// autogenerated by syzkaller (http://github.com/google/syzkaller) #ifndef __NR_mmap #define __NR_mmap 9 #endif #ifndef __NR_setsockopt #define __NR_setsockopt 54 #endif #ifndef __NR_syz_fuse_mount #define __NR_syz_fuse_mount 1000004 #endif #ifndef __NR_socket #define __NR_socket 41 #endif #ifndef __NR_syz_emit_ethernet #define __NR_syz_emit_ethernet 1000006 #endif #ifndef __NR_syz_fuseblk_mount #define __NR_syz_fuseblk_mount 1000005 #endif #ifndef __NR_syz_open_dev #define __NR_syz_open_dev 1000002 #endif #ifndef __NR_syz_open_pts #define __NR_syz_open_pts 1000003 #endif #ifndef __NR_syz_test #define __NR_syz_test 1000001 #endif #define SYZ_SANDBOX_NONE 1 #define SYZ_REPEAT 1 #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include const int kFailStatus = 67; const int kErrorStatus = 68; const int kRetryStatus = 69; __attribute__((noreturn)) void fail(const char* msg, ...) { int e = errno; fflush(stdout); va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); exit(kFailStatus); } __attribute__((noreturn)) void exitf(const char* msg, ...) { int e = errno; fflush(stdout); va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); exit(kRetryStatus); } static int flag_debug; void debug(const char* msg, ...) { if (!flag_debug) return; va_list args; va_start(args, msg); vfprintf(stdout, msg, args); va_end(args); fflush(stdout); } __thread int skip_segv; __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* uctx) { if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED)) _longjmp(segv_env, 1); exit(sig); } static void install_segv_handler() { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ { \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ } static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf)); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } static uintptr_t syz_open_pts(uintptr_t a0, uintptr_t a1) { int ptyno = 0; if (ioctl(a0, TIOCGPTN, &ptyno)) return -1; char buf[128]; sprintf(buf, "/dev/pts/%d", ptyno); return open(buf, a1, 0); } static uintptr_t syz_fuse_mount(uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5) { uint64_t target = a0; uint64_t mode = a1; uint64_t uid = a2; uint64_t gid = a3; uint64_t maxread = a4; uint64_t flags = a5; int fd = open("/dev/fuse", O_RDWR); if (fd == -1) return fd; char buf[1024]; sprintf(buf, "fd=%d,user_id=%ld,group_id=%ld,rootmode=0%o", fd, (long)uid, (long)gid, (unsigned)mode & ~3u); if (maxread != 0) sprintf(buf + strlen(buf), ",max_read=%ld", (long)maxread); if (mode & 1) strcat(buf, ",default_permissions"); if (mode & 2) strcat(buf, ",allow_other"); syscall(SYS_mount, "", target, "fuse", flags, buf); return fd; } static uintptr_t syz_fuseblk_mount(uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5, uintptr_t a6, uintptr_t a7) { uint64_t target = a0; uint64_t blkdev = a1; uint64_t mode = a2; uint64_t uid = a3; uint64_t gid = a4; uint64_t maxread = a5; uint64_t blksize = a6; uint64_t flags = a7; int fd = open("/dev/fuse", O_RDWR); if (fd == -1) return fd; if (syscall(SYS_mknodat, AT_FDCWD, blkdev, S_IFBLK, makedev(7, 199))) return fd; char buf[256]; sprintf(buf, "fd=%d,user_id=%ld,group_id=%ld,rootmode=0%o", fd, (long)uid, (long)gid, (unsigned)mode & ~3u); if (maxread != 0) sprintf(buf + strlen(buf), ",max_read=%ld", (long)maxread); if (blksize != 0) sprintf(buf + strlen(buf), ",blksize=%ld", (long)blksize); if (mode & 1) strcat(buf, ",default_permissions"); if (mode & 2) strcat(buf, ",allow_other"); syscall(SYS_mount, blkdev, target, "fuseblk", flags, buf); return fd; } static uintptr_t execute_syscall(int nr, uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5, uintptr_t a6, uintptr_t a7, uintptr_t a8) { switch (nr) { default: return syscall(nr, a0, a1, a2, a3, a4, a5); case __NR_syz_test: return 0; case __NR_syz_open_dev: return syz_open_dev(a0, a1, a2); case __NR_syz_open_pts: return syz_open_pts(a0, a1); case __NR_syz_fuse_mount: return syz_fuse_mount(a0, a1, a2, a3, a4, a5); case __NR_syz_fuseblk_mount: return syz_fuseblk_mount(a0, a1, a2, a3, a4, a5, a6, a7); } } static void setup_main_process() { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); install_segv_handler(); char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_IO); } static int do_sandbox_none() { int pid = fork(); if (pid) return pid; sandbox_common(); loop(); exit(1); } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; int i; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting"); } exitf("opendir(%s) failed", dir); } 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); struct stat st; if (lstat(filename, &st)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } for (i = 0;; i++) { debug("unlink(%s)\n", filename); if (unlink(filename) == 0) break; if (errno == EROFS) { debug("ignoring EROFS\n"); break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); debug("umount(%s)\n", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); for (i = 0;; i++) { debug("rmdir(%s)\n", dir); if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { debug("ignoring EROFS\n"); break; } if (errno == EBUSY) { debug("umount(%s)\n", dir); if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } } static uint64_t current_time_ms() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void test(); void loop() { int iter; for (iter = 0;; iter++) { char cwdbuf[256]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("clone failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); test(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(pid, &status, __WALL | WNOHANG); int errno0 = errno; if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); waitpid(pid, &status, __WALL); break; } } remove_dir(cwdbuf); } } long r[5]; void* thr(void* arg) { switch ((long)arg) { case 0: r[0] = execute_syscall(__NR_mmap, 0x20000000ul, 0xa000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul, 0, 0, 0); break; case 1: r[1] = execute_syscall(__NR_socket, 0xaul, 0x5ul, 0x84ul, 0, 0, 0, 0, 0, 0); break; case 2: r[2] = execute_syscall(__NR_socket, 0x1ful, 0x3ul, 0x6ul, 0, 0, 0, 0, 0, 0); break; case 3: NONFAILING(memcpy( (void*)0x20009000, "\x83\x15\xf6\xdb\x47\x14\xae\xe2\x8d\xb8\x4d\xb9\x0f\x32\xe7" "\xf5\xbc\xa6\xae\x9a\x2f\x19\xed\xf0\x75\x6a\x0b\xf0\x00\xe9" "\xe1\x0e\xb4\xa5\x19\x08\x88\xfc\x8b\x2d\xe2\x9a\x0f\x55\x00" "\x00\x00\x00\x00\x08\x27\xab\x8e\x7d\xcb\xcc\x15\x4e\x79\xe2" "\xd9\xca\x15\xc3\x66\xbd\x44\xa8\x53\x1f\xda\xab\xce\x98\x39" "\x40\x4e\x75\x57\xfd\x57\xc0\x01\x0b\xb0", 85)); r[4] = execute_syscall(__NR_setsockopt, r[1], 0x0ul, 0x40ul, 0x20009000ul, 0x55ul, 0, 0, 0, 0); break; } return 0; } void test() { long i; pthread_t th[8]; memset(r, -1, sizeof(r)); srand(getpid()); for (i = 0; i < 4; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(10000); } for (i = 0; i < 4; i++) { pthread_create(&th[4 + i], 0, thr, (void*)i); if (rand() % 2) usleep(rand() % 10000); } usleep(100000); } int main() { setup_main_process(); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }