/* * Check decoding of mount_setattr syscall. * * Copyright (c) 2019-2021 The strace developers. * All rights reserved. * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "tests.h" #include "scno.h" #include <limits.h> #include <stdio.h> #include <stdint.h> #include <string.h> #include <unistd.h> #include <linux/fcntl.h> #include <linux/mount.h> static const char *rcstr; static long k_mount_setattr(const unsigned int dfd, const void *fname, const unsigned int flags, const void *attr, kernel_ulong_t size) { const kernel_ulong_t fill = (kernel_ulong_t) 0xdefaced00000000ULL; const kernel_ulong_t bad = (kernel_ulong_t) 0xbadc0dedbadc0dedULL; const kernel_ulong_t arg1 = fill | dfd; const kernel_ulong_t arg2 = (uintptr_t) fname; const kernel_ulong_t arg3 = fill | flags; const kernel_ulong_t arg4 = (uintptr_t) attr; const kernel_ulong_t arg5 = size; const long rc = syscall(__NR_mount_setattr, arg1, arg2, arg3, arg4, arg5, bad); rcstr = sprintrc(rc); return rc; } int main(void) { skip_if_unavailable("/proc/self/fd/"); #ifndef PATH_TRACING char *cwd = get_fd_path(get_dir_fd(".")); #endif static const char path_full[] = "/dev/full"; const char *const path = tail_memdup(path_full, sizeof(path_full)); char *const fname = tail_alloc(PATH_MAX); const void *const efault = fname + PATH_MAX; const char *const empty = efault - 1; fill_memory_ex(fname, PATH_MAX, '0', 10); TAIL_ALLOC_OBJECT_CONST_PTR(struct mount_attr, attr); struct mount_attr *const attr_big = tail_alloc(sizeof(*attr_big) + 8); static const struct strval32 valid_flags = { ARG_STR(AT_SYMLINK_NOFOLLOW|AT_NO_AUTOMOUNT|AT_EMPTY_PATH|AT_RECURSIVE) }; const unsigned int dfd = 9; k_mount_setattr(-1, 0, AT_SYMLINK_NOFOLLOW, efault, -1U); #ifndef PATH_TRACING printf("mount_setattr(-1, NULL, %s, %p, %u) = %s\n", "AT_SYMLINK_NOFOLLOW", efault, -1U, rcstr); #endif k_mount_setattr(-100, fname, 0, attr, MOUNT_ATTR_SIZE_VER0 - 1); #ifndef PATH_TRACING printf("mount_setattr(AT_FDCWD<%s>, \"%.*s\"..., 0, %p, %u) = %s\n", cwd, (int) PATH_MAX - 1, fname, attr, MOUNT_ATTR_SIZE_VER0 - 1, rcstr); #endif fname[PATH_MAX - 1] = '\0'; k_mount_setattr(dfd, fname, -1U, 1 + (void *) attr, MOUNT_ATTR_SIZE_VER0); printf("mount_setattr(%d<%s>, \"%s\", %s|%#x, %p, %u) = %s\n", dfd, path, fname, valid_flags.str, ~valid_flags.val, 1 + (void *) attr, MOUNT_ATTR_SIZE_VER0, rcstr); k_mount_setattr(-1, efault, valid_flags.val, 1 + (void *) attr, MOUNT_ATTR_SIZE_VER0 - 1); #ifndef PATH_TRACING printf("mount_setattr(-1, %p, %s, %p, %u) = %s\n", efault, valid_flags.str, 1 + (void *) attr, MOUNT_ATTR_SIZE_VER0 - 1, rcstr); #endif k_mount_setattr(-1, empty, ~valid_flags.val, 0, MOUNT_ATTR_SIZE_VER0); #ifndef PATH_TRACING printf("mount_setattr(-1, \"\", %#x /* AT_??? */, NULL, %u) = %s\n", ~valid_flags.val, MOUNT_ATTR_SIZE_VER0, rcstr); #endif static const struct strval64 valid_attr = { ARG_STR(MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME|MOUNT_ATTR_IDMAP|MOUNT_ATTR_NOSYMFOLLOW) }; for (unsigned int j = 0; j < 4; ++j) { struct mount_attr *const a = j > 1 ? attr_big : attr; const size_t size = j ? sizeof(*a) + 8 : sizeof(*a); if (j == 3) memset(attr_big + 1, 0, 8); else fill_memory(attr_big + 1, 8); a->attr_set = 0xffffffff00000000ULL; a->attr_clr = 0; a->propagation = MS_UNBINDABLE; a->userns_fd = dfd; k_mount_setattr(-1, path, 0, a, size); printf("mount_setattr(-1, \"%s\", 0" ", {attr_set=0xffffffff00000000 /* MOUNT_ATTR_??? */" ", attr_clr=0, propagation=%s, userns_fd=%u", path, "MS_UNBINDABLE", dfd); if (j == 1) printf(", ???"); if (j == 2) { printf(", /* bytes %zu..%zu */ \"\\x80\\x81" "\\x82\\x83\\x84\\x85\\x86\\x87\"", sizeof(*a), sizeof(*a) + 7); } printf("}, %zu) = %s\n", size, rcstr); a->attr_set = valid_attr.val; a->attr_clr = ~valid_attr.val; a->propagation = MS_PRIVATE | MS_SHARED; a->userns_fd = dfd; k_mount_setattr(-1, path, 0, a, size); printf("mount_setattr(-1, \"%s\", 0" ", {attr_set=%s, attr_clr=%#llx /* MOUNT_ATTR_??? */" ", propagation=%#x /* MS_??? */, userns_fd=%d<%s>", path, valid_attr.str, (unsigned long long) a->attr_clr, MS_PRIVATE | MS_SHARED, dfd, path); if (j == 1) printf(", ???"); if (j == 2) { printf(", /* bytes %zu..%zu */ \"\\x80\\x81" "\\x82\\x83\\x84\\x85\\x86\\x87\"", sizeof(*a), sizeof(*a) + 7); } printf("}, %zu) = %s\n", size, rcstr); a->attr_set = MOUNT_ATTR_NOSUID; a->attr_clr = MOUNT_ATTR_NODEV; a->propagation = MS_SLAVE; a->userns_fd = 0xdefaced00000000ULL | dfd; k_mount_setattr(dfd, empty, AT_EMPTY_PATH, a, size); printf("mount_setattr(%d<%s>, \"\", %s, {attr_set=%s, attr_clr=%s" ", propagation=%s, userns_fd=%llu", dfd, path, "AT_EMPTY_PATH", "MOUNT_ATTR_NOSUID", "MOUNT_ATTR_NODEV", "MS_SLAVE", (unsigned long long) a->userns_fd); if (j == 1) printf(", ???"); if (j == 2) { printf(", /* bytes %zu..%zu */ \"\\x80\\x81" "\\x82\\x83\\x84\\x85\\x86\\x87\"", sizeof(*a), sizeof(*a) + 7); } printf("}, %zu) = %s\n", size, rcstr); } puts("+++ exited with 0 +++"); return 0; }