// https://syzkaller.appspot.com/bug?id=e2d5aa8cc209f826c6f11663fadb83618fb8dc7e // 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 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 thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } 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 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"); } static void setup_sysctl() { int cad_pid = fork(); if (cad_pid < 0) exit(1); if (cad_pid == 0) { for (;;) sleep(100); } char tmppid[32]; snprintf(tmppid, sizeof(tmppid), "%d", cad_pid); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", tmppid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) { } } kill(cad_pid, SIGKILL); while (waitpid(cad_pid, NULL, 0) != cad_pid) ; } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void execute_one(void) { if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } int i, call, thread; for (call = 0; call < 1; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { 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; } } } void execute_call(int call) { switch (call) { case 0: *(uint32_t*)0x200003c0 = 2; *(uint32_t*)0x200003c4 = 0x80; *(uint8_t*)0x200003c8 = 7; *(uint8_t*)0x200003c9 = 1; *(uint8_t*)0x200003ca = 0; *(uint8_t*)0x200003cb = 0; *(uint32_t*)0x200003cc = 0; *(uint64_t*)0x200003d0 = 0; *(uint64_t*)0x200003d8 = 0; *(uint64_t*)0x200003e0 = 0; STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 0, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 1, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 2, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 3, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 4, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 5, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 6, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 7, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 8, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 9, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 10, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 11, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 12, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 13, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 14, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 15, 2); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 17, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 18, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 19, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 20, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 21, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 22, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 23, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 24, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 25, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 26, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 27, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 28, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 29, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 30, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 31, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 32, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 33, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 34, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 35, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 36, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 37, 1); STORE_BY_BITMASK(uint64_t, , 0x200003e8, 0, 38, 26); *(uint32_t*)0x200003f0 = 7; *(uint32_t*)0x200003f4 = 2; *(uint64_t*)0x200003f8 = 0; *(uint64_t*)0x20000400 = 0; *(uint64_t*)0x20000408 = 0x8300; *(uint64_t*)0x20000410 = 0; *(uint32_t*)0x20000418 = 0; *(uint32_t*)0x2000041c = 0; *(uint64_t*)0x20000420 = 0; *(uint32_t*)0x20000428 = 0; *(uint16_t*)0x2000042c = 0; *(uint16_t*)0x2000042e = 0; *(uint32_t*)0x20000430 = 0; *(uint32_t*)0x20000434 = 0; *(uint64_t*)0x20000438 = 0; syscall(__NR_perf_event_open, /*attr=*/0x200003c0ul, /*pid=*/-1, /*cpu=*/0ul, /*group=*/-1, /*flags=PERF_FLAG_FD_CLOEXEC|PERF_FLAG_FD_OUTPUT*/ 0xaul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); setup_sysctl(); const char* reason; (void)reason; loop(); return 0; }