// https://syzkaller.appspot.com/bug?id=3c1f47967b7cbd399d3ba3e65f297a29aa1c5f92 // 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 #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; \ } struct csum_inet { uint32_t acc; }; static void csum_inet_init(struct csum_inet* csum) { csum->acc = 0; } static void csum_inet_update(struct csum_inet* csum, const uint8_t* data, size_t length) { if (length == 0) return; size_t i; for (i = 0; i < length - 1; i += 2) csum->acc += *(uint16_t*)&data[i]; if (length & 1) csum->acc += (uint16_t)data[length - 1]; while (csum->acc > 0xffff) csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16); } static uint16_t csum_inet_digest(struct csum_inet* csum) { return ~csum->acc; } static uint64_t current_time_ms() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } 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 void vsnprintf_check(char* str, size_t size, const char* format, va_list args) { int rv; rv = vsnprintf(str, size, format, args); if (rv < 0) fail("tun: snprintf failed"); if ((size_t)rv >= size) fail("tun: string '%s...' doesn't fit into buffer", str); } static void snprintf_check(char* str, size_t size, const char* format, ...) { va_list args; va_start(args, format); vsnprintf_check(str, size, format, args); va_end(args); } #define COMMAND_MAX_LEN 128 #define PATH_PREFIX \ "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin " #define PATH_PREFIX_LEN (sizeof(PATH_PREFIX) - 1) static void execute_command(const char* format, ...) { va_list args; char command[PATH_PREFIX_LEN + COMMAND_MAX_LEN]; int rv; va_start(args, format); memcpy(command, PATH_PREFIX, PATH_PREFIX_LEN); vsnprintf_check(command + PATH_PREFIX_LEN, COMMAND_MAX_LEN, format, args); rv = system(command); if (rv != 0) fail("tun: command \"%s\" failed with code %d", &command[0], rv); va_end(args); } static int tunfd = -1; static int tun_frags_enabled; #define SYZ_TUN_MAX_PACKET_SIZE 1000 #define MAX_PIDS 32 #define ADDR_MAX_LEN 32 #define LOCAL_MAC "aa:aa:aa:aa:aa:%02hx" #define REMOTE_MAC "bb:bb:bb:bb:bb:%02hx" #define LOCAL_IPV4 "172.20.%d.170" #define REMOTE_IPV4 "172.20.%d.187" #define LOCAL_IPV6 "fe80::%02hxaa" #define REMOTE_IPV6 "fe80::%02hxbb" #define IFF_NAPI 0x0010 #define IFF_NAPI_FRAGS 0x0020 static void initialize_tun(uint64_t pid) { if (pid >= MAX_PIDS) fail("tun: no more than %d executors", MAX_PIDS); int id = pid; tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK); if (tunfd == -1) { printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n"); printf("otherwise fuzzing or reproducing might not work as intended\n"); return; } char iface[IFNAMSIZ]; snprintf_check(iface, sizeof(iface), "syz%d", id); struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, iface, IFNAMSIZ); ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS; if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) { ifr.ifr_flags = IFF_TAP | IFF_NO_PI; if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) fail("tun: ioctl(TUNSETIFF) failed"); } if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) fail("tun: ioctl(TUNGETIFF) failed"); tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0; char local_mac[ADDR_MAX_LEN]; snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id); char remote_mac[ADDR_MAX_LEN]; snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id); char local_ipv4[ADDR_MAX_LEN]; snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id); char remote_ipv4[ADDR_MAX_LEN]; snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id); char local_ipv6[ADDR_MAX_LEN]; snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id); char remote_ipv6[ADDR_MAX_LEN]; snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id); execute_command("sysctl -w net.ipv6.conf.%s.accept_dad=0", iface); execute_command("sysctl -w net.ipv6.conf.%s.router_solicitations=0", iface); execute_command("ip link set dev %s address %s", iface, local_mac); execute_command("ip addr add %s/24 dev %s", local_ipv4, iface); execute_command("ip -6 addr add %s/120 dev %s", local_ipv6, iface); execute_command("ip neigh add %s lladdr %s dev %s nud permanent", remote_ipv4, remote_mac, iface); execute_command("ip -6 neigh add %s lladdr %s dev %s nud permanent", remote_ipv6, remote_mac, iface); execute_command("ip link set dev %s up", iface); } static void setup_tun(uint64_t pid, bool enable_tun) { if (enable_tun) initialize_tun(pid); } static int read_tun(char* data, int size) { if (tunfd < 0) return -1; int rv = read(tunfd, data, size); if (rv < 0) { if (errno == EAGAIN) return -1; if (errno == EBADFD) return -1; fail("tun: read failed with %d", rv); } return rv; } static void flush_tun() { char data[SYZ_TUN_MAX_PACKET_SIZE]; while (read_tun(&data[0], sizeof(data)) != -1) ; } 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 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 = 1 << 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); #define CLONE_NEWCGROUP 0x02000000 unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_NEWCGROUP); unshare(CLONE_NEWNET); unshare(CLONE_NEWUTS); unshare(CLONE_SYSVSEM); } 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) { close(fd); return false; } close(fd); return true; } 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 (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"); if (mount("/dev", "./syz-tmp/newroot/dev", NULL, MS_BIND | MS_REC | MS_PRIVATE, 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/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(int executor_pid, bool enable_tun) { int pid; setup_tun(executor_pid, enable_tun); 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, NULL); if (pid < 0) fail("sandbox clone failed"); return pid; } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting", dir); } exitf("opendir(%s) failed", dir); } while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); struct stat st; if (lstat(filename, &st)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } } static void test(); void loop() { int iter; for (iter = 0;; iter++) { char cwdbuf[256]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); flush_tun(); test(); doexit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(-1, &status, __WALL | WNOHANG); if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } } remove_dir(cwdbuf); } } #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_write #define __NR_write 4 #endif #ifndef __NR_readv #define __NR_readv 145 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 long r[1]; void test() { memset(r, -1, sizeof(r)); syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); memcpy((void*)0x208c8000, "/dev/sg#", 9); r[0] = syz_open_dev(0x208c8000, 0, 0x8002); *(uint8_t*)0x20ace000 = 2; *(uint8_t*)0x20ace001 = 0x83; *(uint16_t*)0x20ace002 = 0xfcc; *(uint16_t*)0x20ace004 = 1; *(uint16_t*)0x20ace006 = 4; *(uint16_t*)0x20ace008 = -1; STORE_BY_BITMASK(uint8_t, 0x20ace00a, 0x1e, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20ace00a, 4, 4, 4); STORE_BY_BITMASK(uint8_t, 0x20ace00b, 1, 0, 2); STORE_BY_BITMASK(uint8_t, 0x20ace00b, 7, 2, 6); *(uint16_t*)0x20ace00c = htobe16(0x88); *(uint16_t*)0x20ace00e = htobe16(0x67); *(uint16_t*)0x20ace010 = htobe16(0); *(uint8_t*)0x20ace012 = 0x86; *(uint8_t*)0x20ace013 = 0x6e; *(uint16_t*)0x20ace014 = 0; *(uint8_t*)0x20ace016 = 0xac; *(uint8_t*)0x20ace017 = 0x14; *(uint8_t*)0x20ace018 = 0; *(uint8_t*)0x20ace019 = 0xbb; *(uint32_t*)0x20ace01a = htobe32(0); *(uint8_t*)0x20ace01e = 0x89; *(uint8_t*)0x20ace01f = 0x2b; *(uint8_t*)0x20ace020 = 0x1f; *(uint32_t*)0x20ace021 = htobe32(0xe0000001); *(uint32_t*)0x20ace025 = htobe32(0xe0000002); *(uint32_t*)0x20ace029 = htobe32(5); *(uint32_t*)0x20ace02d = htobe32(0xe0000002); *(uint8_t*)0x20ace031 = 0xac; *(uint8_t*)0x20ace032 = 0x14; *(uint8_t*)0x20ace033 = 0; *(uint8_t*)0x20ace034 = 0xbb; *(uint32_t*)0x20ace035 = htobe32(0); *(uint32_t*)0x20ace039 = htobe32(0x7f000001); *(uint32_t*)0x20ace03d = htobe32(0x7ff); *(uint32_t*)0x20ace041 = htobe32(0); *(uint32_t*)0x20ace045 = htobe32(0xe0000002); *(uint8_t*)0x20ace049 = 0x86; *(uint8_t*)0x20ace04a = 0x10; *(uint32_t*)0x20ace04b = htobe32(0x1f); *(uint8_t*)0x20ace04f = 0; *(uint8_t*)0x20ace050 = 2; *(uint8_t*)0x20ace051 = 5; *(uint8_t*)0x20ace052 = 2; *(uint8_t*)0x20ace053 = 0; *(uint8_t*)0x20ace054 = 2; *(uint8_t*)0x20ace055 = 0; *(uint8_t*)0x20ace056 = 2; *(uint8_t*)0x20ace057 = 7; *(uint8_t*)0x20ace058 = 2; *(uint8_t*)0x20ace059 = 7; *(uint8_t*)0x20ace05a = 0x27; *(uint8_t*)0x20ace05b = 5; *(uint8_t*)0x20ace05c = 0xac; *(uint8_t*)0x20ace05d = 0x14; *(uint8_t*)0x20ace05e = 0; *(uint8_t*)0x20ace05f = 0xbb; *(uint32_t*)0x20ace060 = htobe32(0x7f000001); *(uint32_t*)0x20ace064 = htobe32(0); *(uint8_t*)0x20ace068 = 0xac; *(uint8_t*)0x20ace069 = 0x14; *(uint8_t*)0x20ace06a = 0; *(uint8_t*)0x20ace06b = 0xbb; *(uint32_t*)0x20ace06c = htobe32(0x7f000001); *(uint32_t*)0x20ace070 = htobe32(-1); *(uint32_t*)0x20ace074 = htobe32(0x7f000001); *(uint32_t*)0x20ace078 = htobe32(9); *(uint32_t*)0x20ace07c = htobe32(0x3f); *(uint16_t*)0x20ace082 = htobe16(0x4e23); *(uint16_t*)0x20ace084 = htobe16(0x4e21); *(uint8_t*)0x20ace086 = 4; STORE_BY_BITMASK(uint8_t, 0x20ace087, 1, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20ace087, 0x52, 4, 4); *(uint16_t*)0x20ace088 = 0; STORE_BY_BITMASK(uint8_t, 0x20ace08a, 0, 0, 1); STORE_BY_BITMASK(uint8_t, 0x20ace08a, 0, 1, 4); STORE_BY_BITMASK(uint8_t, 0x20ace08a, 0xce, 5, 3); memcpy((void*)0x20ace08b, "\x77\xfd\x93", 3); *(uint8_t*)0x20ace08e = 6; memcpy((void*)0x20ace08f, "\x41\x9e\x5f", 3); struct csum_inet csum_1; csum_inet_init(&csum_1); csum_inet_update(&csum_1, (const uint8_t*)0x20ace016, 4); csum_inet_update(&csum_1, (const uint8_t*)0x20ace01a, 4); uint16_t csum_1_chunk_2 = 0x2100; csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 2); uint16_t csum_1_chunk_3 = 0x1000; csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 2); csum_inet_update(&csum_1, (const uint8_t*)0x20ace082, 16); *(uint16_t*)0x20ace088 = csum_inet_digest(&csum_1); struct csum_inet csum_2; csum_inet_init(&csum_2); csum_inet_update(&csum_2, (const uint8_t*)0x20ace00a, 120); *(uint16_t*)0x20ace014 = csum_inet_digest(&csum_2); syscall(__NR_write, r[0], 0x20ace000, 0x92); *(uint32_t*)0x204f2000 = 0x207bc000; *(uint32_t*)0x204f2004 = 0; *(uint32_t*)0x204f2008 = 0x20180000; *(uint32_t*)0x204f200c = 0; *(uint32_t*)0x204f2010 = 0x20035f1b; *(uint32_t*)0x204f2014 = 0; *(uint32_t*)0x204f2018 = 0x20523f39; *(uint32_t*)0x204f201c = 0; *(uint32_t*)0x204f2020 = 0x203daf4b; *(uint32_t*)0x204f2024 = 0; *(uint32_t*)0x204f2028 = 0x20fa5000; *(uint32_t*)0x204f202c = 0; *(uint32_t*)0x204f2030 = 0x20729000; *(uint32_t*)0x204f2034 = 0; *(uint32_t*)0x204f2038 = 0x2041fff8; *(uint32_t*)0x204f203c = 0; *(uint32_t*)0x204f2040 = 0x20982000; *(uint32_t*)0x204f2044 = 0; *(uint32_t*)0x204f2048 = 0x20142000; *(uint32_t*)0x204f204c = 1; syscall(__NR_readv, r[0], 0x204f2000, 0xa); } int main() { char* cwd = get_current_dir_name(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_namespace(0, true); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } }