// https://syzkaller.appspot.com/bug?id=61ec9b78979c77b478704a46b43300223433acfe // 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 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 __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* uctx) { 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); } doexit(sig); } static void install_segv_handler() { 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 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 uintptr_t syz_open_procfs(uintptr_t a0, uintptr_t a1) { char buf[128]; memset(buf, 0, sizeof(buf)); if (a0 == 0) { NONFAILING(snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1)); } else if (a0 == (uintptr_t)-1) { NONFAILING(snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1)); } else { NONFAILING(snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0, (char*)a1)); } int fd = open(buf, O_RDWR); if (fd == -1) fd = open(buf, O_RDONLY); return fd; } 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 if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(CLONE_NEWCGROUP)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } static int do_sandbox_none(int executor_pid, bool enable_tun) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } #define XT_TABLE_SIZE 1536 #define XT_MAX_ENTRIES 10 struct xt_counters { uint64_t pcnt, bcnt; }; struct ipt_getinfo { char name[32]; unsigned int valid_hooks; unsigned int hook_entry[5]; unsigned int underflow[5]; unsigned int num_entries; unsigned int size; }; struct ipt_get_entries { char name[32]; unsigned int size; void* entrytable[XT_TABLE_SIZE / sizeof(void*)]; }; struct ipt_replace { char name[32]; unsigned int valid_hooks; unsigned int num_entries; unsigned int size; unsigned int hook_entry[5]; unsigned int underflow[5]; unsigned int num_counters; struct xt_counters* counters; char entrytable[XT_TABLE_SIZE]; }; struct ipt_table_desc { const char* name; struct ipt_getinfo info; struct ipt_replace replace; }; static struct ipt_table_desc ipv4_tables[] = { {.name = "filter"}, {.name = "nat"}, {.name = "mangle"}, {.name = "raw"}, {.name = "security"}, }; static struct ipt_table_desc ipv6_tables[] = { {.name = "filter"}, {.name = "nat"}, {.name = "mangle"}, {.name = "raw"}, {.name = "security"}, }; #define IPT_BASE_CTL 64 #define IPT_SO_SET_REPLACE (IPT_BASE_CTL) #define IPT_SO_GET_INFO (IPT_BASE_CTL) #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1) struct arpt_getinfo { char name[32]; unsigned int valid_hooks; unsigned int hook_entry[3]; unsigned int underflow[3]; unsigned int num_entries; unsigned int size; }; struct arpt_get_entries { char name[32]; unsigned int size; void* entrytable[XT_TABLE_SIZE / sizeof(void*)]; }; struct arpt_replace { char name[32]; unsigned int valid_hooks; unsigned int num_entries; unsigned int size; unsigned int hook_entry[3]; unsigned int underflow[3]; unsigned int num_counters; struct xt_counters* counters; char entrytable[XT_TABLE_SIZE]; }; struct arpt_table_desc { const char* name; struct arpt_getinfo info; struct arpt_replace replace; }; static struct arpt_table_desc arpt_tables[] = { {.name = "filter"}, }; #define ARPT_BASE_CTL 96 #define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL) #define ARPT_SO_GET_INFO (ARPT_BASE_CTL) #define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1) static void checkpoint_iptables(struct ipt_table_desc* tables, int num_tables, int family, int level) { struct ipt_get_entries entries; socklen_t optlen; int fd, i; fd = socket(family, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family); for (i = 0; i < num_tables; i++) { struct ipt_table_desc* table = &tables[i]; strcpy(table->info.name, table->name); strcpy(table->replace.name, table->name); optlen = sizeof(table->info); if (getsockopt(fd, level, IPT_SO_GET_INFO, &table->info, &optlen)) { switch (errno) { case EPERM: case ENOENT: case ENOPROTOOPT: continue; } fail("getsockopt(IPT_SO_GET_INFO)"); } if (table->info.size > sizeof(table->replace.entrytable)) fail("table size is too large: %u", table->info.size); if (table->info.num_entries > XT_MAX_ENTRIES) fail("too many counters: %u", table->info.num_entries); memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size; if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(IPT_SO_GET_ENTRIES)"); table->replace.valid_hooks = table->info.valid_hooks; table->replace.num_entries = table->info.num_entries; table->replace.size = table->info.size; memcpy(table->replace.hook_entry, table->info.hook_entry, sizeof(table->replace.hook_entry)); memcpy(table->replace.underflow, table->info.underflow, sizeof(table->replace.underflow)); memcpy(table->replace.entrytable, entries.entrytable, table->info.size); } close(fd); } static void reset_iptables(struct ipt_table_desc* tables, int num_tables, int family, int level) { struct xt_counters counters[XT_MAX_ENTRIES]; struct ipt_get_entries entries; struct ipt_getinfo info; socklen_t optlen; int fd, i; fd = socket(family, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family); for (i = 0; i < num_tables; i++) { struct ipt_table_desc* table = &tables[i]; if (table->info.valid_hooks == 0) continue; memset(&info, 0, sizeof(info)); strcpy(info.name, table->name); optlen = sizeof(info); if (getsockopt(fd, level, IPT_SO_GET_INFO, &info, &optlen)) fail("getsockopt(IPT_SO_GET_INFO)"); if (memcmp(&table->info, &info, sizeof(table->info)) == 0) { memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size; if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(IPT_SO_GET_ENTRIES)"); if (memcmp(table->replace.entrytable, entries.entrytable, table->info.size) == 0) continue; } table->replace.num_counters = info.num_entries; table->replace.counters = counters; optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) + table->replace.size; if (setsockopt(fd, level, IPT_SO_SET_REPLACE, &table->replace, optlen)) fail("setsockopt(IPT_SO_SET_REPLACE)"); } close(fd); } static void checkpoint_arptables(void) { struct arpt_get_entries entries; socklen_t optlen; unsigned i; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) { struct arpt_table_desc* table = &arpt_tables[i]; strcpy(table->info.name, table->name); strcpy(table->replace.name, table->name); optlen = sizeof(table->info); if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &table->info, &optlen)) { switch (errno) { case EPERM: case ENOENT: case ENOPROTOOPT: continue; } fail("getsockopt(ARPT_SO_GET_INFO)"); } if (table->info.size > sizeof(table->replace.entrytable)) fail("table size is too large: %u", table->info.size); if (table->info.num_entries > XT_MAX_ENTRIES) fail("too many counters: %u", table->info.num_entries); memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size; if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(ARPT_SO_GET_ENTRIES)"); table->replace.valid_hooks = table->info.valid_hooks; table->replace.num_entries = table->info.num_entries; table->replace.size = table->info.size; memcpy(table->replace.hook_entry, table->info.hook_entry, sizeof(table->replace.hook_entry)); memcpy(table->replace.underflow, table->info.underflow, sizeof(table->replace.underflow)); memcpy(table->replace.entrytable, entries.entrytable, table->info.size); } close(fd); } static void reset_arptables() { struct xt_counters counters[XT_MAX_ENTRIES]; struct arpt_get_entries entries; struct arpt_getinfo info; socklen_t optlen; unsigned i; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) { struct arpt_table_desc* table = &arpt_tables[i]; if (table->info.valid_hooks == 0) continue; memset(&info, 0, sizeof(info)); strcpy(info.name, table->name); optlen = sizeof(info); if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &info, &optlen)) fail("getsockopt(ARPT_SO_GET_INFO)"); if (memcmp(&table->info, &info, sizeof(table->info)) == 0) { memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size; if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(ARPT_SO_GET_ENTRIES)"); if (memcmp(table->replace.entrytable, entries.entrytable, table->info.size) == 0) continue; } table->replace.num_counters = info.num_entries; table->replace.counters = counters; optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) + table->replace.size; if (setsockopt(fd, SOL_IP, ARPT_SO_SET_REPLACE, &table->replace, optlen)) fail("setsockopt(ARPT_SO_SET_REPLACE)"); } close(fd); } #include #include struct ebt_table_desc { const