// https://syzkaller.appspot.com/bug?id=6dcd14a729df98f989c7b76d254226ae67084efd // autogenerated by syzkaller (http://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 #include #include #include #include #include #include #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include const int kFailStatus = 67; const int kRetryStatus = 69; static void fail(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); } static void exitf(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit(kRetryStatus); } 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 use_temporary_dir() { 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 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 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 = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &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); #define CLONE_NEWCGROUP 0x02000000 unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_NEWCGROUP); unshare(CLONE_NEWNET); unshare(CLONE_NEWUTS); unshare(CLONE_SYSVSEM); } static int do_sandbox_none(int executor_pid, bool enable_tun) { unshare(CLONE_NEWPID); int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; sandbox_common(); loop(); doexit(1); } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting", dir); } 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; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { break; } if (errno == EBUSY) { 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 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("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); test(); doexit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(-1, &status, __WALL | WNOHANG); if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } } remove_dir(cwdbuf); } } #ifndef __NR_write #define __NR_write 4 #endif #ifndef __NR_readv #define __NR_readv 145 #endif #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_getsockopt #define __NR_getsockopt 365 #endif #ifndef __NR_timer_settime #define __NR_timer_settime 260 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 long r[3]; void test() { memset(r, -1, sizeof(r)); syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); memcpy((void*)0x20000000, "/dev/sg#", 9); r[0] = syz_open_dev(0x20000000, 0, 2); *(uint32_t*)0x207a0000 = 0x10; if (syscall(__NR_getsockopt, r[0], 1, 0x14, 0x20538000, 0x207a0000) != -1) r[1] = *(uint32_t*)0x20538000; *(uint32_t*)0x20ce7fe0 = 0; *(uint32_t*)0x20ce7fe4 = 0; *(uint32_t*)0x20ce7fe8 = r[1]; *(uint32_t*)0x20ce7fec = 0; if (syscall(__NR_timer_settime, 0, 0, 0x20ce7fe0, 0x20e88fe0) != -1) r[2] = *(uint32_t*)0x20e88fe8; *(uint32_t*)0x20001000 = r[2]; *(uint32_t*)0x20001004 = 6; *(uint16_t*)0x20001008 = 0; *(uint16_t*)0x2000100a = 0; *(uint32_t*)0x2000100c = 0; *(uint32_t*)0x20001010 = 0; *(uint32_t*)0x20001014 = 0; *(uint16_t*)0x20001018 = 0; *(uint16_t*)0x2000101a = 0; *(uint32_t*)0x2000101c = 7; *(uint32_t*)0x20001020 = 0; *(uint32_t*)0x20001024 = 0x2710; *(uint16_t*)0x20001028 = 9; *(uint16_t*)0x2000102a = 0; *(uint32_t*)0x2000102c = 0; *(uint32_t*)0x20001030 = 0; *(uint32_t*)0x20001034 = 0; *(uint16_t*)0x20001038 = 0; *(uint16_t*)0x2000103a = 0; *(uint32_t*)0x2000103c = 0; syscall(__NR_write, r[0], 0x20001000, 0x60); *(uint32_t*)0x20b16000 = 0x20dc8000; *(uint32_t*)0x20b16004 = 0xa5; syscall(__NR_readv, r[0], 0x20b16000, 1); } int main() { char* cwd = get_current_dir_name(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_none(0, false); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } }