// https://syzkaller.appspot.com/bug?id=765cc4b30a90c3561f0743fdaaf96e3e9b1a1ff3 // 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned long long procid; 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 use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } 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 struct { char* pos; int nesting; struct nlattr* nested[8]; char buf[1024]; } nlmsg; static void netlink_init(int typ, int flags, const void* data, int size) { memset(&nlmsg, 0, sizeof(nlmsg)); struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg.buf; hdr->nlmsg_type = typ; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; memcpy(hdr + 1, data, size); nlmsg.pos = (char*)(hdr + 1) + NLMSG_ALIGN(size); } static void netlink_attr(int typ, const void* data, int size) { struct nlattr* attr = (struct nlattr*)nlmsg.pos; attr->nla_len = sizeof(*attr) + size; attr->nla_type = typ; memcpy(attr + 1, data, size); nlmsg.pos += NLMSG_ALIGN(attr->nla_len); } static void netlink_nest(int typ) { struct nlattr* attr = (struct nlattr*)nlmsg.pos; attr->nla_type = typ; nlmsg.pos += sizeof(*attr); nlmsg.nested[nlmsg.nesting++] = attr; } static void netlink_done(void) { struct nlattr* attr = nlmsg.nested[--nlmsg.nesting]; attr->nla_len = nlmsg.pos - (char*)attr; } static int netlink_send(int sock) { if (nlmsg.pos > nlmsg.buf + sizeof(nlmsg.buf) || nlmsg.nesting) exit(1); struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg.buf; hdr->nlmsg_len = nlmsg.pos - nlmsg.buf; struct sockaddr_nl addr; memset(&addr, 0, sizeof(addr)); addr.nl_family = AF_NETLINK; unsigned n = sendto(sock, nlmsg.buf, hdr->nlmsg_len, 0, (struct sockaddr*)&addr, sizeof(addr)); if (n != hdr->nlmsg_len) exit(1); n = recv(sock, nlmsg.buf, sizeof(nlmsg.buf), 0); if (n < sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr)) exit(1); if (hdr->nlmsg_type != NLMSG_ERROR) exit(1); return -((struct nlmsgerr*)(hdr + 1))->error; } static void netlink_add_device_impl(const char* type, const char* name) { struct ifinfomsg hdr; memset(&hdr, 0, sizeof(hdr)); netlink_init(RTM_NEWLINK, NLM_F_EXCL | NLM_F_CREATE, &hdr, sizeof(hdr)); if (name) netlink_attr(IFLA_IFNAME, name, strlen(name)); netlink_nest(IFLA_LINKINFO); netlink_attr(IFLA_INFO_KIND, type, strlen(type)); } static void netlink_add_device(int sock, const char* type, const char* name) { netlink_add_device_impl(type, name); netlink_done(); int err = netlink_send(sock); (void)err; } static void netlink_add_veth(int sock, const char* name, const char* peer) { netlink_add_device_impl("veth", name); netlink_nest(IFLA_INFO_DATA); netlink_nest(VETH_INFO_PEER); nlmsg.pos += sizeof(struct ifinfomsg); netlink_attr(IFLA_IFNAME, peer, strlen(peer)); netlink_done(); netlink_done(); netlink_done(); int err = netlink_send(sock); (void)err; } static void netlink_add_hsr(int sock, const char* name, const char* slave1, const char* slave2) { netlink_add_device_impl("hsr", name); netlink_nest(IFLA_INFO_DATA); int ifindex1 = if_nametoindex(slave1); netlink_attr(IFLA_HSR_SLAVE1, &ifindex1, sizeof(ifindex1)); int ifindex2 = if_nametoindex(slave2); netlink_attr(IFLA_HSR_SLAVE2, &ifindex2, sizeof(ifindex2)); netlink_done(); netlink_done(); int err = netlink_send(sock); (void)err; } static void netlink_device_change(int sock, const char* name, bool up, const char* master, const void* mac, int macsize) { struct ifinfomsg hdr; memset(&hdr, 0, sizeof(hdr)); if (up) hdr.ifi_flags = hdr.ifi_change = IFF_UP; netlink_init(RTM_NEWLINK, 0, &hdr, sizeof(hdr)); netlink_attr(IFLA_IFNAME, name, strlen(name)); if (master) { int ifindex = if_nametoindex(master); netlink_attr(IFLA_MASTER, &ifindex, sizeof(ifindex)); } if (macsize) netlink_attr(IFLA_ADDRESS, mac, macsize); int err = netlink_send(sock); (void)err; } static int netlink_add_addr(int sock, const char* dev, const void* addr, int addrsize) { struct ifaddrmsg hdr; memset(&hdr, 0, sizeof(hdr)); hdr.ifa_family = addrsize == 4 ? AF_INET : AF_INET6; hdr.ifa_prefixlen = addrsize == 4 ? 