict_support) +{ + long ret; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support CONFIG_SECCOMP"); + } + syscall(__NR_exit, 0); +} + +TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) +{ + long ret; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support CONFIG_SECCOMP"); + } + syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, + NULL, NULL, NULL); + EXPECT_FALSE(true) { + TH_LOG("Unreachable!"); + } +} + +/* Note! This doesn't test no new privs behavior */ +TEST(no_new_privs_support) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + EXPECT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } +} + +/* Tests kernel support by checking for a copy_from_user() fault on NULL. */ +TEST(mode_filter_support) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EFAULT, errno) { + TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); + } +} + +TEST(mode_filter_without_nnp) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); + ASSERT_LE(0, ret) { + TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); + } + errno = 0; + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + /* Succeeds with CAP_SYS_ADMIN, fails without */ + /* TODO(wad) check caps not euid */ + if (geteuid()) { + EXPECT_EQ(-1, ret); + EXPECT_EQ(EACCES, errno); + } else { + EXPECT_EQ(0, ret); + } +} + +#define MAX_INSNS_PER_PATH 32768 + +TEST(filter_size_limits) +{ + int i; + int count = BPF_MAXINSNS + 1; + struct sock_filter allow[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter *filter; + struct sock_fprog prog = { }; + long ret; + + filter = calloc(count, sizeof(*filter)); + ASSERT_NE(NULL, filter); + + for (i = 0; i < count; i++) + filter[i] = allow[0]; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + prog.filter = filter; + prog.len = count; + + /* Too many filter instructions in a single filter. */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_NE(0, ret) { + TH_LOG("Installing %d insn filter was allowed", prog.len); + } + + /* One less is okay, though. */ + prog.len -= 1; + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Installing %d insn filter wasn't allowed", prog.len); + } +} + +TEST(filter_chain_limits) +{ + int i; + int count = BPF_MAXINSNS; + struct sock_filter allow[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter *filter; + struct sock_fprog prog = { }; + long ret; + + filter = calloc(count, sizeof(*filter)); + ASSERT_NE(NULL, filter); + + for (i = 0; i < count; i++) + filter[i] = allow[0]; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + prog.filter = filter; + prog.len = 1; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + prog.len = count; + + /* Too many total filter instructions. */ + for (i = 0; i < MAX_INSNS_PER_PATH; i++) { + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + if (ret != 0) + break; + } + ASSERT_NE(0, ret) { + TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", + i, count, i * (count + 4)); + } +} + +TEST(mode_filter_cannot_move_to_strict) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); +} + + +TEST(mode_filter_get_seccomp) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); + EXPECT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); + EXPECT_EQ(2, ret); +} + + +TEST(ALLOW_all) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); +} + +TEST(empty_prog) +{ + struct sock_filter filter[] = { + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); +} + +TEST(log_all) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + /* getppid() should succeed and be logged (no check for logging) */ + EXPECT_EQ(parent, syscall(__NR_getppid)); +} + +TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, 0x10000000U), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + EXPECT_EQ(0, syscall(__NR_getpid)) { + TH_LOG("getpid() shouldn't ever return"); + } +} + +/* return code >= 0x80000000 is unused. */ +TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, 0x90000000U), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + EXPECT_EQ(0, syscall(__NR_getpid)) { + TH_LOG("getpid() shouldn't ever return"); + } +} + +TEST_SIGNAL(KILL_all, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); +} + +TEST_SIGNAL(KILL_one, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_SIGNAL(KILL_one_arg_one, SIGSYS) +{ + void *fatal_address; + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + /* Only both with lower 32-bit for now. */ + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, + (unsigned long)&fatal_address, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + struct tms timebuf; + clock_t clock = times(&timebuf); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_LE(clock, syscall(__NR_times, &timebuf)); + /* times() should never return. */ + EXPECT_EQ(0, syscall(__NR_times, &fatal_address)); +} + +TEST_SIGNAL(KILL_one_arg_six, SIGSYS) +{ +#ifndef __NR_mmap2 + int sysno = __NR_mmap; +#else + int sysno = __NR_mmap2; +#endif + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + /* Only both with lower 32-bit for now. */ + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + int fd; + void *map1, *map2; + int page_size = sysconf(_SC_PAGESIZE); + + ASSERT_LT(0, page_size); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + fd = open("/dev/zero", O_RDONLY); + ASSERT_NE(-1, fd); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + map1 = (void *)syscall(sysno, + NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size); + EXPECT_NE(MAP_FAILED, map1); + /* mmap2() should never return. */ + map2 = (void *)syscall(sysno, + NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE); + EXPECT_EQ(MAP_FAILED, map2); + + /* The test failed, so clean up the resources. */ + munmap(map1, page_size); + munmap(map2, page_size); + close(fd); +} + +/* This is a thread task to die via seccomp filter violation. */ +void *kill_thread(void *data) +{ + bool die = (bool)data; + + if (die) { + prctl(PR_GET_SECCOMP, 0, 0, 0, 0); + return (void *)SIBLING_EXIT_FAILURE; + } + + return (void *)SIBLING_EXIT_UNKILLED; +} + +enum kill_t { + KILL_THREAD, + KILL_PROCESS, + RET_UNKNOWN +}; + +/* Prepare a thread that will kill itself or both of us. */ +void kill_thread_or_group(struct __test_metadata *_metadata, + enum kill_t kill_how) +{ + pthread_t thread; + void *status; + /* Kill only when calling __NR_prctl. */ + struct sock_filter filter_thread[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog_thread = { + .len = (unsigned short)ARRAY_SIZE(filter_thread), + .filter = filter_thread, + }; + int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAA; + struct sock_filter filter_process[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), + BPF_STMT(BPF_RET|BPF_K, kill), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog_process = { + .len = (unsigned short)ARRAY_SIZE(filter_process), + .filter = filter_process, + }; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, + kill_how == KILL_THREAD ? &prog_thread + : &prog_process)); + + /* + * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS + * flag cannot be downgraded by a new filter. + */ + if (kill_how == KILL_PROCESS) + ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread)); + + /* Start a thread that will exit immediately. */ + ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false)); + ASSERT_EQ(0, pthread_join(thread, &status)); + ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status); + + /* Start a thread that will die immediately. */ + ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true)); + ASSERT_EQ(0, pthread_join(thread, &status)); + ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status); + + /* + * If we get here, only the spawned thread died. Let the parent know + * the whole process didn't die (i.e. this thread, the spawner, + * stayed running). + */ + exit(42); +} + +TEST(KILL_thread) +{ + int status; + pid_t child_pid; + + child_pid = fork(); + ASSERT_LE(0, child_pid); + if (child_pid == 0) { + kill_thread_or_group(_metadata, KILL_THREAD); + _exit(38); + } + + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + + /* If only the thread was killed, we'll see exit 42. */ + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(42, WEXITSTATUS(status)); +} + +TEST(KILL_process) +{ + int status; + pid_t child_pid; + + child_pid = fork(); + ASSERT_LE(0, child_pid); + if (child_pid == 0) { + kill_thread_or_group(_metadata, KILL_PROCESS); + _exit(38); + } + + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + + /* If the entire process was killed, we'll see SIGSYS. */ + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_EQ(SIGSYS, WTERMSIG(status)); +} + +TEST(KILL_unknown) +{ + int status; + pid_t child_pid; + + child_pid = fork(); + ASSERT_LE(0, child_pid); + if (child_pid == 0) { + kill_thread_or_group(_metadata, RET_UNKNOWN); + _exit(38); + } + + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + + /* If the entire process was killed, we'll see SIGSYS. */ + EXPECT_TRUE(WIFSIGNALED(status)) { + TH_LOG("Unknown SECCOMP_RET is only killing the thread?"); + } + ASSERT_EQ(SIGSYS, WTERMSIG(status)); +} + +/* TODO(wad) add 64-bit versus 32-bit arg tests. */ +TEST(arg_out_of_range) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); +} + +#define ERRNO_FILTER(name, errno) \ + struct sock_filter _read_filter_##name[] = { \ + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \ + offsetof(struct seccomp_data, nr)), \ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \ + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \ + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \ + }; \ + struct sock_fprog prog_##name = { \ + .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \ + .filter = _read_filter_##name, \ + } + +/* Make sure basic errno values are correctly passed through a filter. */ +TEST(ERRNO_valid) +{ + ERRNO_FILTER(valid, E2BIG); + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(-1, read(-1, NULL, 0)); + EXPECT_EQ(E2BIG, errno); +} + +/* Make sure an errno of zero is correctly handled by the arch code. */ +TEST(ERRNO_zero) +{ + ERRNO_FILTER(zero, 0); + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* "errno" of 0 is ok. */ + EXPECT_EQ(0, read(-1, NULL, 0)); +} + +/* + * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller. + * This tests that the errno value gets capped correctly, fixed by + * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO"). + */ +TEST(ERRNO_capped) +{ + ERRNO_FILTER(capped, 4096); + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(-1, read(-1, NULL, 0)); + EXPECT_EQ(4095, errno); +} + +/* + * Filters are processed in reverse order: last applied is executed first. + * Since only the SECCOMP_RET_ACTION mask is tested for return values, the + * SECCOMP_RET_DATA mask results will follow the most recently applied + * matching filter return (and not the lowest or highest value). + */ +TEST(ERRNO_order) +{ + ERRNO_FILTER(first, 11); + ERRNO_FILTER(second, 13); + ERRNO_FILTER(third, 12); + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(-1, read(-1, NULL, 0)); + EXPECT_EQ(12, errno); +} + +FIXTURE(TRAP) { + struct sock_fprog prog; +}; + +FIXTURE_SETUP(TRAP) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + memset(&self->prog, 0, sizeof(self->prog)); + self->prog.filter = malloc(sizeof(filter)); + ASSERT_NE(NULL, self->prog.filter); + memcpy(self->prog.filter, filter, sizeof(filter)); + self->prog.len = (unsigned short)ARRAY_SIZE(filter); +} + +FIXTURE_TEARDOWN(TRAP) +{ + if (self->prog.filter) + free(self->prog.filter); +} + +TEST_F_SIGNAL(TRAP, dfl, SIGSYS) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); + ASSERT_EQ(0, ret); + syscall(__NR_getpid); +} + +/* Ensure that SIGSYS overrides SIG_IGN */ +TEST_F_SIGNAL(TRAP, ign, SIGSYS) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + signal(SIGSYS, SIG_IGN); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); + ASSERT_EQ(0, ret); + syscall(__NR_getpid); +} + +static siginfo_t TRAP_info; +static volatile int TRAP_nr; +static void TRAP_action(int nr, siginfo_t *info, void *void_context) +{ + memcpy(&TRAP_info, info, sizeof(TRAP_info)); + TRAP_nr = nr; +} + +TEST_F(TRAP, handler) +{ + int ret, test; + struct sigaction act; + sigset_t mask; + + memset(&act, 0, sizeof(act)); + sigemptyset(&mask); + sigaddset(&mask, SIGSYS); + + act.sa_sigaction = &TRAP_action; + act.sa_flags = SA_SIGINFO; + ret = sigaction(SIGSYS, &act, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("sigaction failed"); + } + ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("sigprocmask failed"); + } + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); + ASSERT_EQ(0, ret); + TRAP_nr = 0; + memset(&TRAP_info, 0, sizeof(TRAP_info)); + /* Expect the registers to be rolled back. (nr = error) may vary + * based on arch. */ + ret = syscall(__NR_getpid); + /* Silence gcc warning about volatile. */ + test = TRAP_nr; + EXPECT_EQ(SIGSYS, test); + struct local_sigsys { + void *_call_addr; /* calling user insn */ + int _syscall; /* triggering system call number */ + unsigned int _arch; /* AUDIT_ARCH_* of syscall */ + } *sigsys = (struct local_sigsys *) +#ifdef si_syscall + &(TRAP_info.si_call_addr); +#else + &TRAP_info.si_pid; +#endif + EXPECT_EQ(__NR_getpid, sigsys->_syscall); + /* Make sure arch is non-zero. */ + EXPECT_NE(0, sigsys->_arch); + EXPECT_NE(0, (unsigned long)sigsys->_call_addr); +} + +FIXTURE(precedence) { + struct sock_fprog allow; + struct sock_fprog log; + struct sock_fprog trace; + struct sock_fprog error; + struct sock_fprog trap; + struct sock_fprog kill; +}; + +FIXTURE_SETUP(precedence) +{ + struct sock_filter allow_insns[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter log_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG), + }; + struct sock_filter trace_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), + }; + struct sock_filter error_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), + }; + struct sock_filter trap_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), + }; + struct sock_filter kill_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + }; + + memset(self, 0, sizeof(*self)); +#define FILTER_ALLOC(_x) \ + self->_x.filter = malloc(sizeof(_x##_insns)); \ + ASSERT_NE(NULL, self->_x.filter); \ + memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ + self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) + FILTER_ALLOC(allow); + FILTER_ALLOC(log); + FILTER_ALLOC(trace); + FILTER_ALLOC(error); + FILTER_ALLOC(trap); + FILTER_ALLOC(kill); +} + +FIXTURE_TEARDOWN(precedence) +{ +#define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) + FILTER_FREE(allow); + FILTER_FREE(log); + FILTER_FREE(trace); + FILTER_FREE(error); + FILTER_FREE(trap); + FILTER_FREE(kill); +} + +TEST_F(precedence, allow_ok) +{ + pid_t parent, res = 0; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + res = syscall(__NR_getppid); + EXPECT_EQ(parent, res); +} + +TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) +{ + pid_t parent, res = 0; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + res = syscall(__NR_getppid); + EXPECT_EQ(parent, res); + /* getpid() should never return. */ + res = syscall(__NR_getpid); + EXPECT_EQ(0, res); +} + +TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F(precedence, errno_is_third) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F(precedence, errno_is_third_in_any_order) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F(precedence, trace_is_fourth) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* No ptracer */ + EXPECT_EQ(-1, syscall(__NR_getpid)); +} + +TEST_F(precedence, trace_is_fourth_in_any_order) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* No ptracer */ + EXPECT_EQ(-1, syscall(__NR_getpid)); +} + +TEST_F(precedence, log_is_fifth) +{ + pid_t mypid, parent; + long ret; + + mypid = getpid(); + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* Should also work just fine */ + EXPECT_EQ(mypid, syscall(__NR_getpid)); +} + +TEST_F(precedence, log_is_fifth_in_any_order) +{ + pid_t mypid, parent; + long ret; + + mypid = getpid(); + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* Should also work just fine */ + EXPECT_EQ(mypid, syscall(__NR_getpid)); +} + +#ifndef PTRACE_O_TRACESECCOMP +#define PTRACE_O_TRACESECCOMP 0x00000080 +#endif + +/* Catch the Ubuntu 12.04 value error. */ +#if PTRACE_EVENT_SECCOMP != 7 +#undef PTRACE_EVENT_SECCOMP +#endif + +#ifndef PTRACE_EVENT_SECCOMP +#define PTRACE_EVENT_SECCOMP 7 +#endif + +#define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP) +bool tracer_running; +void tracer_stop(int sig) +{ + tracer_running = false; +} + +typedef void tracer_func_t(struct __test_metadata *_metadata, + pid_t tracee, int status, void *args); + +void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, + tracer_func_t tracer_func, void *args, bool ptrace_syscall) +{ + int ret = -1; + struct sigaction action = { + .sa_handler = tracer_stop, + }; + + /* Allow external shutdown. */ + tracer_running = true; + ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); + + errno = 0; + while (ret == -1 && errno != EINVAL) + ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); + ASSERT_EQ(0, ret) { + kill(tracee, SIGKILL); + } + /* Wait for attach stop */ + wait(NULL); + + ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ? + PTRACE_O_TRACESYSGOOD : + PTRACE_O_TRACESECCOMP); + ASSERT_EQ(0, ret) { + TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); + kill(tracee, SIGKILL); + } + ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, + tracee, NULL, 0); + ASSERT_EQ(0, ret); + + /* Unblock the tracee */ + ASSERT_EQ(1, write(fd, "A", 1)); + ASSERT_EQ(0, close(fd)); + + /* Run until we're shut down. Must assert to stop execution. */ + while (tracer_running) { + int status; + + if (wait(&status) != tracee) + continue; + if (WIFSIGNALED(status) || WIFEXITED(status)) + /* Child is dead. Time to go. */ + return; + + /* Check if this is a seccomp event. */ + ASSERT_EQ(!ptrace_syscall, IS_SECCOMP_EVENT(status)); + + tracer_func(_metadata, tracee, status, args); + + ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT, + tracee, NULL, 