// https://syzkaller.appspot.com/bug?id=5735d842f7ea3ed9220aca64952ac4aba7ba741c // 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 __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); } #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 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 loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 160 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 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); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } static int real_uid; static int real_gid; __attribute__((aligned(64 << 10))) static char sandbox_stack[1 << 20]; static int namespace_sandbox_proc(void* arg) { sandbox_common(); write_file("/proc/self/setgroups", "deny"); if (!write_file("/proc/self/uid_map", "0 %d 1\n", real_uid)) fail("write of /proc/self/uid_map failed"); if (!write_file("/proc/self/gid_map", "0 %d 1\n", real_gid)) fail("write of /proc/self/gid_map failed"); if (unshare(CLONE_NEWNET)) fail("unshare(CLONE_NEWNET)"); if (mkdir("./syz-tmp", 0777)) fail("mkdir(syz-tmp) failed"); if (mount("", "./syz-tmp", "tmpfs", 0, NULL)) fail("mount(tmpfs) failed"); if (mkdir("./syz-tmp/newroot", 0777)) fail("mkdir failed"); if (mkdir("./syz-tmp/newroot/dev", 0700)) fail("mkdir failed"); unsigned mount_flags = MS_BIND | MS_REC | MS_PRIVATE; if (mount("/dev", "./syz-tmp/newroot/dev", NULL, mount_flags, NULL)) fail("mount(dev) failed"); if (mkdir("./syz-tmp/newroot/proc", 0700)) fail("mkdir failed"); if (mount(NULL, "./syz-tmp/newroot/proc", "proc", 0, NULL)) fail("mount(proc) failed"); if (mkdir("./syz-tmp/newroot/selinux", 0700)) fail("mkdir failed"); const char* selinux_path = "./syz-tmp/newroot/selinux"; if (mount("/selinux", selinux_path, NULL, mount_flags, NULL)) { if (errno != ENOENT) fail("mount(/selinux) failed"); if (mount("/sys/fs/selinux", selinux_path, NULL, mount_flags, NULL) && errno != ENOENT) fail("mount(/sys/fs/selinux) failed"); } if (mkdir("./syz-tmp/newroot/sys", 0700)) fail("mkdir failed"); if (mount(NULL, "./syz-tmp/newroot/sys", "sysfs", 0, NULL)) fail("mount(sysfs) failed"); if (mkdir("./syz-tmp/pivot", 0777)) fail("mkdir failed"); if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) { if (chdir("./syz-tmp")) fail("chdir failed"); } else { if (chdir("/")) fail("chdir failed"); if (umount2("./pivot", MNT_DETACH)) fail("umount failed"); } if (chroot("./newroot")) fail("chroot failed"); if (chdir("/")) fail("chdir failed"); 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)) fail("capget failed"); cap_data[0].effective &= ~(1 << CAP_SYS_PTRACE); cap_data[0].permitted &= ~(1 << CAP_SYS_PTRACE); cap_data[0].inheritable &= ~(1 << CAP_SYS_PTRACE); if (syscall(SYS_capset, &cap_hdr, &cap_data)) fail("capset failed"); loop(); doexit(1); } static int do_sandbox_namespace(void) { int pid; real_uid = getuid(); real_gid = getgid(); mprotect(sandbox_stack, 4096, PROT_NONE); pid = clone(namespace_sandbox_proc, &sandbox_stack[sizeof(sandbox_stack) - 64], CLONE_NEWUSER | CLONE_NEWPID, 0); if (pid < 0) fail("sandbox clone failed"); return pid; } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } 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; } } } } #ifndef __NR_bpf #define __NR_bpf 321 #endif uint64_t