diff options
Diffstat (limited to '')
| -rw-r--r-- | src/exec_ptrace.h | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/src/exec_ptrace.h b/src/exec_ptrace.h new file mode 100644 index 0000000..f75f2e5 --- /dev/null +++ b/src/exec_ptrace.h @@ -0,0 +1,532 @@ +/* + * Copyright (c) 2022 Todd C. Miller <Todd.Miller@sudo.ws> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef SUDO_EXEC_PTRACE_H +#define SUDO_EXEC_PTRACE_H + +#include <sys/prctl.h> +#include <sys/ptrace.h> +#include <sys/user.h> +#include <asm/unistd.h> +#include <linux/audit.h> +#include <linux/ptrace.h> +#include <linux/seccomp.h> +#include <linux/filter.h> + +/* Older kernel headers may be missing some EM_* defines in linux/elf.h. */ +#include <elf.h> + +/* Older systems may not support execveat(2). */ +#ifndef __NR_execveat +# define __NR_execveat -1 +#endif + +/* In case userland elf.h doesn't define NT_ARM_SYSTEM_CALL. */ +#if defined(__aarch64__) && !defined(NT_ARM_SYSTEM_CALL) +# define NT_ARM_SYSTEM_CALL 0x404 +#endif + +/* In case userland doesn't define __X32_SYSCALL_BIT. */ +#if defined(__x86_64__) && !defined(__X32_SYSCALL_BIT) +# define __X32_SYSCALL_BIT 0x40000000 +#endif + +#ifdef __mips__ +# ifndef __NR_O32_Linux +# define __NR_O32_Linux 4000 +# endif +# ifndef __NR_N32_Linux +# define __NR_N32_Linux 6000 +# endif +#endif + +/* Align address to a (compat) word boundary. */ +#define WORDALIGN(_a, _r) \ + (((_a) + ((unsigned long)(_r).wordsize - 1UL)) & ~((unsigned long)(_r).wordsize - 1UL)) + +/* Align pointer to a native word boundary. */ +#define LONGALIGN(_p) \ + (((unsigned long)(_p) + (sizeof(unsigned long) - 1UL)) & ~(sizeof(unsigned long) - 1UL)) + +/* + * See syscall(2) for a list of registers used in system calls. + * For example code, see tools/testing/selftests/seccomp/seccomp_bpf.c + * + * The structs and registers vary among the different platforms. + * We define user_regs_struct as the struct to use for gettings + * and setting the general registers and define accessor + * macros to get/set the individual struct members. + * + * The value of SECCOMP_AUDIT_ARCH is used when matching the architecture + * in the seccomp(2) filter. + */ +#if defined(__x86_64__) +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_X86_64 +# ifndef __ILP32__ +# define X32_execve __X32_SYSCALL_BIT + 520 +# define X32_execveat __X32_SYSCALL_BIT + 545 +# endif +# define sudo_pt_regs struct user_regs_struct +# define reg_syscall(x) (x).orig_rax +# define reg_retval(x) (x).rax +# define reg_sp(x) (x).rsp +# define reg_arg1(x) (x).rdi +# define reg_arg2(x) (x).rsi +# define reg_arg3(x) (x).rdx +# define reg_arg4(x) (x).r10 +#elif defined(__aarch64__) +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_AARCH64 +# define sudo_pt_regs struct user_pt_regs +# define reg_syscall(x) (x).regs[8] /* w8 */ +# define reg_retval(x) (x).regs[0] /* x0 */ +# define reg_sp(x) (x).sp /* sp */ +# define reg_arg1(x) (x).regs[0] /* x0 */ +# define reg_arg2(x) (x).regs[1] /* x1 */ +# define reg_arg3(x) (x).regs[2] /* x2 */ +# define reg_arg4(x) (x).regs[3] /* x3 */ +# define reg_set_syscall(_r, _nr) do { \ + struct iovec _iov; \ + long _syscallno = (_nr); \ + _iov.iov_base = &_syscallno; \ + _iov.iov_len = sizeof(_syscallno); \ + ptrace(PTRACE_SETREGSET, pid, NT_ARM_SYSTEM_CALL, &_iov); \ +} while (0) +#elif defined(__arm__) +/* Note: assumes arm EABI, not OABI */ +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARM +# define sudo_pt_regs struct pt_regs +# define reg_syscall(x) (x).ARM_r7 +# define reg_retval(x) (x).ARM_r0 +# define reg_sp(x) (x).ARM_sp +# define reg_arg1(x) (x).ARM_r0 +# define reg_arg2(x) (x).ARM_r1 +# define reg_arg3(x) (x).ARM_r2 +# define reg_arg4(x) (x).ARM_r3 +# define reg_set_syscall(_r, _nr) do { \ + ptrace(PTRACE_SET_SYSCALL, pid, NULL, _nr); \ +} while (0) +#elif defined (__hppa__) +/* Untested (should also support hppa64) */ +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PARISC +# define sudo_pt_regs struct user_regs_struct +# define reg_syscall(x) (x).gr[20] /* r20 */ +# define reg_retval(x) (x).gr[28] /* r28 */ +# define reg_sp(x) (x).gr[30] /* r30 */ +# define reg_arg1(x) (x).gr[26] /* r26 */ +# define reg_arg2(x) (x).gr[25] /* r25 */ +# define reg_arg3(x) (x).gr[24] /* r24 */ +# define reg_arg4(x) (x).gr[23] /* r23 */ +#elif defined(__i386__) +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_I386 +# define sudo_pt_regs struct user_regs_struct +# define reg_syscall(x) (x).orig_eax +# define reg_retval(x) (x).eax +# define reg_sp(x) (x).esp +# define reg_arg1(x) (x).ebx +# define reg_arg2(x) (x).ecx +# define reg_arg3(x) (x).edx +# define reg_arg4(x) (x).esi +#elif defined(__mips__) +# if _MIPS_SIM == _MIPS_SIM_ABI32 +# /* Linux o32 style syscalls, 4000-4999. */ +# if BYTE_ORDER == LITTLE_ENDIAN +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL +# else +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS +# endif +# elif _MIPS_SIM == _MIPS_SIM_ABI64 +# /* Linux 64-bit syscalls, 5000-5999. */ +# if BYTE_ORDER == LITTLE_ENDIAN +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL64 +# else +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS64 +# endif +# elif _MIPS_SIM == _MIPS_SIM_NABI32 +# /* Linux N32 syscalls, 6000-6999. */ +# if BYTE_ORDER == LITTLE_ENDIAN +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL64N32 +# else +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS64N32 +# endif +# else +# error "Unsupported MIPS ABI" +# endif +/* + * If called via syscall(__NR_###), v0 holds __NR_O32_Linux and the real + * syscall is in the first arg (a0). The actual args are shifted by one. + * MIPS does not support setting the syscall return value via ptrace. + */ +# define sudo_pt_regs struct pt_regs +# define reg_syscall(_r) ({ \ + __u64 _nr; \ + if ((_r).regs[2] == __NR_O32_Linux) \ + _nr = (_r).regs[4]; /* a0 */ \ + else \ + _nr = (_r).regs[2]; /* v0 */ \ + _nr; \ +}) +# define reg_retval(x) (x).regs[2] /* v0 */ +# define reg_sp(x) (x).regs[29] /* sp */ +# define reg_arg1(x) \ + ((x).regs[2] == __NR_O32_Linux ? (x).regs[5] : (x).regs[4]) +# define reg_set_arg1(_r, _v) do { \ + if ((_r).regs[2] == __NR_O32_Linux) \ + (_r).regs[5] = _v; /* a1 */ \ + else \ + (_r).regs[4] = _v; /* a0 */ \ +} while (0) +# define reg_arg2(x) \ + ((x).regs[2] == __NR_O32_Linux ? (x).regs[6] : (x).regs[5]) +# define reg_set_arg2(_r, _v) do { \ + if ((_r).regs[2] == __NR_O32_Linux) \ + (_r).regs[6] = _v; /* a2 */ \ + else \ + (_r).regs[5] = _v; /* a1 */ \ +} while (0) +# define reg_arg3(x) \ + ((x).regs[2] == __NR_O32_Linux ? (x).regs[7] : (x).regs[6]) +# define reg_set_arg3(_r, _v) do { \ + if ((_r).regs[2] == __NR_O32_Linux) \ + (_r).regs[7] = _v; /* a3 */ \ + else \ + (_r).regs[6] = _v; /* a2 */ \ +} while (0) +/* XXX - reg_arg4 probably wrong for syscall() type calls on 032. */ +# define reg_arg4(x) \ + ((x).regs[2] == __NR_O32_Linux ? (x).regs[8] : (x).regs[7]) +# define reg_set_arg4(_r, _v) do { \ + if ((_r).regs[2] == __NR_O32_Linux) \ + (_r).regs[8] = _v; /* a4 */ \ + else \ + (_r).regs[7] = _v; /* a3 */ \ +} while (0) +# define reg_set_syscall(_r, _nr) do { \ + if ((_r).regs[2] == __NR_O32_Linux) \ + (_r).regs[4] = _nr; /* a0 */ \ + else \ + (_r).regs[2] = _nr; /* v0 */ \ +} while (0) +#elif defined(__powerpc__) +# if defined(__powerpc64__) +# if BYTE_ORDER == LITTLE_ENDIAN +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC64LE +# else +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC64 +# endif +# else +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC +# endif +# define sudo_pt_regs struct pt_regs +# define reg_syscall(x) (x).gpr[0] /* r0 */ +# define reg_retval(x) (x).gpr[3] /* r3 */ +# define reg_sp(x) (x).gpr[1] /* r1 */ +# define reg_arg1(x) (x).orig_gpr3 /* r3 */ +# define reg_arg2(x) (x).gpr[4] /* r4 */ +# define reg_arg3(x) (x).gpr[5] /* r5 */ +# define reg_arg4(x) (x).gpr[6] /* r6 */ +# define reg_set_retval(_r, _v) do { \ + if (((_r).trap & 0xfff0) == 0x3000) { \ + /* scv 0 system call, uses negative error code for result. */ \ + reg_retval(_r) = (_v); \ + } else { \ + /* \ + * Set CR0 SO bit to indicate a syscall error, which is stored \ + * as a positive error code. \ + */ \ + reg_retval(_r) = -(_v); \ + (_r).ccr |= 0x10000000; \ + } \ +} while (0) +#elif defined(__riscv) && __riscv_xlen == 64 +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_RISCV64 +# define sudo_pt_regs struct user_regs_struct +# define reg_syscall(x) (x).a7 +# define reg_retval(x) (x).a0 +# define reg_sp(x) (x).sp +# define reg_arg1(x) (x).a0 +# define reg_arg2(x) (x).a1 +# define reg_arg3(x) (x).a2 +# define reg_arg4(x) (x).a3 +#elif defined(__s390__) +/* + * Both the syscall number and return value are stored in r2 for + * the s390 ptrace API. The first argument is stored in orig_gpr2. + */ +# if defined(__s390x__) +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_S390X +# else +# define SECCOMP_AUDIT_ARCH AUDIT_ARCH_S390 +# endif +# define sudo_pt_regs s390_regs +# define reg_syscall(x) (x).gprs[2] /* r2 */ +# define reg_retval(x) (x).gprs[2] /* r2 */ +# define reg_sp(x) (x).gprs[15] /* r15 */ +# define reg_arg1(x) (x).orig_gpr2 /* r2 */ +# define reg_arg2(x) (x).gprs[3] /* r3 */ +# define reg_arg3(x) (x).gprs[4] /* r4 */ +# define reg_arg4(x) (x).gprs[5] /* r6 */ +#else +# error "Do not know how to find your architecture's registers" +#endif + +/* + * Compat definitions for running 32-bit binaries on 64-bit platforms. + * We must define the register struct too since there is no way to + * get it directly from the system headers. + * + * The value of SECCOMP_AUDIT_ARCH_COMPAT is used when matching the + * architecture in the seccomp(2) filter. We can tell when the compat + * arch matched by inspecting the message returned by PTRACE_GETEVENTMSG. + */ +#if defined(__x86_64__) +struct i386_user_regs_struct { + unsigned int ebx; + unsigned int ecx; + unsigned int edx; + unsigned int esi; + unsigned int edi; + unsigned int ebp; + unsigned int eax; + unsigned int xds; + unsigned int xes; + unsigned int xfs; + unsigned int xgs; + unsigned int orig_eax; + unsigned