// https://syzkaller.appspot.com/bug?id=819ff817e7e954b1bfb84d2552f5afac0400f018 // 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 #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); } #define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1) #define BITMASK_LEN_OFF(type, bf_off, bf_len) \ (type)(BITMASK_LEN(type, (bf_len)) << (bf_off)) #define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len) \ if ((bf_off) == 0 && (bf_len) == 0) { \ *(type*)(addr) = (type)(val); \ } else { \ type new_val = *(type*)(addr); \ new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len)); \ new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off); \ *(type*)(addr) = new_val; \ } 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 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; } static void setup_cgroups() { if (mkdir("/syzcgroup", 0777)) { } if (mkdir("/syzcgroup/unified", 0777)) { } if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) { } if (chmod("/syzcgroup/unified", 0777)) { } if (!write_file("/syzcgroup/unified/cgroup.subtree_control", "+cpu +memory +io +pids +rdma")) { } if (mkdir("/syzcgroup/cpu", 0777)) { } if (mount("none", "/syzcgroup/cpu", "cgroup", 0, "cpuset,cpuacct,perf_event,hugetlb")) { } if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) { } if (chmod("/syzcgroup/cpu", 0777)) { } if (mkdir("/syzcgroup/net", 0777)) { } if (mount("none", "/syzcgroup/net", "cgroup", 0, "net_cls,net_prio,devices,freezer")) { } if (chmod("/syzcgroup/net", 0777)) { } } static void setup_binfmt_misc() { if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:syz0::./file0:")) { } if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:yz1::./file0:POC")) { } } 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 = 160 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 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); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } int wait_for_loop(int pid) { if (pid < 0) fail("sandbox fork failed"); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_cgroups(); setup_binfmt_misc(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: while (umount2(dir, MNT_DETACH) == 0) { } 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 execute_one(); extern unsigned long long procid; static void loop() { char cgroupdir[64]; snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid); char cgroupdir_cpu[64]; snprintf(cgroupdir_cpu, sizeof(cgroupdir_cpu), "/syzcgroup/cpu/syz%llu", procid); char cgroupdir_net[64]; snprintf(cgroupdir_net, sizeof(cgroupdir_net), "/syzcgroup/net/syz%llu", procid); if (mkdir(cgroupdir, 0777)) { } if (mkdir(cgroupdir_cpu, 0777)) { } if (mkdir(cgroupdir_net, 0777)) { } int pid = getpid(); char procs_file[128]; snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir); if (!write_file(procs_file, "%d", pid)) { } snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_cpu); if (!write_file(procs_file, "%d", pid)) { } snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_net); if (!write_file(procs_file, "%d", pid)) { } int iter; for (iter = 0;; iter++) { char cwdbuf[32]; 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"); if (symlink(cgroupdir, "./cgroup")) { } if (symlink(cgroupdir_cpu, "./cgroup.cpu")) { } if (symlink(cgroupdir_net, "./cgroup.net")) { } execute_one(); 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 < 3 * 1000) continue; kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } remove_dir(cwdbuf); } } struct thread_t { int created, running, call; pthread_t th; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static int collide; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); if (collide && call % 2) break; struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (__atomic_load_n(&running, __ATOMIC_RELAXED)) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } #ifndef __NR_bpf #define __NR_bpf 321 #endif uint64_t r[1] = {0xffffffffffffffff}; unsigned long long procid; void execute_call(int call) { long res; switch (call) { case 0: *(uint32_t*)0x20000200 = 2; *(uint32_t*)0x20000204 = 0x70; *(uint8_t*)0x20000208 = 0xe6; *(uint8_t*)0x20000209 = 0; *(uint8_t*)0x2000020a = 0; *(uint8_t*)0x2000020b = 0; *(uint32_t*)0x2000020c = 0; *(uint64_t*)0x20000210 = 0; *(uint64_t*)0x20000218 = 0; *(uint64_t*)0x20000220 = 0; STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 0, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 1, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 2, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 3, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 4, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 5, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 6, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 7, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 8, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 9, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 10, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 11, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 12, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 13, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 14, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 15, 2); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 17, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 18, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 19, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 20, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 21, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 22, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 23, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 24, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 25, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 26, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 27, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 28, 1); STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 29, 35); *(uint32_t*)0x20000230 = 0; *(uint32_t*)0x20000234 = 0; *(uint64_t*)0x20000238 = 0; *(uint64_t*)0x20000240 = 0; *(uint64_t*)0x20000248 = 0; *(uint64_t*)0x20000250 = 0; *(uint32_t*)0x20000258 = 0; *(uint32_t*)0x2000025c = 0; *(uint64_t*)0x20000260 = 0; *(uint32_t*)0x20000268 = 0; *(uint16_t*)0x2000026c = 0; *(uint16_t*)0x2000026e = 0; syscall(__NR_perf_event_open, 0x20000200, 0, 0, -1, 0); break; case 1: *(uint32_t*)0x20000a40 = -1; syscall(__NR_setsockopt, -1, 0x29, 0x24, 0x20000a40, 0x173); break; case 2: syscall(__NR_socketpair, 0, 0, 0, 0x20000140); break; case 3: syscall(__NR_socket, 0xa, 1, 0); break; case 4: *(uint32_t*)0x20000280 = 0x12; *(uint32_t*)0x20000284 = 9; *(uint32_t*)0x20000288 = 4; *(uint32_t*)0x2000028c = 1; *(uint32_t*)0x20000290 = 0; *(uint32_t*)0x20000294 = -1; *(uint32_t*)0x20000298 = 0; *(uint8_t*)0x2000029c = 0; *(uint8_t*)0x2000029d = 0; *(uint8_t*)0x2000029e = 0; *(uint8_t*)0x2000029f = 0; *(uint8_t*)0x200002a0 = 0; *(uint8_t*)0x200002a1 = 0; *(uint8_t*)0x200002a2 = 0; *(uint8_t*)0x200002a3 = 0; *(uint8_t*)0x200002a4 = 0; *(uint8_t*)0x200002a5 = 0; *(uint8_t*)0x200002a6 = 0; *(uint8_t*)0x200002a7 = 0; *(uint8_t*)0x200002a8 = 0; *(uint8_t*)0x200002a9 = 0; *(uint8_t*)0x200002aa = 0; *(uint8_t*)0x200002ab = 0; res = syscall(__NR_bpf, 0, 0x20000280, 0x34d); if (res != -1) r[0] = res; break; case 5: *(uint32_t*)0x20000000 = 0; *(uint32_t*)0x20000004 = 0; *(uint32_t*)0x20000008 = 4; *(uint32_t*)0x2000000c = 0; *(uint32_t*)0x20000010 = 0; *(uint32_t*)0x20000014 = -1; *(uint32_t*)0x20000018 = 0; *(uint8_t*)0x2000001c = 0; *(uint8_t*)0x2000001d = 0; *(uint8_t*)0x2000001e = 0; *(uint8_t*)0x2000001f = 0; *(uint8_t*)0x20000020 = 0; *(uint8_t*)0x20000021 = 0; *(uint8_t*)0x20000022 = 0; *(uint8_t*)0x20000023 = 0; *(uint8_t*)0x20000024 = 0; *(uint8_t*)0x20000025 = 0; *(uint8_t*)0x20000026 = 0; *(uint8_t*)0x20000027 = 0; *(uint8_t*)0x20000028 = 0; *(uint8_t*)0x20000029 = 0; *(uint8_t*)0x2000002a = 0; *(uint8_t*)0x2000002b = 0; syscall(__NR_bpf, 0, 0x20000000, 0xce); break; case 6: syscall(__NR_socket, 0x29, 5, 0); break; case 7: *(uint32_t*)0x20000180 = r[0]; *(uint64_t*)0x20000188 = 0x20000000; *(uint64_t*)0x20000190 = 0x20000140; *(uint64_t*)0x20000198 = 0; syscall(__NR_bpf, 2, 0x20000180, 0x20); break; case 8: *(uint32_t*)0x20000180 = r[0]; *(uint64_t*)0x20000188 = 0x20000080; *(uint64_t*)0x20000190 = 0x20000140; *(uint64_t*)0x20000198 = 0; syscall(__NR_bpf, 2, 0x20000180, 0x20); break; } } void execute_one() { execute(9); collide = 1; execute(9); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); char* cwd = get_current_dir_name(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); do_sandbox_none(); } }