// https://syzkaller.appspot.com/bug?id=d76010e619e43826b534d5f0684691bf6bd3cd75 // 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 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; } static void thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } 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_sysctl() { static struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/net/ipv4/ping_group_range", "0 65535"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/nr_overcommit_hugepages", "4"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) printf("write to %s failed: %s\n", files[i].name, strerror(errno)); } } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void loop(void) { int i, call, thread; int collide = 0; again: for (call = 0; call < 7; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); if (collide && (call % 2) == 0) break; event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); if (!collide) { collide = 1; goto again; } } #ifndef __NR_memfd_create #define __NR_memfd_create 319 #endif uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: memcpy( (void*)0x20000900, "Y\377\377\000\000\000\000\000K\262\002\200B\351\350\314\336\006\000l" "\250\032J\257\262M\272\270_\005U\315<|>\236\354^\016\276\030+-" "\233\2113\002\000\246\037+" "\263\305\220z5\340\337i\267\237\264QW\311\311\222\003\t\000\000\000" "\000\000\262\017\356\276\f8\314\177\000\000\000Z\201\000\000\000\000" "\030I\023\361\242x\004\201R\3245R\256\204\315N\367\366\b~\355_M^dQ:" "\274\257q\210\031nSF|;]\341A\214\212\230\327|\334LF\r\261\375\277!" "\307u\314P\335\023~\211\317\205\312\240%" "\306\307\021\000\000\000\000\000\000\000?M9\\\av~\'\331\260\254dya]" "8\235\267\v\3639\305{\234!\017/" "\270o8\271\215\031\342\312\001y\203\347\ng\207\3313<" "u\276\352g\322\004e\362s\336}o#\220\332\234s,r\375:" "\313\307\vTmPZJ\254\213\320\300\274RK\313\0368\316\275[N\260\264<" "\353\206[\354\217\024\n\203\236&\\\267!\355\240\303," "\220m\017\000\000\000\000\000\000\377\320\263\224\000\000\000\000\000" "\000\000\235H\370\377Ro\243W\341\355\216S\256X\223\177\323\271a\344" "\340\275\331\365\344e\371\312m\343\003\344\255\325&" "A\002\310\251\376\313\207\331\323\214\f\3008T~\304\275\220?" "\037\234\2330\031 " "\237\321p`\300/" "\000u\031\035\254\350%" "\267\t\2374\273\211\351\301\201\260\326\367\005\026\271\351\334~\323-" "s\346;\224\034^\006\332v;\314D\225sj\340\325\276S\254\345N\352\236yl[[" "\3165\356\005\234\226\253J^c\367\031\264\330\344\207\235p\352?/" "\313\232\2525\'Q\fuG\201\212@\227M=v\376\a\253p\363\223\235\177@" "9\300\322\361#\347N\211\370\350+" "\241\202\023\262\251\357\245\370\213k\263\236v\222\016\321\037\027Dx[" "\255\260\235/" "\226\3442mO\237h\352\363\024\315\226\211_)\033\342\326\b\224b\257;" "\222T\257z\224\237G\373\375|$k\003\327;\232y\356\371W?\263\371\370I." "E4\303eWq\372\":$\320\027Q\224\365\345mk\216&\361;#z\357*" "\316\231\004\271\220\274\271#-" "\215i\256\305\337\023\322K\213\365\f\262x\335\325\264\251^~O<" "\022\343\303P|7\251\310\261r0Z\230\207^" "\310C\033\226\264lsyF\305\274\377OE\351\3270\347\376p\203\247\241\331" "\344\272\222\027\277\340\341\001\267\213\030j\031n\310\377\351\364\364" "\317 " "a\327_w\017\235F\256\314A-/" "\203\253U\325\2778\244O\264\357\310\314H\321=\276\265O\025\307;" "Lb\316\032\314\230\350\351e\340\302N\347\327\035\222\207F8\236\367\335" "\332W\365X\200\240f\316o\330\177\300\226\bSB\316&\004$" "\303\3431U\204\202\360{i\035\002\020\306C\001^\317\223?" "w\001\204\240\326\242\020\244\374G\253D\326dGZ\262Cx\033\375D9\027\346" "\312uM\343\005)\342[\342j$F1n@\336\n%t.[\255\265\f<" "o\333\244\220\304\320I\246\226\241\000\273\335\224\000t/" "1YekG\177\275rI\036\2124=\242\351\3701\255\356\365\244\005#" "\177\250\037\024\202ih\371?\003Q\365\304\225\231 " "\247v~:$" "\002O\343\252\360o\353k\'\322q\020\036\224n\327w\261\310G\211\364\214t" "\371R\205\0338OE\004\232\330\200\020x\277\n0\b,r\306r\367=" "\376\301\026\346\356\273:-h\272\213\024\232?\216\003;" "\345\004\330\251\232\323E(\177|\255U\257e\207V.i4$6U,R\233\n{" "\'\3761\304\2609", 965); res = syscall(__NR_memfd_create, 0x20000900ul, 4ul); if (res != -1) r[0] = res; break; case 1: syscall(__NR_mmap, 0x20200000ul, 0x400017ul, 0x2000006ul, 0x2012ul, r[0], 0ul); break; case 2: res = syscall(__NR_socket, 2ul, 1ul, 0); if (res != -1) r[1] = res; break; case 3: *(uint16_t*)0x200001c0 = 2; *(uint16_t*)0x200001c2 = htobe16(0x4e20); *(uint32_t*)0x200001c4 = htobe32(0xe0000002); syscall(__NR_bind, r[1], 0x200001c0ul, 0x10ul); break; case 4: *(uint32_t*)0x20000000 = 1; syscall(__NR_setsockopt, r[1], 1, 0x3c, 0x20000000ul, 0x1039cul); break; case 5: *(uint16_t*)0x20000080 = 2; *(uint16_t*)0x20000082 = htobe16(0x4e20); *(uint32_t*)0x20000084 = htobe32(0); syscall(__NR_sendto, r[1], 0ul, 0ul, 0x20000000ul, 0x20000080ul, 0x10ul); break; case 6: memcpy( (void*)0x20000140, "\x7c\x0d\x11\x13\x17\xb1\xff\x8e\xc8\xf2\x9f\x81\x31\x9e\xc5\xb1\x0d" "\x0d\x41\x3f\xfa\xef\xd9\x44\x8d\xbe\xf1\xff\xb4\xe3\xa6\xaf\x87\x13" "\x15\x12\xda\x52\x8f\x62\x35\xfe\x35\xd3\x05\x3b\x5c\xb4\x87\x7c\x1b" "\x89\xbb\xf8\x3f\x6d\x74\x9d\x5b\x45\x67\x96\x01\xa3\xab\xdc\x20\x4c" "\xf1\xad\x79\x72\x52\xbb\x0c\x7b\x43\xe3\xe9\x76\x32\x21\xcb\x2c\x8d" "\x76\xf8\x24\xf4\xbe\xa3\x38\xf5\x3a\xa7\x57\x03\xf4\x65\xe5\x0e\x43" "\x4e\x21\x93\x90\x0c\x39\xab\x79\xd3\x7c\xc0\xce\x7a", 115); syscall(__NR_sendto, r[1], 0x20000140ul, 0xffffffffffffffd0ul, 0x401c005ul, 0ul, 0xffffffffffffff36ul); break; } } 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); setup_sysctl(); loop(); return 0; }