// 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 __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 #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 __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 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 setup_cgroups() { if (mkdir("/syzcgroup", 0777)) { } if (mkdir("/syzcgroup/unified", 0777)) { } if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) { } if (chmod("/syzcgroup/unified", 0777)) { } if (!write_file("/syzcgroup/unified/cgroup.subtree_control", "+cpu +memory +io +pids +rdma")) { } if (mkdir("/syzcgroup/cpu", 0777)) { } if (mount("none", "/syzcgroup/cpu", "cgroup", 0, "cpuset,cpuacct,perf_event,hugetlb")) { } if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) { } if (chmod("/syzcgroup/cpu", 0777)) { } if (mkdir("/syzcgroup/net", 0777)) { } if (mount("none", "/syzcgroup/net", "cgroup", 0, "net_cls,net_prio,devices,freezer")) { } if (chmod("/syzcgroup/net", 0777)) { } } static void setup_binfmt_misc() { if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:syz0::./file0:")) { } if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:yz1::./file0:POC")) { } } 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 do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; setup_cgroups(); setup_binfmt_misc(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } unsigned long long procid; void execute_one() { NONFAILING(*(uint64_t*)0x20000000 = 0x20000040); NONFAILING(*(uint64_t*)0x20000008 = 0); syscall(__NR_writev, -1, 0x20000000, 1); NONFAILING(memcpy((void*)0x20000800, "./cgroup/syz0", 14)); syscall(__NR_mkdirat, 0xffffffffffffff9c, 0x20000800, 0x1ff); NONFAILING(*(uint32_t*)0x20940000 = 2); NONFAILING(*(uint32_t*)0x20940004 = 0x78); NONFAILING(*(uint8_t*)0x20940008 = 0xfd); NONFAILING(*(uint8_t*)0x20940009 = 0); NONFAILING(*(uint8_t*)0x2094000a = 0); NONFAILING(*(uint8_t*)0x2094000b = 0); NONFAILING(*(uint32_t*)0x2094000c = 0); NONFAILING(*(uint64_t*)0x20940010 = 0); NONFAILING(*(uint64_t*)0x20940018 = 0); NONFAILING(*(uint64_t*)0x20940020 = 0); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 0, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 1, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 2, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 3, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 4, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 3, 5, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 6, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 7, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 8, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 9, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 10, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 11, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 12, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 13, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 14, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 15, 2)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 17, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 18, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 19, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 20, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 21, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 22, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 23, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 24, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 25, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 26, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 27, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 28, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20940028, 0, 29, 35)); NONFAILING(*(uint32_t*)0x20940030 = 0); NONFAILING(*(uint32_t*)0x20940034 = 0); NONFAILING(*(uint64_t*)0x20940038 = 0x20000000); NONFAILING(*(uint64_t*)0x20940040 = 0); NONFAILING(*(uint64_t*)0x20940048 = 0); NONFAILING(*(uint64_t*)0x20940050 = 0); NONFAILING(*(uint32_t*)0x20940058 = 0); NONFAILING(*(uint32_t*)0x2094005c = 0); NONFAILING(*(uint64_t*)0x20940060 = 0); NONFAILING(*(uint32_t*)0x20940068 = 0); NONFAILING(*(uint16_t*)0x2094006c = 0); NONFAILING(*(uint16_t*)0x2094006e = 0); syscall(__NR_perf_event_open, 0x20940000, 0, 0, -1, 0); } 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) { install_segv_handler(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } } } sleep(1000000); return 0; }