diff options
Diffstat (limited to 'tools/testing/selftests/nsfs/owner.c')
-rw-r--r-- | tools/testing/selftests/nsfs/owner.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/tools/testing/selftests/nsfs/owner.c b/tools/testing/selftests/nsfs/owner.c new file mode 100644 index 0000000000..96a976c745 --- /dev/null +++ b/tools/testing/selftests/nsfs/owner.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include <sched.h> +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <sys/prctl.h> +#include <sys/wait.h> + +#define NSIO 0xb7 +#define NS_GET_USERNS _IO(NSIO, 0x1) + +#define pr_err(fmt, ...) \ + ({ \ + fprintf(stderr, "%s:%d:" fmt ": %m\n", \ + __func__, __LINE__, ##__VA_ARGS__); \ + 1; \ + }) + +int main(int argc, char *argvp[]) +{ + int pfd[2], ns, uns, init_uns; + struct stat st1, st2; + char path[128]; + pid_t pid; + char c; + + if (pipe(pfd)) + return 1; + + pid = fork(); + if (pid < 0) + return pr_err("fork"); + if (pid == 0) { + prctl(PR_SET_PDEATHSIG, SIGKILL); + if (unshare(CLONE_NEWUTS | CLONE_NEWUSER)) + return pr_err("unshare"); + close(pfd[0]); + close(pfd[1]); + while (1) + sleep(1); + return 0; + } + close(pfd[1]); + if (read(pfd[0], &c, 1) != 0) + return pr_err("Unable to read from pipe"); + close(pfd[0]); + + snprintf(path, sizeof(path), "/proc/%d/ns/uts", pid); + ns = open(path, O_RDONLY); + if (ns < 0) + return pr_err("Unable to open %s", path); + + uns = ioctl(ns, NS_GET_USERNS); + if (uns < 0) + return pr_err("Unable to get an owning user namespace"); + + if (fstat(uns, &st1)) + return pr_err("fstat"); + + snprintf(path, sizeof(path), "/proc/%d/ns/user", pid); + if (stat(path, &st2)) + return pr_err("stat"); + + if (st1.st_ino != st2.st_ino) + return pr_err("NS_GET_USERNS returned a wrong namespace"); + + init_uns = ioctl(uns, NS_GET_USERNS); + if (uns < 0) + return pr_err("Unable to get an owning user namespace"); + + if (ioctl(init_uns, NS_GET_USERNS) >= 0 || errno != EPERM) + return pr_err("Don't get EPERM"); + + if (unshare(CLONE_NEWUSER)) + return pr_err("unshare"); + + if (ioctl(ns, NS_GET_USERNS) >= 0 || errno != EPERM) + return pr_err("Don't get EPERM"); + if (ioctl(init_uns, NS_GET_USERNS) >= 0 || errno != EPERM) + return pr_err("Don't get EPERM"); + + kill(pid, SIGKILL); + wait(NULL); + return 0; +} |