r[1] = {0x0}; unsigned long long procid; void execute_call(int call) { long res; switch (call) { case 0: syscall(__NR_socketpair, 5, 9, 3, 0x200003c0); break; case 1: *(uint64_t*)0x20001d40 = 0x20000880; *(uint32_t*)0x20001d48 = 0x80; *(uint64_t*)0x20001d50 = 0x20001c80; *(uint64_t*)0x20001c80 = 0x20000900; *(uint64_t*)0x20001c88 = 0xb; *(uint64_t*)0x20001c90 = 0x20000940; *(uint64_t*)0x20001c98 = 0xd3; *(uint64_t*)0x20001ca0 = 0x20000a40; *(uint64_t*)0x20001ca8 = 0x1000; *(uint64_t*)0x20001cb0 = 0x20001a40; *(uint64_t*)0x20001cb8 = 0; *(uint64_t*)0x20001cc0 = 0x20001a80; *(uint64_t*)0x20001cc8 = 0x2d; *(uint64_t*)0x20001cd0 = 0x20001ac0; *(uint64_t*)0x20001cd8 = 9; *(uint64_t*)0x20001ce0 = 0x20001b00; *(uint64_t*)0x20001ce8 = 0x87; *(uint64_t*)0x20001cf0 = 0x20001bc0; *(uint64_t*)0x20001cf8 = 0x4f; *(uint64_t*)0x20001d00 = 0x20001c40; *(uint64_t*)0x20001d08 = 0x1e; *(uint64_t*)0x20001d58 = 9; *(uint64_t*)0x20001d60 = 0; *(uint64_t*)0x20001d68 = 0; *(uint32_t*)0x20001d70 = 0; res = syscall(__NR_recvmsg, -1, 0x20001d40, 0x141); if (res != -1) r[0] = *(uint32_t*)0x20000884; break; case 2: *(uint32_t*)0x20001d80 = 0x12; *(uint32_t*)0x20001d84 = 0xe; *(uint64_t*)0x20001d88 = 0x20000140; STORE_BY_BITMASK(uint8_t, 0x20000140, 3, 0, 3); STORE_BY_BITMASK(uint8_t, 0x20000140, 0, 3, 2); STORE_BY_BITMASK(uint8_t, 0x20000140, 3, 5, 3); STORE_BY_BITMASK(uint8_t, 0x20000141, 0xa, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20000141, 0xb, 4, 4); *(uint16_t*)0x20000142 = 0xfff1; *(uint32_t*)0x20000144 = 0xfffffffc; *(uint8_t*)0x20000150 = 8; *(uint8_t*)0x20000151 = 5; *(uint16_t*)0x20000152 = 2; *(uint32_t*)0x20000154 = 8; STORE_BY_BITMASK(uint8_t, 0x20000160, 3, 0, 3); STORE_BY_BITMASK(uint8_t, 0x20000160, 1, 3, 2); STORE_BY_BITMASK(uint8_t, 0x20000160, 1, 5, 3); STORE_BY_BITMASK(uint8_t, 0x20000161, 2, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20000161, 6, 4, 4); *(uint16_t*)0x20000162 = 0x32; *(uint32_t*)0x20000164 = 0xfffffffc; STORE_BY_BITMASK(uint8_t, 0x20000170, 5, 0, 3); STORE_BY_BITMASK(uint8_t, 0x20000170, 0xfa, 3, 1); STORE_BY_BITMASK(uint8_t, 0x20000170, 2, 4, 4); STORE_BY_BITMASK(uint8_t, 0x20000171, 0xe, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20000171, 0xf, 4, 4); *(uint16_t*)0x20000172 = 0; *(uint32_t*)0x20000174 = 0; *(uint8_t*)0x20000180 = 0x85; *(uint8_t*)0x20000181 = 0; *(uint16_t*)0x20000182 = 0; *(uint32_t*)0x20000184 = 0x3b; STORE_BY_BITMASK(uint8_t, 0x20000190, 7, 0, 3); STORE_BY_BITMASK(uint8_t, 0x20000190, 1, 3, 1); STORE_BY_BITMASK(uint8_t, 0x20000190, 5, 4, 4); STORE_BY_BITMASK(uint8_t, 0x20000191, 0xf, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20000191, 6, 4, 4); *(uint16_t*)0x20000192 = 0xfff8; *(uint32_t*)0x20000194 = 8; *(uint8_t*)0x200001a0 = 0x85; *(uint8_t*)0x200001a1 = 0; *(uint16_t*)0x200001a2 = 0; *(uint32_t*)0x200001a4 = 0x13; *(uint64_t*)0x20001d90 = 0x200001c0; memcpy((void*)0x200001c0, "syzkaller", 10); *(uint32_t*)0x20001d98 = 0x94; *(uint32_t*)0x20001d9c = 0xd4; *(uint64_t*)0x20001da0 = 0x20000200; *(uint32_t*)0x20001da8 = 0x41100; *(uint32_t*)0x20001dac = 1; *(uint8_t*)0x20001db0 = 0; *(uint8_t*)0x20001db1 = 0; *(uint8_t*)0x20001db2 = 0; *(uint8_t*)0x20001db3 = 0; *(uint8_t*)0x20001db4 = 0; *(uint8_t*)0x20001db5 = 0; *(uint8_t*)0x20001db6 = 0; *(uint8_t*)0x20001db7 = 0; *(uint8_t*)0x20001db8 = 0; *(uint8_t*)0x20001db9 = 0; *(uint8_t*)0x20001dba = 0; *(uint8_t*)0x20001dbb = 0; *(uint8_t*)0x20001dbc = 0; *(uint8_t*)0x20001dbd = 0; *(uint8_t*)0x20001dbe = 0; *(uint8_t*)0x20001dbf = 0; *(uint32_t*)0x20001dc0 = r[0]; *(uint32_t*)0x20001dc4 = 3; syscall(__NR_bpf, 5, 0x20001d80, 0x48); break; case 3: *(uint32_t*)0x20000100 = 0; *(uint32_t*)0x20000104 = -1; *(uint32_t*)0x20000108 = 7; *(uint32_t*)0x2000010c = 1; *(uint32_t*)0x20000110 = 0; syscall(__NR_bpf, 9, 0x20000100, 0x14); break; case 4: *(uint32_t*)0x20000040 = 0; *(uint32_t*)0x20000044 = 0x70; *(uint8_t*)0x20000048 = 0; *(uint8_t*)0x20000049 = 0; *(uint8_t*)0x2000004a = 0; *(uint8_t*)0x2000004b = 0; *(uint32_t*)0x2000004c = 0; *(uint64_t*)0x20000050 = 0; *(uint64_t*)0x20000058 = 0; *(uint64_t*)0x20000060 = 0; STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 0, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 1, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 2, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 3, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 4, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 5, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 6, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 7, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 8, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 9, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 10, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 11, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 12, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 13, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 14, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 15, 2); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 17, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 18, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 19, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 20, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 21, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 22, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 23, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 24, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 25, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 2, 26, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 27, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 28, 1); STORE_BY_BITMASK(uint64_t, 0x20000068, 0, 29, 35); *(uint32_t*)0x20000070 = 0; *(uint32_t*)0x20000074 = 0; *(uint64_t*)0x20000078 = -1; *(uint64_t*)0x20000080 = 0; *(uint64_t*)0x20000088 = 0; *(uint64_t*)0x20000090 = 0; *(uint32_t*)0x20000098 = 0; *(uint32_t*)0x2000009c = 0; *(uint64_t*)0x200000a0 = 0; *(uint32_t*)0x200000a8 = 0; *(uint16_t*)0x200000ac = 0; *(uint16_t*)0x200000ae = 0; syscall(__NR_perf_event_open, 0x20000040, 0, 0, -1, 0); break; } } void execute_one() { execute(5); collide = 1; execute(5); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); char* cwd = get_current_dir_name(); for (procid = 0; procid < 8; procid++) { if (fork() == 0) { for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_namespace(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } } } sleep(1000000); return 0; }