// https://syzkaller.appspot.com/bug?id=039bf53503778d3401b657cb99a68e5803f69eae // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __NR_landlock_add_rule #define __NR_landlock_add_rule 445 #endif #ifndef __NR_landlock_create_ruleset #define __NR_landlock_create_ruleset 444 #endif #ifndef __NR_landlock_restrict_self #define __NR_landlock_restrict_self 446 #endif static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; const int umount_flags = MNT_FORCE | UMOUNT_NOFOLLOW; retry: while (umount2(dir, umount_flags) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } struct dirent* ep = 0; while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); while (umount2(filename, umount_flags) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, umount_flags)) exit(1); } } closedir(dp); for (int i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, umount_flags)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); if (symlink("/dev/binderfs", "./binderfs")) { } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { sleep_ms(10); if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 31 00} (length 0x8) // } // mode: open_mode = 0x0 (8 bytes) // ] memcpy((void*)0x200000000340, "./file1\000", 8); syscall(__NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x200000000340ul, /*mode=*/0ul); // mount$tmpfs arguments: [ // src: const = 0x0 (8 bytes) // dst: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 31 00} (length 0x8) // } // type: ptr[in, buffer] { // buffer: {74 6d 70 66 73 00} (length 0x6) // } // flags: mount_flags = 0x8000 (8 bytes) // opts: nil // ] memcpy((void*)0x200000000000, "./file1\000", 8); memcpy((void*)0x200000000080, "tmpfs\000", 6); syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000000ul, /*type=*/0x200000000080ul, /*flags=MS_SILENT*/ 0x8000ul, /*opts=*/0ul); // mkdirat arguments: [ // fd: fd_dir (resource) // path: nil // mode: open_mode = 0x1c0 (8 bytes) // ] syscall(__NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0ul, /*mode=S_IXUSR|S_IWUSR|S_IRUSR*/ 0x1c0ul); // landlock_create_ruleset arguments: [ // attr: ptr[in, landlock_ruleset_attr] { // landlock_ruleset_attr { // handled_access_fs: landlock_access_fs_flags = 0x2001 (8 bytes) // handled_access_net: landlock_access_net_flags = 0x0 (8 bytes) // scoped: landlock_scope_flags = 0x3 (8 bytes) // } // } // size: bytesize = 0x18 (8 bytes) // flags: landlock_create_ruleset_flags = 0x0 (8 bytes) // ] // returns fd_ruleset *(uint64_t*)0x2000000002c0 = 0x2001; *(uint64_t*)0x2000000002c8 = 0; *(uint64_t*)0x2000000002d0 = 3; res = syscall(__NR_landlock_create_ruleset, /*attr=*/0x2000000002c0ul, /*size=*/0x18ul, /*flags=*/0ul); if (res != -1) r[0] = res; // openat$dir arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 31 00} (length 0x8) // } // flags: open_flags = 0x200000 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd_dir memcpy((void*)0x200000000300, "./file1\000", 8); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000300ul, /*flags=O_PATH*/ 0x200000, /*mode=*/0); if (res != -1) r[1] = res; // landlock_add_rule$LANDLOCK_RULE_PATH_BENEATH arguments: [ // ruleset_fd: fd_ruleset (resource) // rule_type: const = 0x1 (8 bytes) // rule_attr: ptr[in, landlock_path_beneath_attr] { // landlock_path_beneath_attr { // allowed_access: landlock_access_fs_flags = 0x2000 (8 bytes) // parent_fd: fd (resource) // } // } // flags: const = 0x0 (8 bytes) // ] *(uint64_t*)0x200000000340 = 0x2000; *(uint32_t*)0x200000000348 = r[1]; syscall(__NR_landlock_add_rule, /*ruleset_fd=*/r[0], /*rule_type=*/1ul, /*rule_attr=*/0x200000000340ul, /*flags=*/0ul); // landlock_restrict_self arguments: [ // ruleset_fd: fd_ruleset (resource) // flags: landlock_restrict_self_flags = 0x0 (8 bytes) // ] syscall(__NR_landlock_restrict_self, /*ruleset_fd=*/r[0], /*flags=*/0ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; use_temporary_dir(); loop(); return 0; }