24 : 120; hdr.ifa_scope = RT_SCOPE_UNIVERSE; hdr.ifa_index = if_nametoindex(dev); netlink_init(RTM_NEWADDR, NLM_F_CREATE | NLM_F_REPLACE, &hdr, sizeof(hdr)); netlink_attr(IFA_LOCAL, addr, addrsize); netlink_attr(IFA_ADDRESS, addr, addrsize); return netlink_send(sock); } static void netlink_add_addr4(int sock, const char* dev, const char* addr) { struct in_addr in_addr; inet_pton(AF_INET, addr, &in_addr); int err = netlink_add_addr(sock, dev, &in_addr, sizeof(in_addr)); (void)err; } static void netlink_add_addr6(int sock, const char* dev, const char* addr) { struct in6_addr in6_addr; inet_pton(AF_INET6, addr, &in6_addr); int err = netlink_add_addr(sock, dev, &in6_addr, sizeof(in6_addr)); (void)err; } static void netlink_add_neigh(int sock, const char* name, const void* addr, int addrsize, const void* mac, int macsize) { struct ndmsg hdr; memset(&hdr, 0, sizeof(hdr)); hdr.ndm_family = addrsize == 4 ? AF_INET : AF_INET6; hdr.ndm_ifindex = if_nametoindex(name); hdr.ndm_state = NUD_PERMANENT; netlink_init(RTM_NEWNEIGH, NLM_F_EXCL | NLM_F_CREATE, &hdr, sizeof(hdr)); netlink_attr(NDA_DST, addr, addrsize); netlink_attr(NDA_LLADDR, mac, macsize); int err = netlink_send(sock); (void)err; } static int tunfd = -1; static int tun_frags_enabled; #define SYZ_TUN_MAX_PACKET_SIZE 1000 #define TUN_IFACE "syz_tun" #define LOCAL_MAC 0xaaaaaaaaaaaa #define REMOTE_MAC 0xaaaaaaaaaabb #define LOCAL_IPV4 "172.20.20.170" #define REMOTE_IPV4 "172.20.20.187" #define LOCAL_IPV6 "fe80::aa" #define REMOTE_IPV6 "fe80::bb" #define IFF_NAPI 0x0010 #define IFF_NAPI_FRAGS 0x0020 static void initialize_tun(void) { 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; } const int kTunFd = 240; if (dup2(tunfd, kTunFd) < 0) exit(1); close(tunfd); tunfd = kTunFd; struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, TUN_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) exit(1); } if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) exit(1); tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0; char sysctl[64]; sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/accept_dad", TUN_IFACE); write_file(sysctl, "0"); sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/router_solicitations", TUN_IFACE); write_file(sysctl, "0"); int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock == -1) exit(1); netlink_add_addr4(sock, TUN_IFACE, LOCAL_IPV4); netlink_add_addr6(sock, TUN_IFACE, LOCAL_IPV6); uint64_t macaddr = REMOTE_MAC; struct in_addr in_addr; inet_pton(AF_INET, REMOTE_IPV4, &in_addr); netlink_add_neigh(sock, TUN_IFACE, &in_addr, sizeof(in_addr), &macaddr, ETH_ALEN); struct in6_addr in6_addr; inet_pton(AF_INET6, REMOTE_IPV6, &in6_addr); netlink_add_neigh(sock, TUN_IFACE, &in6_addr, sizeof(in6_addr), &macaddr, ETH_ALEN); macaddr = LOCAL_MAC; netlink_device_change(sock, TUN_IFACE, true, 0, &macaddr, ETH_ALEN); close(sock); } #define DEV_IPV4 "172.20.20.%d" #define DEV_IPV6 "fe80::%02x" #define DEV_MAC 0x00aaaaaaaaaa static void initialize_netdevices(void) { char netdevsim[16]; sprintf(netdevsim, "netdevsim%d", (int)procid); struct { const char* type; const char* dev; } devtypes[] = { {"ip6gretap", "ip6gretap0"}, {"bridge", "bridge0"}, {"vcan", "vcan0"}, {"bond", "bond0"}, {"team", "team0"}, {"dummy", "dummy0"}, {"nlmon", "nlmon0"}, {"caif", "caif0"}, {"batadv", "batadv0"}, {"vxcan", "vxcan1"}, {"netdevsim", netdevsim}, {"veth", 0}, }; const char* devmasters[] = {"bridge", "bond", "team"}; struct { const char* name; int macsize; bool noipv6; } devices[] = { {"lo", ETH_ALEN}, {"sit0", 0}, {"bridge0", ETH_ALEN}, {"vcan0", 0, true}, {"tunl0", 