// https://syzkaller.appspot.com/bug?id=b8408774e9a8138e4a0dadca9adc6ac4ff266f17 // 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 static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { 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); 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 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; for (i = 0; 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 long syz_open_dev(volatile long a0, volatile long a1, volatile long 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; NONFAILING(strncpy(buf, (char*)a0, sizeof(buf) - 1)); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } 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 loop(void) { int i, call, thread; int collide = 0; again: for (call = 0; call < 6; 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, 45); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); if (!collide) { collide = 1; goto again; } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: NONFAILING(memcpy((void*)0x200002c0, "/dev/kvm\000", 9)); syscall(__NR_openat, 0xffffffffffffff9cul, 0x200002c0ul, 0ul, 0ul); break; case 1: NONFAILING(memcpy((void*)0x20000180, "/dev/fb0\000", 9)); res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000180ul, 0ul, 0ul); if (res != -1) r[0] = res; break; case 2: syz_open_dev(0, 5, 0x100); break; case 3: NONFAILING(*(uint32_t*)0x20000000 = 0x504); NONFAILING(*(uint32_t*)0x20000004 = 0); NONFAILING(*(uint32_t*)0x20000008 = 0); NONFAILING(*(uint32_t*)0x2000000c = 0xf0); NONFAILING(*(uint32_t*)0x20000010 = 0); NONFAILING(*(uint32_t*)0x20000014 = 0); NONFAILING(*(uint32_t*)0x20000018 = 4); NONFAILING(*(uint32_t*)0x2000001c = 0); NONFAILING(*(uint32_t*)0x20000020 = 0); NONFAILING(*(uint32_t*)0x20000024 = 0); NONFAILING(*(uint32_t*)0x20000028 = 0); NONFAILING(*(uint32_t*)0x2000002c = 0); NONFAILING(*(uint32_t*)0x20000030 = 0); NONFAILING(*(uint32_t*)0x20000034 = 0); NONFAILING(*(uint32_t*)0x20000038 = 0); NONFAILING(*(uint32_t*)0x2000003c = 0); NONFAILING(*(uint32_t*)0x20000040 = 0); NONFAILING(*(uint32_t*)0x20000044 = 0); NONFAILING(*(uint32_t*)0x20000048 = 0); NONFAILING(*(uint32_t*)0x2000004c = 0); NONFAILING(*(uint32_t*)0x20000050 = 3); NONFAILING(*(uint32_t*)0x20000054 = 0); NONFAILING(*(uint32_t*)0x20000058 = 0); NONFAILING(*(uint32_t*)0x2000005c = 0); NONFAILING(*(uint32_t*)0x20000060 = 0); NONFAILING(*(uint32_t*)0x20000064 = 0); NONFAILING(*(uint32_t*)0x20000068 = 0); NONFAILING(*(uint32_t*)0x2000006c = 0); NONFAILING(*(uint32_t*)0x20000070 = 0); NONFAILING(*(uint32_t*)0x20000074 = 0); NONFAILING(*(uint32_t*)0x20000078 = 0); NONFAILING(*(uint32_t*)0x2000007c = 0); NONFAILING(*(uint32_t*)0x20000080 = 0); NONFAILING(*(uint32_t*)0x20000084 = 0); NONFAILING(*(uint32_t*)0x20000088 = 0); NONFAILING(*(uint32_t*)0x2000008c = 0); NONFAILING(*(uint32_t*)0x20000090 = 0); NONFAILING(*(uint32_t*)0x20000094 = 0); NONFAILING(*(uint32_t*)0x20000098 = 0); NONFAILING(*(uint32_t*)0x2000009c = 0); syscall(__NR_ioctl, r[0], 0x4601, 0x20000000ul); break; case 4: res = syz_open_dev(0xc, 4, 1); if (res != -1) r[1] = res; break; case 5: NONFAILING(*(uint16_t*)0x20000000 = 0x200); NONFAILING(*(uint16_t*)0x20000002 = 2); NONFAILING(*(uint64_t*)0x20000008 = 0x200000c0); NONFAILING(memcpy( (void*)0x200000c0, "\x00\x00\x40\x5a\xf6\xf3\x09\x14\x7a\x2d\xda\xe3\x85\x53\x0f\x98\x1c" "\xc2\x7a\x7a\x3e\x9f\x9d\x4a\x0c\x12\x38\x62\x6f\xbb\xf3\xec\xf5\x0f" "\xee\xcb\x38\x3e\x98\xe0\xb2\xfb\x66\x9d\x7a\xcb\x26\x20\x94\x6a\x5c" "\x80\xcb\x07\x7c\x8a\xbb\xce\x62\xac\xa2\xb4\x6d\x2e\x9c\x53\x41\x72" "\xdb\xa1\x88\x8a\x09\xa0\x66\xe7\xa5\xe6\x18\xf0\x18\x48\x59\x00\x20" "\x0e\x4c\x54\x40\x45\xce\xa0\xe3\xea\x53\x31\x63\x28\xa6\x0a\xba\xc5" "\x00\x9d\x42\x50\x16\xff\xe4\xc3\xba\x81\x18\x79\x90\x87\xb7\x94\xd2" "\x3d\x37\x40\x42\xb4\xd6\x83\x77\x88\xbc\xf7\x35\x94\xf3\xe7\x6c\x3f" "\x49\x48\x78\xa8\xc2\x70\xe1\xa6\x46\x8c\x33\xed\x06\xae\x5e\xf2\x01" "\x90\x97\x50\x54\xa9\xdb\x93\x97\xd1\xf0\x0f\x02\x77\xc3\xa0\x25\x19" "\xf7\x68\x96\xc4\x84\xe8\x80\x6b\xfa\x7d\x5c\x67\xb2\xf2\x18\xb2\xd4" "\x50\xd1\x69\x36\x32\xa3\xc8\x83\x04\xcf\x92\xd2\xff\x7f\x00\x00\x00" "\x00\x00\x00\x96\xce\x1a\xde\xac\x36\x73\xf7\x5e\xc6\x56\xf2\x03\xcd" "\x83\x2f\xbb\xdb\x23\xaa\x83\x69\x98\xa8\x4a\x86\xd1\x74\x7e\xde\xfe" "\x0c\x6b\x80\x89\x92\xee\x18\x46\x9a\x5b\x9e\xee\xfe\xb3\x32\x40\x58" "\x67\x37\x30\xe0\x9f\x4b\x5c\x3c\x23\x5e\xc3\x9e\xb6\x50\x04\xdf\xd8" "\x1d\xaa\x40\x96\x45\x99\xd5\x29\x7b\x6f\xdd\x76\x26\xb9\x6f\x38\x29" "\x06\x00\x00\x00\x00\x00\x00\x00\xaf\x89\xd5\x57\x4e\xdb\x15\x58\xd2" "\x67\x5a\xf9\xae\x7c\xb0\xfe\x16\x50\x1b\xef\x10\xfa\x06\x77\xcf\xb6" "\xce\x0c\x2e\x0b\xa5\xf6\x72\x90\xb8\xbe\xb9\x4f\x0f\xac\x98\x23\xe4" "\x24\x43\x62\x0d\x53\x89\x5c\xf6\x69\x50\x96\xc0\x08\xda\xdd\x5f\x3d" "\x14\xbb\xaa\xd0\x47\x4b\xfb\x01\x49\x95\xdf\x0a\x97\x0d\x65\x59\x7f" "\xf1\x03\x81\xd8\xbb\x3b\xe3\x13\x9a\x4d\x33\xc6\xc2\x1c\xe1\x42\xcd" "\x54\xa1\x7b\x7b\x1b\x9b\x89\xaf\x2b\x36\x32\xb0\xd2\x46\x02\x98\x9c" "\x74\x74\xf5\x70\x81\x61\x12\xe3\x56\x00\x00\x00\x00\x00\x00\x00\x06" "\xcf\xb6\x71\x5e\xef\x4e\x2a