// https://syzkaller.appspot.com/bug?id=8a18efe79140782a88dcd098808d6ab20ed740cc // 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 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; } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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; } #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); } static 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(); if (unshare(CLONE_NEWNET)) { } loop(); exit(1); } 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"); } static void close_fds() { int fd; for (fd = 3; fd < MAX_FDS; fd++) close(fd); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter; for (iter = 0;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); execute_one(); close_fds(); 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; } } } uint64_t r[6] = {0xffffffffffffffff, 0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0xffffffffffffffff, 0x0}; void execute_one(void) { intptr_t res = 0; res = syscall(__NR_socket, 0x10ul, 3ul, 0); if (res != -1) r[0] = res; res = syscall(__NR_socket, 0x10ul, 0x803ul, 0); if (res != -1) r[1] = res; 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[1], 0x200001c0ul, 0ul); NONFAILING(*(uint32_t*)0x20000200 = 0x14); res = syscall(__NR_getsockname, r[1], 0x20000100ul, 0x20000200ul); if (res != -1) NONFAILING(r[2] = *(uint32_t*)0x20000104); res = syscall(__NR_socket, 0x10ul, 3ul, 0); if (res != -1) r[3] = res; res = syscall(__NR_socket, 1ul, 0x803ul, 0); if (res != -1) r[4] = res; NONFAILING(*(uint32_t*)0x200002c0 = 0x14); res = syscall(__NR_getsockname, r[4], 0x20000100ul, 0x200002c0ul); if (res != -1) NONFAILING(r[5] = *(uint32_t*)0x20000104); NONFAILING(*(uint64_t*)0x20000080 = 0); NONFAILING(*(uint32_t*)0x20000088 = 0); NONFAILING(*(uint64_t*)0x20000090 = 0x20000140); NONFAILING(*(uint64_t*)0x20000140 = 0x20000300); NONFAILING(*(uint32_t*)0x20000300 = 0x3c); NONFAILING(*(uint16_t*)0x20000304 = 0x10); NONFAILING(*(uint16_t*)0x20000306 = 0x401); NONFAILING(*(uint32_t*)0x20000308 = 0); NONFAILING(*(uint32_t*)0x2000030c = 0); NONFAILING(*(uint8_t*)0x20000310 = 0); NONFAILING(*(uint8_t*)0x20000311 = 0); NONFAILING(*(uint16_t*)0x20000312 = 0); NONFAILING(*(uint32_t*)0x20000314 = 0); NONFAILING(*(uint32_t*)0x20000318 = 0); NONFAILING(*(uint32_t*)0x2000031c = 0); NONFAILING(*(uint16_t*)0x20000320 = 0x14); NONFAILING(STORE_BY_BITMASK(uint16_t, , 0x20000322, 0x12, 0, 14)); NONFAILING(STORE_BY_BITMASK(uint16_t, , 0x20000323, 0, 6, 1)); NONFAILING(STORE_BY_BITMASK(uint16_t, , 0x20000323, 1, 7, 1)); NONFAILING(*(uint16_t*)0x20000324 = 0xb); NONFAILING(*(uint16_t*)0x20000326 = 1); NONFAILING(memcpy((void*)0x20000328, "ipvlan\000", 7)); NONFAILING(*(uint16_t*)0x20000330 = 4); NONFAILING(STORE_BY_BITMASK(uint16_t, , 0x20000332, 2, 0, 14)); NONFAILING(STORE_BY_BITMASK(uint16_t, , 0x20000333, 0, 6, 1)); NONFAILING(STORE_BY_BITMASK(uint16_t, , 0x20000333, 1, 7, 1)); NONFAILING(*(uint16_t*)0x20000334 = 8); NONFAILING(*(uint16_t*)0x20000336 = 5); NONFAILING(*(uint32_t*)0x20000338 = r[5]); NONFAILING(*(uint64_t*)0x20000148 = 0x3c); NONFAILING(*(uint64_t*)0x20000098 = 1); NONFAILING(*(uint64_t*)0x200000a0 = 0); NONFAILING(*(uint64_t*)0x200000a8 = 0); NONFAILING(*(uint32_t*)0x200000b0 = 0); syscall(__NR_sendmsg, r[3], 0x20000080ul, 0ul); NONFAILING(*(uint64_t*)0x20000080 = 0); NONFAILING(*(uint32_t*)0x20000088 = 0x6c0); NONFAILING(*(uint64_t*)0x20000090 = 0x20000040); NONFAILING(*(uint64_t*)0x20000040 = 0x20000000); NONFAILING(*(uint32_t*)0x20000000 = 0x28); NONFAILING(*(uint16_t*)0x20000004 = 0x10); NONFAILING(*(uint16_t*)0x20000006 = 0x801); NONFAILING(*(uint32_t*)0x20000008 = 0); NONFAILING(*(uint32_t*)0x2000000c = 0); NONFAILING(*(uint8_t*)0x20000010 = 0); NONFAILING(*(uint8_t*)0x20000011 = 0); NONFAILING(*(uint16_t*)0x20000012 = 0); NONFAILING(*(uint32_t*)0x20000014 = r[2]); NONFAILING(*(uint32_t*)0x20000018 = 0); NONFAILING(*(uint32_t*)0x2000001c = 0); NONFAILING(*(uint16_t*)0x20000020 = 8); NONFAILING(*(uint16_t*)0x20000022 = 0x1c); NONFAILING(*(uint8_t*)0x20000024 = 0xef); 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); syscall(__NR_sendmsg, r[0], 0x20000080ul, 0ul); } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); install_segv_handler(); do_sandbox_none(); return 0; }