// https://syzkaller.appspot.com/bug?id=e6ea4a97f963d77dc94e7a1e6524b78bbc8636b0 // 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 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 uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t 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; strncpy(buf, (char*)a0, sizeof(buf)); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 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_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 loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 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)) { } } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; setup_cgroups(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } static int inject_fault(int nth) { int fd; char buf[16]; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exitf("failed to open /proc/thread-self/fail-nth"); sprintf(buf, "%d", nth + 1); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exitf("failed to write /proc/thread-self/fail-nth"); return fd; } 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 (running) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } uint64_t r[2] = {0x0, 0xffffffffffffffff}; unsigned long long procid; void execute_call(int call) { long res; switch (call) { case 0: memcpy((void*)0x200001c0, "./file0", 8); syscall(__NR_mkdir, 0x200001c0, 0); break; case 1: memcpy((void*)0x20000400, "/dev/usbmon#", 13); syz_open_dev(0x20000400, 0, 0); break; case 2: *(uint32_t*)0x20223000 = 2; *(uint32_t*)0x20223004 = 0x78; *(uint8_t*)0x20223008 = 0xe3; *(uint8_t*)0x20223009 = 0; *(uint8_t*)0x2022300a = 0; *(uint8_t*)0x2022300b = 0; *(uint32_t*)0x2022300c = 0; *(uint64_t*)0x20223010 = 0; *(uint64_t*)0x20223018 = 0; *(uint64_t*)0x20223020 = 0; STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 0, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 1, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 2, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 3, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 4, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 1, 5, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 6, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 7, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 8, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 9, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 10, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 11, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 12, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 13, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 14, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 15, 2); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 17, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 18, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 19, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 20, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 21, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 22, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 23, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 24, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 25, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 26, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 27, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 28, 1); STORE_BY_BITMASK(uint64_t, 0x20223028, 0, 29, 35); *(uint32_t*)0x20223030 = 0; *(uint32_t*)0x20223034 = 0; *(uint64_t*)0x20223038 = 0x20000000; *(uint64_t*)0x20223040 = 0; *(uint64_t*)0x20223048 = 0; *(uint64_t*)0x20223050 = 0; *(uint32_t*)0x20223058 = 0; *(uint32_t*)0x2022305c = 0; *(uint64_t*)0x20223060 = 0; *(uint32_t*)0x20223068 = 0; *(uint16_t*)0x2022306c = 0; *(uint16_t*)0x2022306e = 0; syscall(__NR_perf_event_open, 0x20223000, 0, 0, -1, 0); break; case 3: *(uint32_t*)0x20001a80 = 0xe8; res = syscall(__NR_getsockopt, -1, 0, 0x10, 0x20001980, 0x20001a80); if (res != -1) r[0] = *(uint32_t*)0x200019b4; break; case 4: memcpy((void*)0x200004c0, "./file0", 8); syscall(__NR_chown, 0x200004c0, r[0], 0); break; case 5: memcpy((void*)0x200003c0, "./file0", 8); memcpy((void*)0x20000380, "./file0", 8); memcpy((void*)0x20000300, "cgroup2", 8); syscall(__NR_mount, 0x200003c0, 0x20000380, 0x20000300, 0, 0); break; case 6: memcpy((void*)0x2001bff4, "./file0", 8); res = syscall(__NR_open, 0x2001bff4, 0, 0); if (res != -1) r[1] = res; break; case 7: memcpy((void*)0x20000280, "./file0", 8); write_file("/sys/kernel/debug/failslab/ignore-gfp-wait", "N"); write_file("/sys/kernel/debug/fail_futex/ignore-private", "N"); inject_fault(52); syscall(__NR_mkdirat, r[1], 0x20000280, 0x20); break; case 8: memcpy((void*)0x20000180, "./file0", 8); syscall(__NR_open, 0x20000180, 0, 0); break; } } void loop() { execute(9); collide = 1; execute(9); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); use_temporary_dir(); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }