#!/bin/sh # panic: Thread not suspended # cpuid = 9 # time = 1651215111 # KDB: stack backtrace: # db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe018701d9c0 # vpanic() at vpanic+0x17f/frame 0xfffffe018701da10 # panic() at panic+0x43/frame 0xfffffe018701da70 # thread_unsuspend_one() at thread_unsuspend_one+0xc5/frame 0xfffffe018701daa0 # thread_suspend_check() at thread_suspend_check+0x1f8/frame 0xfffffe018701dae0 # exit1() at exit1+0xb7/frame 0xfffffe018701db50 # sigexit() at sigexit+0x157/frame 0xfffffe018701de20 # postsig() at postsig+0x1aa/frame 0xfffffe018701def0 # ast() at ast+0x4fb/frame 0xfffffe018701df30 # doreti_ast() at doreti_ast+0x1f/frame 0x820bf50f0 # KDB: enter: panic # [ thread pid 8379 tid 100392 ] # Stopped at kdb_enter+0x32: movq $0,0x12790b3(%rip) # db> x/s version # FreeBSD 14.0-CURRENT #0 main-n255099-0923ff82fb383: Thu Apr 28 09:48:48 CEST 2022 # pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO # db> [ `uname -p` != "amd64" ] && exit 0 . ../default.cfg cat > /tmp/syzkaller53.c < #include #include #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 __unused) { 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 (sig == SIGBUS) valid = 1; 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 __unused = 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(*(uint32_t*)0x20000080 = 0x13); NONFAILING(*(uint32_t*)0x20000084 = 0); NONFAILING(*(uint32_t*)0x20000088 = 0); NONFAILING(*(uint32_t*)0x2000008c = 0); NONFAILING(*(uint32_t*)0x20000090 = -1); NONFAILING(memset((void*)0x20000094, 0, 60)); syscall(SYS_procctl, 0ul, 0, 6ul, 0x20000080ul); } int main(void) { syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); install_segv_handler(); loop(); return 0; } EOF mycc -o /tmp/syzkaller53 -Wall -Wextra -O0 /tmp/syzkaller53.c || exit 1 for i in `jot 20`; do (cd /tmp; timeout 3m ./syzkaller53) & done wait rm -rf /tmp/syzkaller53 /tmp/syzkaller53.c /tmp/syzkaller53.* exit 0