// https://syzkaller.appspot.com/bug?id=8f371b215532ca2f195df69cb0eb30e52e55d5d0 // 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); } 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"); } 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) { int i, call, thread; int collide = 0; again: for (call = 0; call < 3; 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); if (collide && (call % 2) == 0) break; event_timedwait(&th->done, 50 + (call == 2 ? 500 : 0)); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); if (!collide) { collide = 1; goto again; } } 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 (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) { continue; } kill_and_wait(pid, &status); break; } } } #ifndef __NR_bpf #define __NR_bpf 321 #endif uint64_t r[1] = {0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: syscall(__NR_unshare, 0x400ul); break; case 1: *(uint32_t*)0x20000440 = 0x11; *(uint32_t*)0x20000444 = 6; *(uint64_t*)0x20000448 = 0x20000100; memcpy( (void*)0x20000100, "\x05\x00\x00\x00\x00\x00\x00\x00\x61\x11\x0c\x00\x00\x00\x00\x00\x85" "\x10\x00\x00\x02\x00\x00\x00\x85\x00\x00\x00\x05\x00\x00\x00\x95\x00" "\x00\x00\x00\x00\x00\x00\x95\x00\xa5\x05\x00\x00\x00\x00\x77\x51\xe8" "\xba\x63\x9a\x67\x88\xa3\x41\xcc\xa5\x55\xfe\xdb\xe9\xd8\xf3\xb4\x23" "\xcd\xac\xfa\x7e\x32\xfe\x02\x31\x36\x8b\x22\x64\xf9\xdc\x3f\x45\xf9" "\xf6\x55\x15\xb0\xe1\xa3\x8d\x86\x65\x52\x2b\xe1\x8b\xd1\x0a\x48\xb0" "\x43\xcc\xc4\x26\x46\xd2\x5d\xfd\x73\xa0\x15\xe0\xca\x7f\xc2\x50\x6a" "\x0f\x68\xa7\xd0\x6d\x75\x35\xf7\x86\x69\x07\xdc\x67\x51\xdf\xb2\x65" "\xa0\xe3\xcc\xae\x66\x9e\x17\x3a\x64\x9c\x1c\xfd\x65\x87\xd4\x52\xd6" "\x4e\x7c\xc9\x57\xd7\x75\x78\xf4\xc3\x52\x35\x13\x8d\x55\x21\xf9\x45" "\x35\x59\xc3\x5d\xa8\x60\xe8\xef\xbc\x6f\x2b\x2a\x3e\x31\x73\xd5\x66" "\x1c\xfe\xec\x79\xc6\x6c\x54\xc3", 195); *(uint64_t*)0x20000450 = 0x20000080; memcpy((void*)0x20000080, "GPL\000", 4); *(uint32_t*)0x20000458 = 5; *(uint32_t*)0x2000045c = 0x29e; *(uint64_t*)0x20000460 = 0x2000cf3d; *(uint32_t*)0x20000468 = 0; *(uint32_t*)0x2000046c = 0; *(uint8_t*)0x20000470 = 0; *(uint8_t*)0x20000471 = 0; *(uint8_t*)0x20000472 = 0; *(uint8_t*)0x20000473 = 0; *(uint8_t*)0x20000474 = 0; *(uint8_t*)0x20000475 = 0; *(uint8_t*)0x20000476 = 0; *(uint8_t*)0x20000477 = 0; *(uint8_t*)0x20000478 = 0; *(uint8_t*)0x20000479 = 0; *(uint8_t*)0x2000047a = 0; *(uint8_t*)0x2000047b = 0; *(uint8_t*)0x2000047c = 0; *(uint8_t*)0x2000047d = 0; *(uint8_t*)0x2000047e = 0; *(uint8_t*)0x2000047f = 0; *(uint32_t*)0x20000480 = 0; *(uint32_t*)0x20000484 = 0; *(uint32_t*)0x20000488 = -1; *(uint32_t*)0x2000048c = 6; *(uint64_t*)0x20000490 = 0; *(uint32_t*)0x20000498 = 0; *(uint32_t*)0x2000049c = 0x10; *(uint64_t*)0x200004a0 = 0; *(uint32_t*)0x200004a8 = 0; *(uint32_t*)0x200004ac = 0; *(uint32_t*)0x200004b0 = -1; res = syscall(__NR_bpf, 5ul, 0x20000440ul, 0x70ul); if (res != -1) r[0] = res; break; case 2: *(uint64_t*)0x20000080 = 0x20000040; memcpy((void*)0x20000040, "ext4_find_delalloc_range\000", 25); *(uint32_t*)0x20000088 = r[0]; syscall(__NR_bpf, 0x11ul, 0x20000080ul, 0x10ul); break; } } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); loop(); return 0; }