// https://syzkaller.appspot.com/bug?id=c8baf7fc53c98268f450cb196098fdb502aa071c // 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 #ifndef SYS_mkdir #define SYS_mkdir 136 #endif #ifndef SYS_mmap #define SYS_mmap 197 #endif #ifndef SYS_open #define SYS_open 5 #endif #ifndef SYS_swapctl #define SYS_swapctl 271 #endif #ifndef SYS_truncate #define SYS_truncate 200 #endif static unsigned long long procid; 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_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 void kill_and_wait(int pid, int* status) { kill(pid, SIGKILL); while (waitpid(-1, status, 0) != pid) { } } 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 execute_one(void); #define WAIT_FLAGS 0 static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } void execute_one(void) { NONFAILING(memcpy((void*)0x20000480, "./file0\000", 8)); syscall(SYS_open, /*file=*/0x20000480ul, /*flags=*/0x80400000000206ul, /*mode=*/0ul); NONFAILING(memcpy((void*)0x20000040, "./file0\000", 8)); syscall(SYS_truncate, /*file=*/0x20000040ul, /*pad=*/0ul, /*len=*/0x80000001ul); NONFAILING(memcpy((void*)0x20000000, "./file0\000", 8)); syscall(SYS_mkdir, /*path=*/0x20000000ul, /*mode=*/0ul); syscall(SYS_swapctl, /*cmd=*/1ul, /*arg=*/0x20000000ul, /*misc=*/1); NONFAILING(memcpy((void*)0x200000c0, "./file0\000", 8)); syscall(SYS_open, /*file=*/0x200000c0ul, /*flags=*/0ul, /*mode=*/0ul); syscall(SYS_swapctl, /*cmd=*/2ul, /*arg=*/0x200000c0ul, /*misc=*/0); } int main(void) { syscall(SYS_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/3ul, /*flags=*/0x1012ul, /*fd=*/-1, /*pad=*/0ul, /*offset=*/0ul); install_segv_handler(); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }