// https://syzkaller.appspot.com/bug?id=b69d74ba2b304cc715e02370b271ed66b1e24dd9 // 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 #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; 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); } 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_RELAXED)) 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 setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 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 = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 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); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); } int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static void drop_caps(void) { struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) exit(1); const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE); cap_data[0].effective &= ~drop; cap_data[0].permitted &= ~drop; cap_data[0].inheritable &= ~drop; if (syscall(SYS_capset, &cap_hdr, &cap_data)) exit(1); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } loop(); exit(1); } static void close_fds() { int fd; for (fd = 3; fd < 30; fd++) close(fd); } 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 < 8; 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); close_fds(); if (!collide) { collide = 1; goto again; } } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0x0}; void execute_call(int call) { intptr_t res; switch (call) { case 0: syscall(__NR_mmap, 0x20ffd000, 0x2000, 0x400002000007, 0x8812, -1, 0); break; case 1: res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[0] = res; break; case 2: res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[1] = res; break; case 3: res = syscall(__NR_socket, 0x10, 0x803, 0); if (res != -1) r[2] = res; break; case 4: *(uint64_t*)0x200001c0 = 0; *(uint32_t*)0x200001c8 = 0; *(uint64_t*)0x200001d0 = 0x20000180; *(uint64_t*)0x20000180 = 0; *(uint64_t*)0x20000188 = 0; *(uint64_t*)0x200001d8 = 1; *(uint64_t*)0x200001e0 = 0; *(uint64_t*)0x200001e8 = 0; *(uint32_t*)0x200001f0 = 0; syscall(__NR_sendmsg, r[2], 0x200001c0, 0); break; case 5: *(uint32_t*)0x20000200 = 0xa; res = syscall(__NR_getsockname, r[2], 0x20000100, 0x20000200); if (res != -1) r[3] = *(uint32_t*)0x20000104; break; case 6: *(uint64_t*)0x20000240 = 0; *(uint32_t*)0x20000248 = 0; *(uint64_t*)0x20000250 = 0x20000080; *(uint64_t*)0x20000080 = 0x20003e40; memcpy((void*)0x20003e40, "\x48\x01\x00\x00\x24\x00\x07\x05\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00", 20); *(uint32_t*)0x20003e54 = r[3]; memcpy((void*)0x20003e58, "\x00\x00\x00\x00\xf1\xff\xff\xff\x00\x00\x00\x00\x08\x00\x01\x00" "\x72\x65\x64\x00\x1c\x01\x02\x00\x04\x01\x02\x00\x77\x83\xaf\x7a" "\xa5\x52\xeb\x10\x64\x87\x31\x14\x62\xcb\x07\xa4\x1b\x2d\x4a\xa6" "\x25\xa8\x11\xc4\xe1\xd4\xf2\x28\x59\xba\x16\x76\x8b\xc2\x65\xca" "\xdf\xb9\x46\xf0\x47\x8d\x60\x12\x5c\x62\x0f\x5c\x75\x58\x19\x93" "\x27\x7e\xed\xc5\xda\x9c\xe7\x08\x42\x07\x01\x87\x8c\xcc\x94\xc9" "\xb2\xc2\xc1\x32\x55\x2d\xa7\xdb\xe8\xb2\x70\x9d\x09\x3e\x52\xcb" "\x0d\x3f\x3b\xeb\xde\x8a\x18\xd1\x59\x2b\x8b\xf4\xc5\x53\xc8\xfc" "\xf1\x90\x1a\x35\x83\x67\xc4\xf9\x23\x0c\xea\x8b\x6b\xe9\x95\xf2" "\x94\x5f\x5f\xa7\xa7\x63\x55\x76\xf7\x7f\x82\x71\x4d\x85\x71\x40" "\x6b\x73\x2d\x7a\x37\x10\x9c\xa0\x8c\x00\xcc\x02\xd0\xcb\x8a\x2d" "\xaf\xff\xba\xa6\x2b\x8f\x1f\x7f\x69\xae\x9c\xd0\x9f\x45\xb8\x3a" "\x0d\x21\x66\x23\x8b\x61\x01\x93\xb9\x4b\x38\x34\x94\x43\xf9\x9f" "\xa0\x4a\x15\x20\x58\xc8\x60\xf9\xcc\xcb\xa1\xab\x49\x83\x4f\xc5" "\x50\x7f\xa2\x3b\x46\xb5\x71\xf9\x03\xc4\x6c\x15\x67\xbb\xcb\x4f" "\x99\x5f\x7a\x2c\x32\x83\x76\x92\x4b\x9a\x78\x98\x9d\xd0\x5d\xd3" "\x18\x70\x95\x44\xd2\x00\x09\x00\x00\x00\x00\x00\x00\xa8\xc5\x04" "\xf3\x0c\x1c\xe9\xef\x5d\x42\xa6\x84\x24\x5d\xb3\x14\x00\x01\x00" "\xa6\x6c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 304); *(uint64_t*)0x20000088 = 0x148; *(uint64_t*)0x20000258 = 1; *(uint64_t*)0x20000260 = 0; *(uint64_t*)0x20000268 = 0; *(uint32_t*)0x20000270 = 0; syscall(__NR_sendmsg, r[1], 0x20000240, 0); break; case 7: *(uint64_t*)0x20000240 = 0; *(uint32_t*)0x20000248 = 0; *(uint64_t*)0x20000250 = 0x20000080; *(uint64_t*)0x20000080 = 0x20000180; *(uint32_t*)0x20000180 = 0x48; *(uint16_t*)0x20000184 = 0x24; *(uint16_t*)0x20000186 = 0x507; *(uint32_t*)0x20000188 = 0; *(uint32_t*)0x2000018c = 0; *(uint8_t*)0x20000190 = 0; *(uint32_t*)0x20000194 = r[3]; *(uint16_t*)0x20000198 = 0; *(uint16_t*)0x2000019a = 0; *(uint16_t*)0x2000019c = 0; *(uint16_t*)0x2000019e = -1; *(uint16_t*)0x200001a0 = 0; *(uint16_t*)0x200001a2 = 0; *(uint16_t*)0x200001a4 = 8; *(uint16_t*)0x200001a6 = 1; memcpy((void*)0x200001a8, "htb\000", 4); *(uint16_t*)0x200001ac = 0x1c; *(uint16_t*)0x200001ae = 2; *(uint16_t*)0x200001b0 = 0x18; *(uint16_t*)0x200001b2 = 2; *(uint32_t*)0x200001b4 = 3; *(uint32_t*)0x200001b8 = 0; *(uint32_t*)0x200001bc = 0; *(uint32_t*)0x200001c0 = 0; *(uint32_t*)0x200001c4 = 0; *(uint64_t*)0x20000088 = 0x48; *(uint64_t*)0x20000258 = 1; *(uint64_t*)0x20000260 = 0; *(uint64_t*)0x20000268 = 0; *(uint32_t*)0x20000270 = 0; syscall(__NR_sendmsg, r[0], 0x20000240, 0); break; } } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); do_sandbox_none(); return 0; }