0}, {"gre0", 0}, {"gretap0", ETH_ALEN}, {"ip_vti0", 0}, {"ip6_vti0", 0}, {"ip6tnl0", 0}, {"ip6gre0", 0}, {"ip6gretap0", ETH_ALEN}, {"erspan0", ETH_ALEN}, {"bond0", ETH_ALEN}, {"veth0", ETH_ALEN}, {"veth1", ETH_ALEN}, {"team0", ETH_ALEN}, {"veth0_to_bridge", ETH_ALEN}, {"veth1_to_bridge", ETH_ALEN}, {"veth0_to_bond", ETH_ALEN}, {"veth1_to_bond", ETH_ALEN}, {"veth0_to_team", ETH_ALEN}, {"veth1_to_team", ETH_ALEN}, {"veth0_to_hsr", ETH_ALEN}, {"veth1_to_hsr", ETH_ALEN}, {"hsr0", 0}, {"dummy0", ETH_ALEN}, {"nlmon0", 0}, {"vxcan1", 0, true}, {"caif0", ETH_ALEN}, {"batadv0", ETH_ALEN}, {netdevsim, ETH_ALEN}, }; int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock == -1) exit(1); unsigned i; for (i = 0; i < sizeof(devtypes) / sizeof(devtypes[0]); i++) netlink_add_device(sock, devtypes[i].type, devtypes[i].dev); for (i = 0; i < sizeof(devmasters) / (sizeof(devmasters[0])); i++) { char master[32], slave0[32], veth0[32], slave1[32], veth1[32]; sprintf(slave0, "%s_slave_0", devmasters[i]); sprintf(veth0, "veth0_to_%s", devmasters[i]); netlink_add_veth(sock, slave0, veth0); sprintf(slave1, "%s_slave_1", devmasters[i]); sprintf(veth1, "veth1_to_%s", devmasters[i]); netlink_add_veth(sock, slave1, veth1); sprintf(master, "%s0", devmasters[i]); netlink_device_change(sock, slave0, false, master, 0, 0); netlink_device_change(sock, slave1, false, master, 0, 0); } netlink_device_change(sock, "bridge_slave_0", true, 0, 0, 0); netlink_device_change(sock, "bridge_slave_1", true, 0, 0, 0); netlink_add_veth(sock, "hsr_slave_0", "veth0_to_hsr"); netlink_add_veth(sock, "hsr_slave_1", "veth1_to_hsr"); netlink_add_hsr(sock, "hsr0", "hsr_slave_0", "hsr_slave_1"); netlink_device_change(sock, "hsr_slave_0", true, 0, 0, 0); netlink_device_change(sock, "hsr_slave_1", true, 0, 0, 0); for (i = 0; i < sizeof(devices) / (sizeof(devices[0])); i++) { char addr[32]; sprintf(addr, DEV_IPV4, i + 10); netlink_add_addr4(sock, devices[i].name, addr); if (!devices[i].noipv6) { sprintf(addr, DEV_IPV6, i + 10); netlink_add_addr6(sock, devices[i].name, addr); } uint64_t macaddr = DEV_MAC + ((i + 10ull) << 40); netlink_device_change(sock, devices[i].name, true, 0, &macaddr, devices[i].macsize); } close(sock); } static void initialize_netdevices_init(void) { int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock == -1) exit(1); struct { const char* type; int macsize; bool noipv6; bool noup; } devtypes[] = { {"nr", 7, true}, {"rose", 5, true, true}, }; unsigned i; for (i = 0; i < sizeof(devtypes) / sizeof(devtypes[0]); i++) { char dev[32], addr[32]; sprintf(dev, "%s%d", devtypes[i].type, (int)procid); sprintf(addr, "172.30.%d.%d", i, (int)procid + 1); netlink_add_addr4(sock, dev, addr); if (!devtypes[i].noipv6) { sprintf(addr, "fe88::%02x:%02x", i, (int)procid + 1); netlink_add_addr6(sock, dev, addr); } int macsize = devtypes[i].macsize; uint64_t macaddr = 0xbbbbbb + ((unsigned long long)i << (8 * (macsize - 2))) + (procid << (8 * (macsize - 1))); netlink_device_change(sock, dev, !devtypes[i].noup, 0, &macaddr, macsize); } close(sock); } 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; exit(1); } return rv; } static void flush_tun() { char data[SYZ_TUN_MAX_PACKET_SIZE]; while (read_tun(&data[0], sizeof(data)) != -1) { } } #define MAX_FDS 30 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(); initialize_netdevices_init(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); exit(1); } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: while (umount2(dir, MNT_DETACH) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } 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); while (umount2(filename, MNT_DETACH) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, MNT_DETACH)) exit(1); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } static int inject_fault(int nth) { int fd; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exit(1); char buf[16]; sprintf(buf, "%d", nth + 1); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exit(1); return fd; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); int i; for (i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); flush_tun(); } static void close_fds() { int fd; for (fd = 3; fd < MAX_FDS; fd++) close(fd); } static void setup_fault() { static struct { const char* file; const char* val; bool fatal; } files[] = { {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true}, {"/sys/kernel/debug/fail_futex/ignore-private", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false}, {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false}, }; unsigned i; for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].file, files[i].val)) { if (files[i].fatal) exit(1); } } } static void setup_binfmt_misc() { if (mount(0, "/proc/sys/fs/binfmt_misc", "binfmt_misc", 0, 0)) { } write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:\x01::./file0:"); write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:\x02::./file0:POC"); } 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 execute_one(void) { int i, call, thread; int collide = 0; again: for (call = 0; call < 7; 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; } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter; for (iter = 0;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5 * 1000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0x0}; void execute_call(int call) { intptr_t res; switch (call) { case 0: res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[0] = res; break; case 1: res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[1] = res; break; case 2: res = syscall(__NR_socket, 0x10, 0x803, 0); if (res != -1) r[2] = res; break; case 3: NONFAILING(*(uint64_t*)0x200001c0 = 0); NONFAILING(*(uint32_t*)0x200001c8 = 0); NONFAILING(*(uint64_t*)0x200001d0 = 0x20000180); NONFAILING(*(uint64_t*)0x20000180 = 0); NONFAILING(*(uint64_t*)0x20000188 = 0); NONFAILING(*(uint64_t*)0x200001d8 = 1); NONFAILING(*(uint64_t*)0x200001e0 = 0); NONFAILING(*(uint64_t*)0x200001e8 = 0); NONFAILING(*(uint32_t*)0x200001f0 = 0); syscall(__NR_sendmsg, r[2], 0x200001c0, 0); break; case 4: NONFAILING(*(uint32_t*)0x20000200 = 0x14); res = syscall(__NR_getsockname, r[2], 0x20000100, 0x20000200); if (res != -1) NONFAILING(r[3] = *(uint32_t*)0x20000104); break; case 5: syscall(__NR_sendmsg, r[1], 0, 0); break; case 6: NONFAILING(*(uint64_t*)0x20000080 = 0); NONFAILING(*(uint32_t*)0x20000088 = 0x300); NONFAILING(*(uint64_t*)0x20000090 = 0x20000040); NONFAILING(*(uint64_t*)0x20000040 = 0x200000c0); NONFAILING(*(uint32_t*)0x200000c0 = 0x28); NONFAILING(*(uint16_t*)0x200000c4 = 0x10); NONFAILING(*(uint16_t*)0x200000c6 = 0x825); NONFAILING(*(uint32_t*)0x200000c8 = 0); NONFAILING(*(uint32_t*)0x200000cc = 0); NONFAILING(*(uint8_t*)0x200000d0 = 0); NONFAILING(*(uint8_t*)0x200000d1 = 0); NONFAILING(*(uint16_t*)0x200000d2 = 0); NONFAILING(*(uint32_t*)0x200000d4 = r[3]); NONFAILING(*(uint32_t*)0x200000d8 = 0); NONFAILING(*(uint32_t*)0x200000dc = 0); NONFAILING(*(uint16_t*)0x200000e0 = 8); NONFAILING(*(uint16_t*)0x200000e2 = 0xa); NONFAILING(*(uint8_t*)0x200000e4 = 0x14); NONFAILING(*(uint64_t*)0x20000048 = 0x28); NONFAILING(*(uint64_t*)0x20000098 = 1); NONFAILING(*(uint64_t*)0x200000a0 = 0); NONFAILING(*(uint64_t*)0x200000a8 = 0); NONFAILING(*(uint32_t*)0x200000b0 = 0); inject_fault(10); syscall(__NR_sendmsg, r[0], 0x20000080, 0); break; } } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); setup_binfmt_misc(); setup_fault(); install_segv_handler(); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { use_temporary_dir(); do_sandbox_none(); } } sleep(1000000); return 0; }