// https://syzkaller.appspot.com/bug?id=765feadcdeac922f999d7edd5e4823842cdf7904 // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include static __thread int clone_ongoing; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { exit(sig); } uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; int valid = addr < prog_start || addr > prog_end; if (skip && valid) { _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(...) \ ({ \ int ok = 1; \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } else \ ok = 0; \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ ok; \ }) static long syz_open_dev(volatile long a0, volatile long a1, volatile long 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); } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); const char* reason; (void)reason; install_segv_handler(); intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } NONFAILING(memcpy((void*)0x20000000, "./file0\000", 8)); syscall(__NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x20000000ul, /*mode=*/0ul); NONFAILING(memcpy((void*)0x200001c0, "syz\000", 4)); NONFAILING(memcpy((void*)0x20000480, "./file0\000", 8)); NONFAILING(memcpy((void*)0x200004c0, "9p\000", 3)); NONFAILING( memcpy((void*)0x20000840, "\x78\x22\x6e\x6f\x65\x78\x61\x63\x63\x81\x73\x73\x3d\x61\x6e\x79" "\x2c\x63\x61\x63\x68\x65\x3d\x66\x73\x63\x61\x63\x68\x65", 30)); syscall(__NR_mount, /*src=*/0x200001c0ul, /*dst=*/0x20000480ul, /*type=*/0x200004c0ul, /*flags=*/0ul, /*opts=*/0x20000840ul); NONFAILING(memcpy((void*)0x20000080, "./file0\000", 8)); syscall(__NR_chdir, /*dir=*/0x20000080ul); NONFAILING(memcpy((void*)0x200000c0, "cgroup.kill\000", 12)); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000c0ul, /*flags=*/0x275a, /*mode=*/0); if (res != -1) r[0] = res; syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0xb36000ul, /*prot=PROT_WRITE*/ 2ul, /*flags=MAP_STACK|MAP_POPULATE|MAP_FIXED|MAP_SHARED*/ 0x28011ul, /*fd=*/r[0], /*offset=*/0ul); NONFAILING(*(uint32_t*)0x20000280 = 0xb); NONFAILING(*(uint8_t*)0x20000284 = 0x75); NONFAILING(*(uint16_t*)0x20000285 = 2); NONFAILING(*(uint32_t*)0x20000287 = 0); syscall(__NR_write, /*fd=*/r[0], /*data=*/0x20000280ul, /*size=*/0xbul); NONFAILING(memcpy((void*)0x20000100, "/dev/audio#\000", 12)); res = -1; NONFAILING(res = syz_open_dev( /*dev=*/0x20000100, /*id=*/6, /*flags=O_NONBLOCK|O_NOCTTY|O_NOATIME|O_DIRECT|O_CREAT|0x1002*/ 0x45942)); if (res != -1) r[1] = res; NONFAILING(*(uint64_t*)0x20000140 = 2); syscall(__NR_sendfile, /*fdout=*/r[1], /*fdin=*/r[0], /*off=*/0x20000140ul, /*count=*/0x80000000ul); return 0; }