// https://syzkaller.appspot.com/bug?id=3153e27944712d6149bbd81691fdcdc7cbdc0e60 // 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 __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 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) - 1); 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 = 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; sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } #ifndef __NR_memfd_create #define __NR_memfd_create 319 #endif uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one() { long res = 0; memcpy((void*)0x20000200, "/dev/loop#", 11); res = syz_open_dev(0x20000200, 0, 0); if (res != -1) r[0] = res; memcpy((void*)0x20000080, "\x74\x08\x6e\x75\x00\x00\x00\x00\x00\x00\x00\x00\x00\x8c\x00", 15); res = syscall(__NR_memfd_create, 0x20000080, 0); if (res != -1) r[1] = res; *(uint64_t*)0x20000340 = 0x200001c0; memcpy((void*)0x200001c0, "'", 1); *(uint64_t*)0x20000348 = 1; syscall(__NR_pwritev, r[1], 0x20000340, 1, 0x1081806); syscall(__NR_ioctl, r[0], 0x4c00, r[1]); memcpy((void*)0x20000200, "/dev/loop#", 11); res = syz_open_dev(0x20000200, 0, 0); if (res != -1) r[2] = res; syscall(__NR_ioctl, r[2], 0x4c06, r[2]); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); for (;;) { int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } }