// https://syzkaller.appspot.com/bug?id=3c1f47967b7cbd399d3ba3e65f297a29aa1c5f92 // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #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 #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; \ } struct csum_inet { uint32_t acc; }; static void csum_inet_init(struct csum_inet* csum) { csum->acc = 0; } static void csum_inet_update(struct csum_inet* csum, const uint8_t* data, size_t length) { if (length == 0) return; size_t i; for (i = 0; i < length - 1; i += 2) csum->acc += *(uint16_t*)&data[i]; if (length & 1) csum->acc += (uint16_t)data[length - 1]; while (csum->acc > 0xffff) csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16); } static uint16_t csum_inet_digest(struct csum_inet* csum) { return ~csum->acc; } 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 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; NONFAILING(strncpy(buf, (char*)a0, sizeof(buf))); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } long r[1]; void loop() { memset(r, -1, sizeof(r)); syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); NONFAILING(memcpy((void*)0x20e48000, "/dev/sg#", 9)); r[0] = syz_open_dev(0x20e48000, 0, 0x802); NONFAILING(*(uint8_t*)0x20efef0b = 0); NONFAILING(*(uint8_t*)0x20efef0c = 0); NONFAILING(*(uint16_t*)0x20efef0d = 0); NONFAILING(*(uint16_t*)0x20efef0f = 0); NONFAILING(*(uint16_t*)0x20efef11 = 0); NONFAILING(*(uint16_t*)0x20efef13 = 0); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef15, 0, 0, 4)); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef15, 6, 4, 4)); NONFAILING(memcpy((void*)0x20efef16, "\x73\x9e\x3f", 3)); NONFAILING(*(uint16_t*)0x20efef19 = htobe16(0x10)); NONFAILING(*(uint8_t*)0x20efef1b = 0); NONFAILING(*(uint8_t*)0x20efef1c = 0); NONFAILING(*(uint8_t*)0x20efef1d = 0xfe); NONFAILING(*(uint8_t*)0x20efef1e = 0x80); NONFAILING(*(uint8_t*)0x20efef1f = 0); NONFAILING(*(uint8_t*)0x20efef20 = 0); NONFAILING(*(uint8_t*)0x20efef21 = 0); NONFAILING(*(uint8_t*)0x20efef22 = 0); NONFAILING(*(uint8_t*)0x20efef23 = 0); NONFAILING(*(uint8_t*)0x20efef24 = 0); NONFAILING(*(uint8_t*)0x20efef25 = 0); NONFAILING(*(uint8_t*)0x20efef26 = 0); NONFAILING(*(uint8_t*)0x20efef27 = 0); NONFAILING(*(uint8_t*)0x20efef28 = 0); NONFAILING(*(uint8_t*)0x20efef29 = 0); NONFAILING(*(uint8_t*)0x20efef2a = 0); NONFAILING(*(uint8_t*)0x20efef2b = 0); NONFAILING(*(uint8_t*)0x20efef2c = 0xbb); NONFAILING(*(uint8_t*)0x20efef2d = -1); NONFAILING(*(uint8_t*)0x20efef2e = 1); NONFAILING(*(uint8_t*)0x20efef2f = 0); NONFAILING(*(uint8_t*)0x20efef30 = 0); NONFAILING(*(uint8_t*)0x20efef31 = 0); NONFAILING(*(uint8_t*)0x20efef32 = 0); NONFAILING(*(uint8_t*)0x20efef33 = 0); NONFAILING(*(uint8_t*)0x20efef34 = 0); NONFAILING(*(uint8_t*)0x20efef35 = 0); NONFAILING(*(uint8_t*)0x20efef36 = 0); NONFAILING(*(uint8_t*)0x20efef37 = 0); NONFAILING(*(uint8_t*)0x20efef38 = 0); NONFAILING(*(uint8_t*)0x20efef39 = 0); NONFAILING(*(uint8_t*)0x20efef3a = 0); NONFAILING(*(uint8_t*)0x20efef3b = 0); NONFAILING(*(uint8_t*)0x20efef3c = 1); NONFAILING(*(uint16_t*)0x20efef3d = 0); NONFAILING(*(uint16_t*)0x20efef3f = 0); NONFAILING(*(uint8_t*)0x20efef41 = 4); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef42, 1, 0, 4)); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef42, 0, 4, 4)); NONFAILING(*(uint16_t*)0x20efef43 = 0); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef45, 0, 0, 1)); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef45, 0, 1, 4)); NONFAILING(STORE_BY_BITMASK(uint8_t, 0x20efef45, 0, 5, 3)); NONFAILING(memcpy((void*)0x20efef46, "\x83\xd4\xb5", 3)); NONFAILING(*(uint8_t*)0x20efef49 = 0); NONFAILING(memcpy((void*)0x20efef4a, "\xff\x00\xa4", 3)); struct csum_inet csum_1; csum_inet_init(&csum_1); NONFAILING(csum_inet_update(&csum_1, (const uint8_t*)0x20efef1d, 16)); NONFAILING(csum_inet_update(&csum_1, (const uint8_t*)0x20efef2d, 16)); uint32_t csum_1_chunk_2 = 0x10000000; csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 4); uint32_t csum_1_chunk_3 = 0x21000000; csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 4); NONFAILING(csum_inet_update(&csum_1, (const uint8_t*)0x20efef3d, 16)); NONFAILING(*(uint16_t*)0x20efef43 = csum_inet_digest(&csum_1)); syscall(__NR_write, r[0], 0x20efef0b, 0x42); syscall(__NR_read, r[0], 0x201eb000, 0xb3); } int main() { install_segv_handler(); loop(); return 0; }