int eip; + unsigned int xcs; + unsigned int eflags; + unsigned int esp; + unsigned int xss; +}; +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_I386 +# define COMPAT_execve 11 +# define COMPAT_execveat 358 +# define compat_sudo_pt_regs struct i386_user_regs_struct +# define compat_reg_syscall(x) (x).orig_eax +# define compat_reg_retval(x) (x).eax +# define compat_reg_sp(x) (x).esp +# define compat_reg_arg1(x) (x).ebx +# define compat_reg_arg2(x) (x).ecx +# define compat_reg_arg3(x) (x).edx +# define compat_reg_arg4(x) (x).esi +#elif defined(__aarch64__) +struct arm_pt_regs { + unsigned int uregs[18]; +}; +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_ARM +# define COMPAT_execve 11 +# define COMPAT_execveat 387 +# define compat_sudo_pt_regs struct arm_pt_regs +# define compat_reg_syscall(x) (x).uregs[7] /* r7 */ +# define compat_reg_retval(x) (x).uregs[0] /* r0 */ +# define compat_reg_sp(x) (x).uregs[13] /* r13 */ +# define compat_reg_arg1(x) (x).uregs[0] /* r0 */ +# define compat_reg_arg2(x) (x).uregs[1] /* r1 */ +# define compat_reg_arg3(x) (x).uregs[2] /* r2 */ +# define compat_reg_arg4(x) (x).uregs[3] /* r3 */ +# define compat_reg_set_syscall(_r, _nr) reg_set_syscall(_r, _nr) +#elif defined(__mips__) +# if _MIPS_SIM == _MIPS_SIM_ABI64 +/* MIPS o32/n32 binary compatibility on a mips64 system. */ +# if BYTE_ORDER == LITTLE_ENDIAN +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_MIPSEL +# define SECCOMP_AUDIT_ARCH_COMPAT2 AUDIT_ARCH_MIPSEL64N32 +# else +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_MIPS +# define SECCOMP_AUDIT_ARCH_COMPAT2 AUDIT_ARCH_MIPS64N32 +# endif +# define COMPAT_execve __NR_O32_Linux + 11 +# define COMPAT_execveat __NR_O32_Linux + 356 +# define COMPAT2_execve __NR_N32_Linux + 57 +# define COMPAT2_execveat __NR_N32_Linux + 320 +# elif _MIPS_SIM == _MIPS_SIM_NABI32 +# if BYTE_ORDER == LITTLE_ENDIAN +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_MIPSEL +# else +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_MIPS +# endif +# define COMPAT_execve __NR_O32_Linux + 11 +# define COMPAT_execveat __NR_O32_Linux + 356 +# endif /* _MIPS_SIM_ABI64 */ +/* MIPS ABIs use a common ptrace interface. */ +# define compat_sudo_pt_regs struct pt_regs +# define compat_reg_syscall(x) reg_syscall(x) +# define compat_reg_retval(x) reg_retval(x) +# define compat_reg_sp(x) reg_sp(x) +# define compat_reg_arg1(x) reg_arg1(x) +# define compat_reg_set_arg1(_r, _v) reg_set_arg1(_r, _v) +# define compat_reg_arg2(x) reg_arg2(x) +# define compat_reg_set_arg2(_r, _v) reg_set_arg2(_r, _v) +# define compat_reg_arg3(x) reg_arg3(x) +# define compat_reg_set_arg3(_r, _v) reg_set_arg3(_r, _v) +# define compat_reg_arg4(x) reg_arg4(x) +# define compat_reg_set_arg4(_r, _v) reg_set_arg4(_r, _v) +# define compat_reg_set_syscall(_r, _nr) reg_set_syscall(_r, _nr) +#elif defined(__powerpc64__) +struct ppc_pt_regs { + unsigned int gpr[32]; + unsigned int nip; + unsigned int msr; + unsigned int orig_gpr3; + unsigned int ctr; + unsigned int link; + unsigned int xer; + unsigned int ccr; + unsigned int mq; + unsigned int trap; + unsigned int dar; + unsigned int dsisr; + unsigned int result; +}; +# if BYTE_ORDER == LITTLE_ENDIAN +/* There is no AUDIT_ARCH_PPCLE define. */ +# define SECCOMP_AUDIT_ARCH_COMPAT (AUDIT_ARCH_PPC|__AUDIT_ARCH_LE) +# else +# define SECCOMP_AUDIT_ARCH_COMPAT AUDIT_ARCH_PPC +# endif +# define COMPAT_execve __NR_execve +# define COMPAT_execveat __NR_execveat +# define compat_sudo_pt_regs struct ppc_pt_regs +# define compat_reg_syscall(x) (x).gpr[0] /* r0 */ +# define compat_reg_retval(x) (x).gpr[3] /* r3 */ +# define compat_reg_sp(x) (x).gpr[1] /* r1 */ +# define compat_reg_arg1(x) (x).orig_gpr3 /* r3 */ +# define compat_reg_arg2(x) (x).gpr[4] /* r4 */ +# define compat_reg_arg3(x) (x).gpr[5] /* r5 */ +# define compat_reg_arg4(x) (x).gpr[6] /* r6 */ +# define compat_reg_set_retval(_r, _v) reg_set_retval(_r, _v) +#endif + +/* Set the syscall number the "normal" way by default. */ +#ifndef reg_set_syscall +# define reg_set_syscall(_r, _nr) do { \ + reg_syscall(_r) = (_nr); \ +} while (0) +#endif +#ifndef compat_reg_set_syscall +# define compat_reg_set_syscall(_r, _nr) do { \ + compat_reg_syscall(_r) = (_nr); \ +} while (0) +#endif + +/* Set the syscall return value the "normal" way by default. */ +#ifndef reg_set_retval +# define reg_set_retval(_r, _v) do { \ + reg_retval(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_retval +# define compat_reg_set_retval(_r, _v) do { \ + compat_reg_retval(_r) = (_v); \ +} while (0) +#endif + +/* Set the syscall arguments the "normal" way by default. */ +#ifndef reg_set_arg1 +# define reg_set_arg1(_r, _v) do { \ + reg_arg1(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg1 +# define compat_reg_set_arg1(_r, _v) do { \ + compat_reg_arg1(_r) = (_v); \ +} while (0) +#endif +#ifndef reg_set_arg2 +# define reg_set_arg2(_r, _v) do { \ + reg_arg2(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg2 +# define compat_reg_set_arg2(_r, _v) do { \ + compat_reg_arg2(_r) = (_v); \ +} while (0) +#endif +#ifndef reg_set_arg3 +# define reg_set_arg3(_r, _v) do { \ + reg_arg3(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg3 +# define compat_reg_set_arg3(_r, _v) do { \ + compat_reg_arg3(_r) = (_v); \ +} while (0) +#endif +#ifndef reg_set_arg4 +# define reg_set_arg4(_r, _v) do { \ + reg_arg4(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg4 +# define compat_reg_set_arg4(_r, _v) do { \ + compat_reg_arg4(_r) = (_v); \ +} while (0) +#endif + +/* Set the syscall arguments the "normal" way by default. */ +#ifndef reg_set_arg1 +# define reg_set_arg1(_r, _v) do { \ + reg_arg1(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg1 +# define compat_reg_set_arg1(_r, _v) do { \ + compat_reg_arg1(_r) = (_v); \ +} while (0) +#endif +#ifndef reg_set_arg2 +# define reg_set_arg2(_r, _v) do { \ + reg_arg2(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg2 +# define compat_reg_set_arg2(_r, _v) do { \ + compat_reg_arg2(_r) = (_v); \ +} while (0) +#endif +#ifndef reg_set_arg3 +# define reg_set_arg3(_r, _v) do { \ + reg_arg3(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg3 +# define compat_reg_set_arg3(_r, _v) do { \ + compat_reg_arg3(_r) = (_v); \ +} while (0) +#endif +#ifndef reg_set_arg4 +# define reg_set_arg4(_r, _v) do { \ + reg_arg4(_r) = (_v); \ +} while (0) +#endif +#ifndef compat_reg_set_arg4 +# define compat_reg_set_arg4(_r, _v) do { \ + compat_reg_arg4(_r) = (_v); \ +} while (0) +#endif + +struct sudo_ptrace_regs { + union { + sudo_pt_regs native; +#ifdef SECCOMP_AUDIT_ARCH_COMPAT + compat_sudo_pt_regs compat; +#endif + } u; + unsigned int wordsize; + bool compat; +}; + +#endif /* SUDO_EXEC_PTRACE_H */ |