0); + ASSERT_EQ(0, ret); + } + /* Directly report the status of our test harness results. */ + syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); +} + +/* Common tracer setup/teardown functions. */ +void cont_handler(int num) +{ } +pid_t setup_trace_fixture(struct __test_metadata *_metadata, + tracer_func_t func, void *args, bool ptrace_syscall) +{ + char sync; + int pipefd[2]; + pid_t tracer_pid; + pid_t tracee = getpid(); + + /* Setup a pipe for clean synchronization. */ + ASSERT_EQ(0, pipe(pipefd)); + + /* Fork a child which we'll promote to tracer */ + tracer_pid = fork(); + ASSERT_LE(0, tracer_pid); + signal(SIGALRM, cont_handler); + if (tracer_pid == 0) { + close(pipefd[0]); + start_tracer(_metadata, pipefd[1], tracee, func, args, + ptrace_syscall); + syscall(__NR_exit, 0); + } + close(pipefd[1]); + prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); + read(pipefd[0], &sync, 1); + close(pipefd[0]); + + return tracer_pid; +} + +void teardown_trace_fixture(struct __test_metadata *_metadata, + pid_t tracer) +{ + if (tracer) { + int status; + /* + * Extract the exit code from the other process and + * adopt it for ourselves in case its asserts failed. + */ + ASSERT_EQ(0, kill(tracer, SIGUSR1)); + ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); + if (WEXITSTATUS(status)) + _metadata->passed = 0; + } +} + +/* "poke" tracer arguments and function. */ +struct tracer_args_poke_t { + unsigned long poke_addr; +}; + +void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, + void *args) +{ + int ret; + unsigned long msg; + struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; + + ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); + EXPECT_EQ(0, ret); + /* If this fails, don't try to recover. */ + ASSERT_EQ(0x1001, msg) { + kill(tracee, SIGKILL); + } + /* + * Poke in the message. + * Registers are not touched to try to keep this relatively arch + * agnostic. + */ + ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); + EXPECT_EQ(0, ret); +} + +FIXTURE(TRACE_poke) { + struct sock_fprog prog; + pid_t tracer; + long poked; + struct tracer_args_poke_t tracer_args; +}; + +FIXTURE_SETUP(TRACE_poke) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + self->poked = 0; + memset(&self->prog, 0, sizeof(self->prog)); + self->prog.filter = malloc(sizeof(filter)); + ASSERT_NE(NULL, self->prog.filter); + memcpy(self->prog.filter, filter, sizeof(filter)); + self->prog.len = (unsigned short)ARRAY_SIZE(filter); + + /* Set up tracer args. */ + self->tracer_args.poke_addr = (unsigned long)&self->poked; + + /* Launch tracer. */ + self->tracer = setup_trace_fixture(_metadata, tracer_poke, + &self->tracer_args, false); +} + +FIXTURE_TEARDOWN(TRACE_poke) +{ + teardown_trace_fixture(_metadata, self->tracer); + if (self->prog.filter) + free(self->prog.filter); +} + +TEST_F(TRACE_poke, read_has_side_effects) +{ + ssize_t ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + EXPECT_EQ(0, self->poked); + ret = read(-1, NULL, 0); + EXPECT_EQ(-1, ret); + EXPECT_EQ(0x1001, self->poked); +} + +TEST_F(TRACE_poke, getpid_runs_normally) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + EXPECT_EQ(0, self->poked); + EXPECT_NE(0, syscall(__NR_getpid)); + EXPECT_EQ(0, self->poked); +} + +#if defined(__x86_64__) +# define ARCH_REGS struct user_regs_struct +# define SYSCALL_NUM(_regs) (_regs).orig_rax +# define SYSCALL_RET(_regs) (_regs).rax +#elif defined(__i386__) +# define ARCH_REGS struct user_regs_struct +# define SYSCALL_NUM(_regs) (_regs).orig_eax +# define SYSCALL_RET(_regs) (_regs).eax +#elif defined(__arm__) +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM(_regs) (_regs).ARM_r7 +# ifndef PTRACE_SET_SYSCALL +# define PTRACE_SET_SYSCALL 23 +# endif +# define SYSCALL_NUM_SET(_regs, _nr) \ + EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr)) +# define SYSCALL_RET(_regs) (_regs).ARM_r0 +#elif defined(__aarch64__) +# define ARCH_REGS struct user_pt_regs +# define SYSCALL_NUM(_regs) (_regs).regs[8] +# ifndef NT_ARM_SYSTEM_CALL +# define NT_ARM_SYSTEM_CALL 0x404 +# endif +# define SYSCALL_NUM_SET(_regs, _nr) \ + do { \ + struct iovec __v; \ + typeof(_nr) __nr = (_nr); \ + __v.iov_base = &__nr; \ + __v.iov_len = sizeof(__nr); \ + EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \ + NT_ARM_SYSTEM_CALL, &__v)); \ + } while (0) +# define SYSCALL_RET(_regs) (_regs).regs[0] +#elif defined(__riscv) && __riscv_xlen == 64 +# define ARCH_REGS struct user_regs_struct +# define SYSCALL_NUM(_regs) (_regs).a7 +# define SYSCALL_RET(_regs) (_regs).a0 +#elif defined(__csky__) +# define ARCH_REGS struct pt_regs +# if defined(__CSKYABIV2__) +# define SYSCALL_NUM(_regs) (_regs).regs[3] +# else +# define SYSCALL_NUM(_regs) (_regs).regs[9] +# endif +# define SYSCALL_RET(_regs) (_regs).a0 +#elif defined(__hppa__) +# define ARCH_REGS struct user_regs_struct +# define SYSCALL_NUM(_regs) (_regs).gr[20] +# define SYSCALL_RET(_regs) (_regs).gr[28] +#elif defined(__powerpc__) +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM(_regs) (_regs).gpr[0] +# define SYSCALL_RET(_regs) (_regs).gpr[3] +# define SYSCALL_RET_SET(_regs, _val) \ + do { \ + typeof(_val) _result = (_val); \ + if ((_regs.trap & 0xfff0) == 0x3000) { \ + /* \ + * scv 0 system call uses -ve result \ + * for error, so no need to adjust. \ + */ \ + SYSCALL_RET(_regs) = _result; \ + } else { \ + /* \ + * A syscall error is signaled by the \ + * CR0 SO bit and the code is stored as \ + * a positive value. \ + */ \ + if (_result < 0) { \ + SYSCALL_RET(_regs) = -_result; \ + (_regs).ccr |= 0x10000000; \ + } else { \ + SYSCALL_RET(_regs) = _result; \ + (_regs).ccr &= ~0x10000000; \ + } \ + } \ + } while (0) +# define SYSCALL_RET_SET_ON_PTRACE_EXIT +#elif defined(__s390__) +# define ARCH_REGS s390_regs +# define SYSCALL_NUM(_regs) (_regs).gprs[2] +# define SYSCALL_RET_SET(_regs, _val) \ + TH_LOG("Can't modify syscall return on this architecture") +#elif defined(__mips__) +# include <asm/unistd_nr_n32.h> +# include <asm/unistd_nr_n64.h> +# include <asm/unistd_nr_o32.h> +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM(_regs) \ + ({ \ + typeof((_regs).regs[2]) _nr; \ + if ((_regs).regs[2] == __NR_O32_Linux) \ + _nr = (_regs).regs[4]; \ + else \ + _nr = (_regs).regs[2]; \ + _nr; \ + }) +# define SYSCALL_NUM_SET(_regs, _nr) \ + do { \ + if ((_regs).regs[2] == __NR_O32_Linux) \ + (_regs).regs[4] = _nr; \ + else \ + (_regs).regs[2] = _nr; \ + } while (0) +# define SYSCALL_RET_SET(_regs, _val) \ + TH_LOG("Can't modify syscall return on this architecture") +#elif defined(__xtensa__) +# define ARCH_REGS struct user_pt_regs +# define SYSCALL_NUM(_regs) (_regs).syscall +/* + * On xtensa syscall return value is in the register + * a2 of the current window which is not fixed. + */ +#define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2] +#elif defined(__sh__) +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM(_regs) (_regs).regs[3] +# define SYSCALL_RET(_regs) (_regs).regs[0] +#else +# error "Do not know how to find your architecture's registers and syscalls" +#endif + +/* + * Most architectures can change the syscall by just updating the + * associated register. This is the default if not defined above. + */ +#ifndef SYSCALL_NUM_SET +# define SYSCALL_NUM_SET(_regs, _nr) \ + do { \ + SYSCALL_NUM(_regs) = (_nr); \ + } while (0) +#endif +/* + * Most architectures can change the syscall return value by just + * writing to the SYSCALL_RET register. This is the default if not + * defined above. If an architecture cannot set the return value + * (for example when the syscall and return value register is + * shared), report it with TH_LOG() in an arch-specific definition + * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined. + */ +#if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET) +# error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch" +#endif +#ifndef SYSCALL_RET_SET +# define SYSCALL_RET_SET(_regs, _val) \ + do { \ + SYSCALL_RET(_regs) = (_val); \ + } while (0) +#endif + +/* When the syscall return can't be changed, stub out the tests for it. */ +#ifndef SYSCALL_RET +# define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action) +#else +# define EXPECT_SYSCALL_RETURN(val, action) \ + do { \ + errno = 0; \ + if (val < 0) { \ + EXPECT_EQ(-1, action); \ + EXPECT_EQ(-(val), errno); \ + } else { \ + EXPECT_EQ(val, action); \ + } \ + } while (0) +#endif + +/* + * Some architectures (e.g. powerpc) can only set syscall + * return values on syscall exit during ptrace. + */ +const bool ptrace_entry_set_syscall_nr = true; +const bool ptrace_entry_set_syscall_ret = +#ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT + true; +#else + false; +#endif + +/* + * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for + * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux). + */ +#if defined(__x86_64__) || defined(__i386__) || defined(__mips__) +# define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs)) +# define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs)) +#else +# define ARCH_GETREGS(_regs) ({ \ + struct iovec __v; \ + __v.iov_base = &(_regs); \ + __v.iov_len = sizeof(_regs); \ + ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \ + }) +# define ARCH_SETREGS(_regs) ({ \ + struct iovec __v; \ + __v.iov_base = &(_regs); \ + __v.iov_len = sizeof(_regs); \ + ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \ + }) +#endif + +/* Architecture-specific syscall fetching routine. */ +int get_syscall(struct __test_metadata *_metadata, pid_t tracee) +{ + ARCH_REGS regs; + + EXPECT_EQ(0, ARCH_GETREGS(regs)) { + return -1; + } + + return SYSCALL_NUM(regs); +} + +/* Architecture-specific syscall changing routine. */ +void __change_syscall(struct __test_metadata *_metadata, + pid_t tracee, long *syscall, long *ret) +{ + ARCH_REGS orig, regs; + + /* Do not get/set registers if we have nothing to do. */ + if (!syscall && !ret) + return; + + EXPECT_EQ(0, ARCH_GETREGS(regs)) { + return; + } + orig = regs; + + if (syscall) + SYSCALL_NUM_SET(regs, *syscall); + + if (ret) + SYSCALL_RET_SET(regs, *ret); + + /* Flush any register changes made. */ + if (memcmp(&orig, ®s, sizeof(orig)) != 0) + EXPECT_EQ(0, ARCH_SETREGS(regs)); +} + +/* Change only syscall number. */ +void change_syscall_nr(struct __test_metadata *_metadata, + pid_t tracee, long syscall) +{ + __change_syscall(_metadata, tracee, &syscall, NULL); +} + +/* Change syscall return value (and set syscall number to -1). */ +void change_syscall_ret(struct __test_metadata *_metadata, + pid_t tracee, long ret) +{ + long syscall = -1; + + __change_syscall(_metadata, tracee, &syscall, &ret); +} + +void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee, + int status, void *args) +{ + int ret; + unsigned long msg; + + /* Make sure we got the right message. */ + ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); + EXPECT_EQ(0, ret); + + /* Validate and take action on expected syscalls. */ + switch (msg) { + case 0x1002: + /* change getpid to getppid. */ + EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee)); + change_syscall_nr(_metadata, tracee, __NR_getppid); + break; + case 0x1003: + /* skip gettid with valid return code. */ + EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee)); + change_syscall_ret(_metadata, tracee, 45000); + break; + case 0x1004: + /* skip openat with error. */ + EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee)); + change_syscall_ret(_metadata, tracee, -ESRCH); + break; + case 0x1005: + /* do nothing (allow getppid) */ + EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee)); + break; + default: + EXPECT_EQ(0, msg) { + TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); + kill(tracee, SIGKILL); + } + } + +} + +FIXTURE(TRACE_syscall) { + struct sock_fprog prog; + pid_t tracer, mytid, mypid, parent; + long syscall_nr; +}; + +void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee, + int status, void *args) +{ + int ret; + unsigned long msg; + static bool entry; + long syscall_nr_val, syscall_ret_val; + long *syscall_nr = NULL, *syscall_ret = NULL; + FIXTURE_DATA(TRACE_syscall) *self = args; + + /* + * The traditional way to tell PTRACE_SYSCALL entry/exit + * is by counting. + */ + entry = !entry; + + /* Make sure we got an appropriate message. */ + ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); + EXPECT_EQ(0, ret); + EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY + : PTRACE_EVENTMSG_SYSCALL_EXIT, msg); + + /* + * Some architectures only support setting return values during + * syscall exit under ptrace, and on exit the syscall number may + * no longer be available. Therefore, save the initial sycall + * number here, so it can be examined during both entry and exit + * phases. + */ + if (entry) + self->syscall_nr = get_syscall(_metadata, tracee); + + /* + * Depending on the architecture's syscall setting abilities, we + * pick which things to set during this phase (entry or exit). + */ + if (entry == ptrace_entry_set_syscall_nr) + syscall_nr = &syscall_nr_val; + if (entry == ptrace_entry_set_syscall_ret) + syscall_ret = &syscall_ret_val; + + /* Now handle the actual rewriting cases. */ + switch (self->syscall_nr) { + case __NR_getpid: + syscall_nr_val = __NR_getppid; + /* Never change syscall return for this case. */ + syscall_ret = NULL; + break; + case __NR_gettid: + syscall_nr_val = -1; + syscall_ret_val = 45000; + break; + case __NR_openat: + syscall_nr_val = -1; + syscall_ret_val = -ESRCH; + break; + default: + /* Unhandled, do nothing. */ + return; + } + + __change_syscall(_metadata, tracee, syscall_nr, syscall_ret); +} + +FIXTURE_VARIANT(TRACE_syscall) { + /* + * All of the SECCOMP_RET_TRACE behaviors can be tested with either + * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL. + * This indicates if we should use SECCOMP_RET_TRACE (false), or + * ptrace (true). + */ + bool use_ptrace; +}; + +FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) { + .use_ptrace = true, +}; + +FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) { + .use_ptrace = false, +}; + +FIXTURE_SETUP(TRACE_syscall) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + /* Prepare some testable syscall results. */ + self->mytid = syscall(__NR_gettid); + ASSERT_GT(self->mytid, 0); + ASSERT_NE(self->mytid, 1) { + TH_LOG("Running this test as init is not supported. :)"); + } + + self->mypid = getpid(); + ASSERT_GT(self->mypid, 0); + ASSERT_EQ(self->mytid, self->mypid); + + self->parent = getppid(); + ASSERT_GT(self->parent, 0); + ASSERT_NE(self->parent, self->mypid); + + /* Launch tracer. */ + self->tracer = setup_trace_fixture(_metadata, + variant->use_ptrace ? tracer_ptrace + : tracer_seccomp, + self, variant->use_ptrace); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + if (variant->use_ptrace) + return; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); +} + +FIXTURE_TEARDOWN(TRACE_syscall) +{ + teardown_trace_fixture(_metadata, self->tracer); +} + +TEST(negative_ENOSYS) +{ + /* + * There should be no difference between an "internal" skip + * and userspace asking for syscall "-1". + */ + errno = 0; + EXPECT_EQ(-1, syscall(-1)); + EXPECT_EQ(errno, ENOSYS); + /* And no difference for "still not valid but not -1". */ + errno = 0; + EXPECT_EQ(-1, syscall(-101)); + EXPECT_EQ(errno, ENOSYS); +} + +TEST_F(TRACE_syscall, negative_ENOSYS) +{ + negative_ENOSYS(_metadata); +} + +TEST_F(TRACE_syscall, syscall_allowed) +{ + /* getppid works as expected (no changes). */ + EXPECT_EQ(self->parent, syscall(__NR_getppid)); + EXPECT_NE(self->mypid, syscall(__NR_getppid)); +} + +TEST_F(TRACE_syscall, syscall_redirected) +{ + /* getpid has been redirected to getppid as expected. */ + EXPECT_EQ(self->parent, syscall(__NR_getpid)); + EXPECT_NE(self->mypid, syscall(__NR_getpid)); +} + +TEST_F(TRACE_syscall, syscall_errno) +{ + /* Tracer should skip the open syscall, resulting in ESRCH. */ + EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat)); +} + +TEST_F(TRACE_syscall, syscall_faked) +{ + /* Tracer skips the gettid syscall and store altered return value. */ + EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid)); +} + +TEST_F(TRACE_syscall, skip_after) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + /* Install additional "errno on getppid" filter. */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + /* Tracer will redirect getpid to getppid, and we should see EPERM. */ + errno = 0; + EXPECT_EQ(-1, syscall(__NR_getpid)); + EXPECT_EQ(EPERM, errno); +} + +TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + /* Install additional "death on getppid" filter. */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + /* Tracer will redirect getpid to getppid, and we should die. */ + EXPECT_NE(self->mypid, syscall(__NR_getpid)); +} + +TEST(seccomp_syscall) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Reject insane operation. */ + ret = seccomp(-1, 0, &prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject crazy op value!"); + } + + /* Reject strict with flags or pointer. */ + ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject mode strict with flags!"); + } + ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject mode strict with uargs!"); + } + + /* Reject insane args for filter. */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject crazy filter flags!"); + } + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); + EXPECT_EQ(EFAULT, errno) { + TH_LOG("Did not reject NULL filter!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); + EXPECT_EQ(0, errno) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", + strerror(errno)); + } +} + +TEST(seccomp_syscall_mode_lock) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + EXPECT_EQ(0, ret) { + TH_LOG("Could not install filter!"); + } + + /* Make sure neither entry point will switch to strict. */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Switched to mode strict!"); + } + + ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Switched to mode strict!"); + } +} + +/* + * Test detection of known and unknown filter flags. Userspace needs to be able + * to check if a filter flag is supported by the current kernel and a good way + * of doing that is by attempting to enter filter mode, with the flag bit in + * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates + * that the flag is valid and EINVAL indicates that the flag is invalid. + */ +TEST(detect_seccomp_filter_flags) +{ + unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC, + SECCOMP_FILTER_FLAG_LOG, + SECCOMP_FILTER_FLAG_SPEC_ALLOW, + SECCOMP_FILTER_FLAG_NEW_LISTENER, + SECCOMP_FILTER_FLAG_TSYNC_ESRCH }; + unsigned int exclusive[] = { + SECCOMP_FILTER_FLAG_TSYNC, + SECCOMP_FILTER_FLAG_NEW_LISTENER }; + unsigned int flag, all_flags, exclusive_mask; + int i; + long ret; + + /* Test detection of individual known-good filter flags */ + for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) { + int bits = 0; + + flag = flags[i]; + /* Make sure the flag is a single bit! */ + while (flag) { + if (flag & 0x1) + bits ++; + flag >>= 1; + } + ASSERT_EQ(1, bits); + flag = flags[i]; + + ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + EXPECT_EQ(-1, ret); + EXPECT_EQ(EFAULT, errno) { + TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!", + flag); + } + + all_flags |= flag; + } + + /* + * Test detection of all known-good filter flags combined. But + * for the exclusive flags we need to mask them out and try them + * individually for the "all flags" testing. + */ + exclusive_mask = 0; + for (i = 0; i < ARRAY_SIZE(exclusive); i++) + exclusive_mask |= exclusive[i]; + for (i = 0; i < ARRAY_SIZE(exclusive); i++) { + flag = all_flags & ~exclusive_mask; + flag |= exclusive[i]; + + ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EFAULT, errno) { + TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!", + flag); + } + } + + /* Test detection of an unknown filter flags, without exclusives. */ + flag = -1; + flag &= ~exclusive_mask; + ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!", + flag); + } + + /* + * Test detection of an unknown filter flag that may simply need to be + * added to this test + */ + flag = flags[ARRAY_SIZE(flags) - 1] << 1; + ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?", + flag); + } +} + +TEST(TSYNC_first) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + EXPECT_EQ(0, ret) { + TH_LOG("Could not install initial filter with TSYNC!"); + } +} + +#define TSYNC_SIBLINGS 2 +struct tsync_sibling { + pthread_t tid; + pid_t system_tid; + sem_t *started; + pthread_cond_t *cond; + pthread_mutex_t *mutex; + int diverge; + int num_waits; + struct sock_fprog *prog; + struct __test_metadata *metadata; +}; + +/* + * To avoid joining joined threads (which is not allowed by Bionic), + * make sure we both successfully join and clear the tid to skip a + * later join attempt during fixture teardown. Any remaining threads + * will be directly killed during teardown. + */ +#define PTHREAD_JOIN(tid, status) \ + do { \ + int _rc = pthread_join(tid, status); \ + if (_rc) { \ + TH_LOG("pthread_join of tid %u failed: %d\n", \ + (unsigned int)tid, _rc); \ + } else { \ + tid = 0; \ + } \ + } while (0) + +FIXTURE(TSYNC) { + struct sock_fprog root_prog, apply_prog; + struct tsync_sibling sibling[TSYNC_SIBLINGS]; + sem_t started; + pthread_cond_t cond; + pthread_mutex_t mutex; + int sibling_count; +}; + +FIXTURE_SETUP(TSYNC) +{ + struct sock_filter root_filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter apply_filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + memset(&self->root_prog, 0, sizeof(self->root_prog)); + memset(&self->apply_prog, 0, sizeof(self->apply_prog)); + memset(&self->sibling, 0, sizeof(self->sibling)); + self->root_prog.filter = malloc(sizeof(root_filter)); + ASSERT_NE(NULL, self->root_prog.filter); + memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); + self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); + + self->apply_prog.filter = malloc(sizeof(apply_filter)); + ASSERT_NE(NULL, self->apply_prog.filter); + memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); + self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); + + self->sibling_count = 0; + pthread_mutex_init(&self->mutex, NULL); + pthread_cond_init(&self->cond, NULL); + sem_init(&self->started, 0, 0); + self->sibling[0].tid = 0; + self->sibling[0].cond = &self->cond; + self->sibling[0].started = &self->started; + self->sibling[0].mutex = &self->mutex; + self->sibling[0].diverge = 0; + self->sibling[0].num_waits = 1; + self->sibling[0].prog = &self->root_prog; + self->sibling[0].metadata = _metadata; + self->sibling[1].tid = 0; + self->sibling[1].cond = &self->cond; + self->sibling[1].started = &self->started; + self->sibling[1].mutex = &self->mutex; + self->sibling[1].diverge = 0; + self->sibling[1].prog = &self->root_prog; + self->sibling[1].num_waits = 1; + self->sibling[1].metadata = _metadata; +} + +FIXTURE_TEARDOWN(TSYNC) +{ + int sib = 0; + + if (self->root_prog.filter) + free(self->root_prog.filter); + if (self->apply_prog.filter) + free(self->apply_prog.filter); + + for ( ; sib < self->sibling_count; ++sib) { + struct tsync_sibling *s = &self->sibling[sib]; + + if (!s->tid) + continue; + /* + * If a thread is still running, it may be stuck, so hit + * it over the head really hard. + */ + pthread_kill(s->tid, 9); + } + pthread_mutex_destroy(&self->mutex); + pthread_cond_destroy(&self->cond); + sem_destroy(&self->started); +} + +void *tsync_sibling(void *data) +{ + long ret = 0; + struct tsync_sibling *me = data; + + me->system_tid = syscall(__NR_gettid); + + pthread_mutex_lock(me->mutex); + if (me->diverge) { + /* Just re-apply the root prog to fork the tree */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, + me->prog, 0, 0); + } + sem_post(me->started); + /* Return outside of started so parent notices failures. */ + if (ret) { + pthread_mutex_unlock(me->mutex); + return (void *)SIBLING_EXIT_FAILURE; + } + do { + pthread_cond_wait(me->cond, me->mutex); + me->num_waits = me->num_waits - 1; + } while (me->num_waits); + pthread_mutex_unlock(me->mutex); + + ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); + if (!ret) + return (void *)SIBLING_EXIT_NEWPRIVS; + read(-1, NULL, 0); + return (void *)SIBLING_EXIT_UNKILLED; +} + +void tsync_start_sibling(struct tsync_sibling *sibling) +{ + pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); +} + +TEST_F(TSYNC, siblings_fail_prctl) +{ + long ret; + void *status; + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check prctl failure detection by requesting sib 0 diverge. */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_EQ(0, ret) { + TH_LOG("setting filter failed"); + } + + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + /* Signal the threads to clean up*/ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure diverging sibling failed to call prctl. */ + PTHREAD_JOIN(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); + PTHREAD_JOIN(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_ancestor) +{ + long ret; + void *status; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Could install filter on all threads!"); + } + /* Tell the siblings to test the policy */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + /* Ensure they are both killed and don't exit cleanly. */ + PTHREAD_JOIN(self->sibling[0].tid, &status); + EXPECT_EQ(0x0, (long)status); + PTHREAD_JOIN(self->sibling[1].tid, &status); + EXPECT_EQ(0x0, (long)status); +} + +TEST_F(TSYNC, two_sibling_want_nnp) +{ + void *status; + + /* start siblings before any prctl() operations */ + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + /* Tell the siblings to test no policy */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both upset about lacking nnp. */ + PTHREAD_JOIN(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); + PTHREAD_JOIN(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_no_filter) +{ + long ret; + void *status; + + /* start siblings before any prctl() operations */ + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &self->apply_prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_EQ(0, ret) { + TH_LOG("Could install filter on all threads!"); + } + + /* Tell the siblings to test the policy */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both killed and don't exit cleanly. */ + PTHREAD_JOIN(self->sibling[0].tid, &status); + EXPECT_EQ(0x0, (long)status); + PTHREAD_JOIN(self->sibling[1].tid, &status); + EXPECT_EQ(0x0, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_one_divergence) +{ + long ret; + void *status; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &self->apply_prog); + ASSERT_EQ(self->sibling[0].system_tid, ret) { + TH_LOG("Did not fail on diverged sibling."); + } + + /* Wake the threads */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both unkilled. */ + PTHREAD_JOIN(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); + PTHREAD_JOIN(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err) +{ + long ret, flags; + void *status; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + flags = SECCOMP_FILTER_FLAG_TSYNC | \ + SECCOMP_FILTER_FLAG_TSYNC_ESRCH; + ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog); + ASSERT_EQ(ESRCH, errno) { + TH_LOG("Did not return ESRCH for diverged sibling."); + } + ASSERT_EQ(-1, ret) { + TH_LOG("Did not fail on diverged sibling."); + } + + /* Wake the threads */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both unkilled. */ + PTHREAD_JOIN(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); + PTHREAD_JOIN(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); +} + +TEST_F(TSYNC, two_siblings_not_under_filter) +{ + long ret, sib; + void *status; + struct timespec delay = { .tv_nsec = 100000000 }; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* + * Sibling 0 will have its own seccomp policy + * and Sibling 1 will not be under seccomp at + * all. Sibling 1 will enter seccomp and 0 + * will cause failure. + */ + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &self->apply_prog); + ASSERT_EQ(ret, self->sibling[0].system_tid) { + TH_LOG("Did not fail on diverged sibling."); + } + sib = 1; + if (ret == self->sibling[0].system_tid) + sib = 0; + + pthread_mutex_lock(&self->mutex); + + /* Increment the other siblings num_waits so we can clean up + * the one we just saw. + */ + self->sibling[!sib].num_waits += 1; + + /* Signal the thread to clean up*/ + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + PTHREAD_JOIN(self->sibling[sib].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); + /* Poll for actual task death. pthread_join doesn't guarantee it. */ + while (!kill(self->sibling[sib].system_tid, 0)) + nanosleep(&delay, NULL); + /* Switch to the remaining sibling */ + sib = !sib; + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Expected the remaining sibling to sync"); + }; + + pthread_mutex_lock(&self->mutex); + + /* If remaining sibling didn't have a chance to wake up during + * the first broadcast, manually reduce the num_waits now. + */ + if (self->sibling[sib].num_waits > 1) + self->sibling[sib].num_waits = 1; + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + PTHREAD_JOIN(self->sibling[sib].tid, &status); + EXPECT_EQ(0, (long)status); + /* Poll for actual task death. pthread_join doesn't guarantee it. */ + while (!kill(self->sibling[sib].system_tid, 0)) + nanosleep(&delay, NULL); + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret); /* just us chickens */ +} + +/* Make sure restarted syscalls are seen directly as "restart_syscall". */ +TEST(syscall_restart) +{ + long ret; + unsigned long msg; + pid_t child_pid; + int pipefd[2]; + int status; + siginfo_t info = { }; + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + +#ifdef __NR_sigreturn + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0), +#endif + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), + + /* Allow __NR_write for easy logging. */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + /* The nanosleep jump target. */ + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), + /* The restart_syscall jump target. */ + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; +#if defined(__arm__) + struct utsname utsbuf; +#endif + + ASSERT_EQ(0, pipe(pipefd)); + + child_pid = fork(); + ASSERT_LE(0, child_pid); + if (child_pid == 0) { + /* Child uses EXPECT not ASSERT to deliver status correctly. */ + char buf = ' '; + struct timespec timeout = { }; + + /* Attach parent as tracer and stop. */ + EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); + EXPECT_EQ(0, raise(SIGSTOP)); + + EXPECT_EQ(0, close(pipefd[1])); + + EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + EXPECT_EQ(0, ret) { + TH_LOG("Failed to install filter!"); + } + + EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { + TH_LOG("Failed to read() sync from parent"); + } + EXPECT_EQ('.', buf) { + TH_LOG("Failed to get sync data from read()"); + } + + /* Start nanosleep to be interrupted. */ + timeout.tv_sec = 1; + errno = 0; + EXPECT_EQ(0, nanosleep(&timeout, NULL)) { + TH_LOG("Call to nanosleep() failed (errno %d)", errno); + } + + /* Read final sync from parent. */ + EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { + TH_LOG("Failed final read() from parent"); + } + EXPECT_EQ('!', buf) { + TH_LOG("Failed to get final data from read()"); + } + + /* Directly report the status of our test harness results. */ + syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS + : EXIT_FAILURE); + } + EXPECT_EQ(0, close(pipefd[0])); + + /* Attach to child, setup options, and release. */ + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, + PTRACE_O_TRACESECCOMP)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(1, write(pipefd[1], ".", 1)); + + /* Wait for nanosleep() to start. */ + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); + ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); + ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); + ASSERT_EQ(0x100, msg); + ret = get_syscall(_metadata, child_pid); + EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep); + + /* Might as well check siginfo for sanity while we're here. */ + ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); + ASSERT_EQ(SIGTRAP, info.si_signo); + ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); + EXPECT_EQ(0, info.si_errno); + EXPECT_EQ(getuid(), info.si_uid); + /* Verify signal delivery came from child (seccomp-triggered). */ + EXPECT_EQ(child_pid, info.si_pid); + + /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */ + ASSERT_EQ(0, kill(child_pid, SIGSTOP)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); + ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); + /* + * There is no siginfo on SIGSTOP any more, so we can't verify + * signal delivery came from parent now (getpid() == info.si_pid). + * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com + * At least verify the SIGSTOP via PTRACE_GETSIGINFO. + */ + EXPECT_EQ(SIGSTOP, info.si_signo); + + /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ + ASSERT_EQ(0, kill(child_pid, SIGCONT)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGCONT, WSTOPSIG(status)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + + /* Wait for restart_syscall() to start. */ + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); + ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); + ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); + + ASSERT_EQ(0x200, msg); + ret = get_syscall(_metadata, child_pid); +#if defined(__arm__) + /* + * FIXME: + * - native ARM registers do NOT expose true syscall. + * - compat ARM registers on ARM64 DO expose true syscall. + */ + ASSERT_EQ(0, uname(&utsbuf)); + if (strncmp(utsbuf.machine, "arm", 3) == 0) { + EXPECT_EQ(__NR_nanosleep, ret); + } else +#endif + { + EXPECT_EQ(__NR_restart_syscall, ret); + } + + /* Write again to end test. */ + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(1, write(pipefd[1], "!", 1)); + EXPECT_EQ(0, close(pipefd[1])); + + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + if (WIFSIGNALED(status) || WEXITSTATUS(status)) + _metadata->passed = 0; +} + +TEST_SIGNAL(filter_flag_log, SIGSYS) +{ + struct sock_filter allow_filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter kill_filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog allow_prog = { + .len = (unsigned short)ARRAY_SIZE(allow_filter), + .filter = allow_filter, + }; + struct sock_fprog kill_prog = { + .len = (unsigned short)ARRAY_SIZE(kill_filter), + .filter = kill_filter, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */ + ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG, + &allow_prog); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + EXPECT_NE(0, ret) { + TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!"); + } + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!"); + } + + /* Verify that a simple, permissive filter can be added with no flags */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog); + EXPECT_EQ(0, ret); + + /* See if the same filter can be added with the FILTER_FLAG_LOG flag */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, + &allow_prog); + ASSERT_NE(EINVAL, errno) { + TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!"); + } + EXPECT_EQ(0, ret); + + /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG, + &kill_prog); + EXPECT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST(get_action_avail) +{ + __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP, + SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE, + SECCOMP_RET_LOG, SECCOMP_RET_ALLOW }; + __u32 unknown_action = 0x10000000U; + int i; + long ret; + + ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]); + ASSERT_NE(ENOSYS, errno) { + TH_LOG("Kernel does not support seccomp syscall!"); + } + ASSERT_NE(EINVAL, errno) { + TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!"); + } + EXPECT_EQ(ret, 0); + + for (i = 0; i < ARRAY_SIZE(actions); i++) { + ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]); + EXPECT_EQ(ret, 0) { + TH_LOG("Expected