char* name; struct ebt_replace replace; char entrytable[XT_TABLE_SIZE]; }; static struct ebt_table_desc ebt_tables[] = { {.name = "filter"}, {.name = "nat"}, {.name = "broute"}, }; static void checkpoint_ebtables(void) { socklen_t optlen; unsigned i; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) { struct ebt_table_desc* table = &ebt_tables[i]; strcpy(table->replace.name, table->name); optlen = sizeof(table->replace); if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_INFO, &table->replace, &optlen)) { switch (errno) { case EPERM: case ENOENT: case ENOPROTOOPT: continue; } fail("getsockopt(EBT_SO_GET_INIT_INFO)"); } if (table->replace.entries_size > sizeof(table->entrytable)) fail("table size is too large: %u", table->replace.entries_size); table->replace.num_counters = 0; table->replace.entries = table->entrytable; optlen = sizeof(table->replace) + table->replace.entries_size; if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_ENTRIES, &table->replace, &optlen)) fail("getsockopt(EBT_SO_GET_INIT_ENTRIES)"); } close(fd); } static void reset_ebtables() { struct ebt_replace replace; char entrytable[XT_TABLE_SIZE]; socklen_t optlen; unsigned i, j, h; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) { struct ebt_table_desc* table = &ebt_tables[i]; if (table->replace.valid_hooks == 0) continue; memset(&replace, 0, sizeof(replace)); strcpy(replace.name, table->name); optlen = sizeof(replace); if (getsockopt(fd, SOL_IP, EBT_SO_GET_INFO, &replace, &optlen)) fail("getsockopt(EBT_SO_GET_INFO)"); replace.num_counters = 0; for (h = 0; h < NF_BR_NUMHOOKS; h++) table->replace.hook_entry[h] = 0; if (memcmp(&table->replace, &replace, sizeof(table->replace)) == 0) { memset(&entrytable, 0, sizeof(entrytable)); replace.entries = entrytable; optlen = sizeof(replace) + replace.entries_size; if (getsockopt(fd, SOL_IP, EBT_SO_GET_ENTRIES, &replace, &optlen)) fail("getsockopt(EBT_SO_GET_ENTRIES)"); if (memcmp(table->entrytable, entrytable, replace.entries_size) == 0) continue; } for (j = 0, h = 0; h < NF_BR_NUMHOOKS; h++) { if (table->replace.valid_hooks & (1 << h)) { table->replace.hook_entry[h] = (struct ebt_entries*)table->entrytable + j; j++; } } optlen = sizeof(table->replace) + table->replace.entries_size; if (setsockopt(fd, SOL_IP, EBT_SO_SET_ENTRIES, &table->replace, optlen)) fail("setsockopt(EBT_SO_SET_ENTRIES)"); } close(fd); } static void checkpoint_net_namespace(void) { checkpoint_ebtables(); checkpoint_arptables(); checkpoint_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]), AF_INET, SOL_IP); checkpoint_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]), AF_INET6, SOL_IPV6); } static void reset_net_namespace(void) { reset_ebtables(); reset_arptables(); reset_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]), AF_INET, SOL_IP); reset_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]), AF_INET6, SOL_IPV6); } static void test(); void loop() { int iter; checkpoint_net_namespace(); for (iter = 0;; iter++) { int pid = fork(); if (pid < 0) fail("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); 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; } } reset_net_namespace(); } } 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; } } } } long r[1]; uint64_t procid; void execute_call(int call) { switch (call) { case 0: syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); break; case 1: syscall(__NR_clone, 0x200, 0x20611000, 0x20744000, 0x20f8b000, 0x20b40000); break; case 2: NONFAILING(memcpy((void*)0x20f80000, "./file0", 8)); syscall(__NR_mknod, 0x20f80000, 0x1040, 0); break; case 3: NONFAILING(memcpy((void*)0x202a7000, "./file0", 8)); syscall(__NR_execve, 0x202a7000, 0x207a9000, 0x206fcff0); break; case 4: NONFAILING(memcpy((void*)0x20d9e000, "stack", 6)); r[0] = syz_open_procfs(0, 0x20d9e000); break; case 5: syscall(__NR_read, r[0], 0x201edff8, 8); break; } } void test() { memset(r, -1, sizeof(r)); execute(6); collide = 1; execute(6); } int main() { for (procid = 0; procid < 8; procid++) { if (fork() == 0) { install_segv_handler(); for (;;) { int pid = do_sandbox_none(procid, false); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } } } sleep(1000000); return 0; }