\x9b\x37\x21\x1c\x10\x8e\x38\x71\xb9\x2e" "\xc1\x1f\x89\xfb\xcc\x7a\x1f\x47\x20\x6d\x5f\xa4\x1f\x46\xcf\x84\x51" "\x4c\xdf\x2f\xea\x7e\x99\xc6\x82\xec\xe8\x34\x6e\x5b\x9b\x80\x35\xcb" "\x28\x4b\x26\x6a\x42\x81\x8a\x9e\x2d\x5d\x77\x6b\xd1\x0f\x43\x82\x9f" "\x59\x13\xe1\x48\x1c\x1f\x93\x99\xe6\xfd\xcc\x88\xc3\x47\x00\x31\x4e" "\x5b\x53\x94\x1b\x2a\xe5\x40\xa1\xd2\x60\x0c\x91\xdb\xfe\x88\xd7\x90" "\x18\x11\xa2\x88\xa2\x4f\x76\xb1\x7b\x00\x0a\x7f\x6c\xfe\xa9\xb5\xe6" "\xbd\x8c\x0a\xfe\x2e\x7f\x1e\x9c\xb9\x3a\xcf\x31\x8f\xee\x28\x9d\xbf" "\xb6\xe3\x01\xf8\xaf\x99\x26\x2c\x7c\x66\x0a\x5d\x78\x62\x22\xb6\x6c" "\x79\xe8\xac\x39\xc6\x9e\x66\xe5\xd9\xaa\x11\xe3\x4c\x0e\x80\xa4\xa9" "\xd7\x71\x60\x3d\xa3\xc1\xb9\xec\x0b\xf7\x5e\x57\x99\x1b\xbe\x04\x41" "\x7b\xd9\x09\x3b\xdb\x3e\x3b\xa3\xcc\xc7\x09\xc5\x1f\x9a\xd9\xfa\xb9" "\x08\x11\xec\x1f\x9f\xd5\x19\x2d\x16\x85\x9b\x24\x57\xd4\x2c\xaa\xc2" "\xc8\x5a\xbd\x6c\xea\x00\x70\x21\xaa\xd5\x03\x6c\x7b\x00\x50\xb6\x31" "\x56\xca\x00\x9d\x1b\xff\x2b\x46\x1a\xb0\x25\xa7\x47\x23\x0c\xe5\x51" "\x58\x83\x97\xb3\x7a\xda\xd5\x08\xc7\xbb\x23\xef\xb5\xee\x4d\xc5\x78" "\xb3\x6d\xda\x45\x96\x78\x00\xdd\xfc\xb3\x3a\x08\xd9\x97\xed\x68\xbf" "\x77\x46\xc2\x2e\x20\x00\x94\x11\x49\x1a\xc5\x8c\xb9\x60\x51\x01\x41" "\xc7\xc2\xff\x16\x51\xd4\xc9\x35\x82\x1a\x36\x5e\xb2\x21\x47\x65\xa7" "\x14\x00\x04\x00\x00\xa4\xe9\x41\x38\x8b\x02\x7c\xc2\x50\x71\x43\xb3" "\xfb\xae\xaa\xc2\x06\x87\x34\xdd\xb9\x90\x72\x33\x97\x3f\x36\x1a\x2e" "\xea\x42\x33\xe0\x95\xa7\x57\x35\x21\x30\x15\xae\x9f\xe8\x73\xde\x64" "\x40\x83\x01\x9b\x39\x40\x72\x25\xde\xe4\xf2\xac\x3d\x9d\xb5\xbf\xaa" "\x03\xc1\x6a\x39\x4d\x99\xa0\xfa\x1f\xf8\xa0\xfb\x45\x09\x6a\xe3\xe3" "\xac\x48\x5a\x91\x2f\x47\x95\x64\x8d\x64\x98\x0b\xeb\x6a\x4a\x84\x3f" "\x61\x43\xf5\xf6\x91\x83\x9b\x67\x60\x6f\x3d\x10\xd7\x37\x75\x44\x5b" "\x54\x16\x20\x29\x09\xb3\xbe\x00\x00\x9e\xe1\x9e\xe0\x12\xff\x20\xa7" "\xb3\x66\xec\x4a\x9c\x8b\xc8\x10\xfa\x1a\xa3\x1f\x1d\xf2\x19\x33\xf4" "\x68\x84\xc2\xeb\x36\xf0\x45\xd2\x8a\xae\x8c\x13\xf3\x0e\xa2\x39\xd8" "\xcd\x6d\x51\x2f\xfc\xa3\x93\x2a\x70\xb9\x81\x9c\x8f\x60\x25\x94\x18" "\x3f\xa9\x54\x5c\x94\x85\x50\xc1\x06\x22\x8a\x03\x06\x85\x38\xff\x03" "\x00\x00\xce\x92\x16\xc3\x6f\xb4\x13\x5f\xc8\x88\x4c\x34\xe0\x51\x47" "\x50\x6e\xa8\xbd\x59\x31\xf8\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\xc0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00", 1024)); syscall(__NR_ioctl, r[1], 0x4b6c, 0x20000000ul); 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); install_segv_handler(); loop(); return 0; }