action (0x%X) not available!", + actions[i]); + } + } + + /* Check that an unknown action is handled properly (EOPNOTSUPP) */ + ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action); + EXPECT_EQ(ret, -1); + EXPECT_EQ(errno, EOPNOTSUPP); +} + +TEST(get_metadata) +{ + pid_t pid; + int pipefd[2]; + char buf; + struct seccomp_metadata md; + long ret; + + /* Only real root can get metadata. */ + if (geteuid()) { + SKIP(return, "get_metadata requires real root"); + return; + } + + ASSERT_EQ(0, pipe(pipefd)); + + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) { + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + /* one with log, one without */ + EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, + SECCOMP_FILTER_FLAG_LOG, &prog)); + EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog)); + + EXPECT_EQ(0, close(pipefd[0])); + ASSERT_EQ(1, write(pipefd[1], "1", 1)); + ASSERT_EQ(0, close(pipefd[1])); + + while (1) + sleep(100); + } + + ASSERT_EQ(0, close(pipefd[1])); + ASSERT_EQ(1, read(pipefd[0], &buf, 1)); + + ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid)); + ASSERT_EQ(pid, waitpid(pid, NULL, 0)); + + /* Past here must not use ASSERT or child process is never killed. */ + + md.filter_off = 0; + errno = 0; + ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); + EXPECT_EQ(sizeof(md), ret) { + if (errno == EINVAL) + SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)"); + } + + EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG); + EXPECT_EQ(md.filter_off, 0); + + md.filter_off = 1; + ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); + EXPECT_EQ(sizeof(md), ret); + EXPECT_EQ(md.flags, 0); + EXPECT_EQ(md.filter_off, 1); + +skip: + ASSERT_EQ(0, kill(pid, SIGKILL)); +} + +static int user_notif_syscall(int nr, unsigned int flags) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog); +} + +#define USER_NOTIF_MAGIC INT_MAX +TEST(user_notification_basic) +{ + pid_t pid; + long ret; + int status, listener; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + struct pollfd pollfd; + + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + pid = fork(); + ASSERT_GE(pid, 0); + + /* Check that we get -ENOSYS with no listener attached */ + if (pid == 0) { + if (user_notif_syscall(__NR_getppid, 0) < 0) + exit(1); + ret = syscall(__NR_getppid); + exit(ret >= 0 || errno != ENOSYS); + } + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + /* Add some no-op filters for grins. */ + EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); + EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); + EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); + EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + /* Installing a second listener in the chain should EBUSY */ + EXPECT_EQ(user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER), + -1); + EXPECT_EQ(errno, EBUSY); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + ret = syscall(__NR_getppid); + exit(ret != USER_NOTIF_MAGIC); + } + + pollfd.fd = listener; + pollfd.events = POLLIN | POLLOUT; + + EXPECT_GT(poll(&pollfd, 1, -1), 0); + EXPECT_EQ(pollfd.revents, POLLIN); + + /* Test that we can't pass garbage to the kernel. */ + memset(&req, 0, sizeof(req)); + req.pid = -1; + errno = 0; + ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); + + if (ret) { + req.pid = 0; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + } + + pollfd.fd = listener; + pollfd.events = POLLIN | POLLOUT; + + EXPECT_GT(poll(&pollfd, 1, -1), 0); + EXPECT_EQ(pollfd.revents, POLLOUT); + + EXPECT_EQ(req.data.nr, __NR_getppid); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + /* check that we make sure flags == 0 */ + resp.flags = 1; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); + EXPECT_EQ(errno, EINVAL); + + resp.flags = 0; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +TEST(user_notification_with_tsync) +{ + int ret; + unsigned int flags; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* these were exclusive */ + flags = SECCOMP_FILTER_FLAG_NEW_LISTENER | + SECCOMP_FILTER_FLAG_TSYNC; + ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags)); + ASSERT_EQ(EINVAL, errno); + + /* but now they're not */ + flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH; + ret = user_notif_syscall(__NR_getppid, flags); + close(ret); + ASSERT_LE(0, ret); +} + +TEST(user_notification_kill_in_middle) +{ + pid_t pid; + long ret; + int listener; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + /* + * Check that nothing bad happens when we kill the task in the middle + * of a syscall. + */ + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + ret = syscall(__NR_getppid); + exit(ret != USER_NOTIF_MAGIC); + } + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0); + + EXPECT_EQ(kill(pid, SIGKILL), 0); + EXPECT_EQ(waitpid(pid, NULL, 0), pid); + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1); + + resp.id = req.id; + ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp); + EXPECT_EQ(ret, -1); + EXPECT_EQ(errno, ENOENT); +} + +static int handled = -1; + +static void signal_handler(int signal) +{ + if (write(handled, "c", 1) != 1) + perror("write from signal"); +} + +TEST(user_notification_signal) +{ + pid_t pid; + long ret; + int status, listener, sk_pair[2]; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + char c; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); + + listener = user_notif_syscall(__NR_gettid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + close(sk_pair[0]); + handled = sk_pair[1]; + if (signal(SIGUSR1, signal_handler) == SIG_ERR) { + perror("signal"); + exit(1); + } + /* + * ERESTARTSYS behavior is a bit hard to test, because we need + * to rely on a signal that has not yet been handled. Let's at + * least check that the error code gets propagated through, and + * hope that it doesn't break when there is actually a signal :) + */ + ret = syscall(__NR_gettid); + exit(!(ret == -1 && errno == 512)); + } + + close(sk_pair[1]); + + memset(&req, 0, sizeof(req)); + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + EXPECT_EQ(kill(pid, SIGUSR1), 0); + + /* + * Make sure the signal really is delivered, which means we're not + * stuck in the user notification code any more and the notification + * should be dead. + */ + EXPECT_EQ(read(sk_pair[0], &c, 1), 1); + + resp.id = req.id; + resp.error = -EPERM; + resp.val = 0; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); + EXPECT_EQ(errno, ENOENT); + + memset(&req, 0, sizeof(req)); + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + resp.id = req.id; + resp.error = -512; /* -ERESTARTSYS */ + resp.val = 0; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +TEST(user_notification_closed_listener) +{ + pid_t pid; + long ret; + int status, listener; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + /* + * Check that we get an ENOSYS when the listener is closed. + */ + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) { + close(listener); + ret = syscall(__NR_getppid); + exit(ret != -1 && errno != ENOSYS); + } + + close(listener); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +/* + * Check that a pid in a child namespace still shows up as valid in ours. + */ +TEST(user_notification_child_pid_ns) +{ + pid_t pid; + int status, listener; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + + ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) { + if (errno == EINVAL) + SKIP(return, "kernel missing CLONE_NEWUSER support"); + }; + + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + EXPECT_EQ(req.pid, pid); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + close(listener); +} + +/* + * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e. + * invalid. + */ +TEST(user_notification_sibling_pid_ns) +{ + pid_t pid, pid2; + int status, listener; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + + ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + ASSERT_EQ(unshare(CLONE_NEWPID), 0); + + pid2 = fork(); + ASSERT_GE(pid2, 0); + + if (pid2 == 0) + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + + EXPECT_EQ(waitpid(pid2, &status, 0), pid2); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + exit(WEXITSTATUS(status)); + } + + /* Create the sibling ns, and sibling in it. */ + ASSERT_EQ(unshare(CLONE_NEWPID), 0) { + if (errno == EPERM) + SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); + } + ASSERT_EQ(errno, 0); + + pid2 = fork(); + ASSERT_GE(pid2, 0); + + if (pid2 == 0) { + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + /* + * The pid should be 0, i.e. the task is in some namespace that + * we can't "see". + */ + EXPECT_EQ(req.pid, 0); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + exit(0); + } + + close(listener); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + EXPECT_EQ(waitpid(pid2, &status, 0), pid2); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +TEST(user_notification_fault_recv) +{ + pid_t pid; + int status, listener; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + + ASSERT_EQ(unshare(CLONE_NEWUSER), 0); + + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + + /* Do a bad recv() */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1); + EXPECT_EQ(errno, EFAULT); + + /* We should still be able to receive this notification, though. */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + EXPECT_EQ(req.pid, pid); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +TEST(seccomp_get_notif_sizes) +{ + struct seccomp_notif_sizes sizes; + + ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0); + EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif)); + EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp)); +} + +TEST(user_notification_continue) +{ + pid_t pid; + long ret; + int status, listener; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + struct pollfd pollfd; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + int dup_fd, pipe_fds[2]; + pid_t self; + + ASSERT_GE(pipe(pipe_fds), 0); + + dup_fd = dup(pipe_fds[0]); + ASSERT_GE(dup_fd, 0); + EXPECT_NE(pipe_fds[0], dup_fd); + + self = getpid(); + ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0); + exit(0); + } + + pollfd.fd = listener; + pollfd.events = POLLIN | POLLOUT; + + EXPECT_GT(poll(&pollfd, 1, -1), 0); + EXPECT_EQ(pollfd.revents, POLLIN); + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + pollfd.fd = listener; + pollfd.events = POLLIN | POLLOUT; + + EXPECT_GT(poll(&pollfd, 1, -1), 0); + EXPECT_EQ(pollfd.revents, POLLOUT); + + EXPECT_EQ(req.data.nr, __NR_dup); + + resp.id = req.id; + resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE; + + /* + * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other + * args be set to 0. + */ + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); + EXPECT_EQ(errno, EINVAL); + + resp.error = USER_NOTIF_MAGIC; + resp.val = 0; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1); + EXPECT_EQ(errno, EINVAL); + + resp.error = 0; + resp.val = 0; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) { + if (errno == EINVAL) + SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE"); + } + +skip: + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)) { + if (WEXITSTATUS(status) == 2) { + SKIP(return, "Kernel does not support kcmp() syscall"); + return; + } + } +} + +TEST(user_notification_filter_empty) +{ + pid_t pid; + long ret; + int status; + struct pollfd pollfd; + struct __clone_args args = { + .flags = CLONE_FILES, + .exit_signal = SIGCHLD, + }; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + pid = sys_clone3(&args, sizeof(args)); + ASSERT_GE(pid, 0); + + if (pid == 0) { + int listener; + + listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER); + if (listener < 0) + _exit(EXIT_FAILURE); + + if (dup2(listener, 200) != 200) + _exit(EXIT_FAILURE); + + close(listener); + + _exit(EXIT_SUCCESS); + } + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + /* + * The seccomp filter has become unused so we should be notified once + * the kernel gets around to cleaning up task struct. + */ + pollfd.fd = 200; + pollfd.events = POLLHUP; + + EXPECT_GT(poll(&pollfd, 1, 2000), 0); + EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); +} + +static void *do_thread(void *data) +{ + return NULL; +} + +TEST(user_notification_filter_empty_threaded) +{ + pid_t pid; + long ret; + int status; + struct pollfd pollfd; + struct __clone_args args = { + .flags = CLONE_FILES, + .exit_signal = SIGCHLD, + }; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + pid = sys_clone3(&args, sizeof(args)); + ASSERT_GE(pid, 0); + + if (pid == 0) { + pid_t pid1, pid2; + int listener, status; + pthread_t thread; + + listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); + if (listener < 0) + _exit(EXIT_FAILURE); + + if (dup2(listener, 200) != 200) + _exit(EXIT_FAILURE); + + close(listener); + + pid1 = fork(); + if (pid1 < 0) + _exit(EXIT_FAILURE); + + if (pid1 == 0) + _exit(EXIT_SUCCESS); + + pid2 = fork(); + if (pid2 < 0) + _exit(EXIT_FAILURE); + + if (pid2 == 0) + _exit(EXIT_SUCCESS); + + if (pthread_create(&thread, NULL, do_thread, NULL) || + pthread_join(thread, NULL)) + _exit(EXIT_FAILURE); + + if (pthread_create(&thread, NULL, do_thread, NULL) || + pthread_join(thread, NULL)) + _exit(EXIT_FAILURE); + + if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) || + WEXITSTATUS(status)) + _exit(EXIT_FAILURE); + + if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) || + WEXITSTATUS(status)) + _exit(EXIT_FAILURE); + + exit(EXIT_SUCCESS); + } + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + /* + * The seccomp filter has become unused so we should be notified once + * the kernel gets around to cleaning up task struct. + */ + pollfd.fd = 200; + pollfd.events = POLLHUP; + + EXPECT_GT(poll(&pollfd, 1, 2000), 0); + EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); +} + +TEST(user_notification_addfd) +{ + pid_t pid; + long ret; + int status, listener, memfd, fd; + struct seccomp_notif_addfd addfd = {}; + struct seccomp_notif_addfd_small small = {}; + struct seccomp_notif_addfd_big big = {}; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + /* 100 ms */ + struct timespec delay = { .tv_nsec = 100000000 }; + + memfd = memfd_create("test", 0); + ASSERT_GE(memfd, 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) + exit(1); + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + } + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + addfd.srcfd = memfd; + addfd.newfd = 0; + addfd.id = req.id; + addfd.flags = 0x0; + + /* Verify bad newfd_flags cannot be set */ + addfd.newfd_flags = ~O_CLOEXEC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.newfd_flags = O_CLOEXEC; + + /* Verify bad flags cannot be set */ + addfd.flags = 0xff; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.flags = 0; + + /* Verify that remote_fd cannot be set without setting flags */ + addfd.newfd = 1; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.newfd = 0; + + /* Verify small size cannot be set */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1); + EXPECT_EQ(errno, EINVAL); + + /* Verify we can't send bits filled in unknown buffer area */ + memset(&big, 0xAA, sizeof(big)); + big.addfd = addfd; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1); + EXPECT_EQ(errno, E2BIG); + + + /* Verify we can set an arbitrary remote fd */ + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + /* + * The child has fds 0(stdin), 1(stdout), 2(stderr), 3(memfd), + * 4(listener), so the newly allocated fd should be 5. + */ + EXPECT_EQ(fd, 5); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* Verify we can set an arbitrary remote fd with large size */ + memset(&big, 0x0, sizeof(big)); + big.addfd = addfd; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); + EXPECT_EQ(fd, 6); + + /* Verify we can set a specific remote fd */ + addfd.newfd = 42; + addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + EXPECT_EQ(fd, 42); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* Resume syscall */ + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* + * This sets the ID of the ADD FD to the last request plus 1. The + * notification ID increments 1 per notification. + */ + addfd.id = req.id + 1; + + /* This spins until the underlying notification is generated */ + while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && + errno != -EINPROGRESS) + nanosleep(&delay, NULL); + + memset(&req, 0, sizeof(req)); + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + ASSERT_EQ(addfd.id, req.id); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* Wait for child to finish. */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + close(memfd); +} + +TEST(user_notification_addfd_rlimit) +{ + pid_t pid; + long ret; + int status, listener, memfd; + struct seccomp_notif_addfd addfd = {}; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + const struct rlimit lim = { + .rlim_cur = 0, + .rlim_max = 0, + }; + + memfd = memfd_create("test", 0); + ASSERT_GE(memfd, 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0); + + addfd.srcfd = memfd; + addfd.newfd_flags = O_CLOEXEC; + addfd.newfd = 0; + addfd.id = req.id; + addfd.flags = 0; + + /* Should probably spot check /proc/sys/fs/file-nr */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EMFILE); + + addfd.newfd = 100; + addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EBADF); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* Wait for child to finish. */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + close(memfd); +} + +/* + * TODO: + * - expand NNP testing + * - better arch-specific TRACE and TRAP handlers. + * - endianness checking when appropriate + * - 64-bit arg prodding + * - arch value testing (x86 modes especially) + * - verify that FILTER_FLAG_LOG filters generate log messages + * - verify that RET_LOG generates log messages + */ + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/seccomp/settings b/tools/testing/selftests/seccomp/settings new file mode 100644 index 000000000..ba4d85f74 --- /dev/null +++ b/tools/testing/selftests/seccomp/settings @@ -0,0 +1 @@ +timeout=90 |