#!/bin/sh # panic: sbflush_internal: ccc 0 mb 0 mbcnt 256 # cpuid = 4 # time = 1592126385 # KDB: stack backtrace: # db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe012b22f8d0 # vpanic() at vpanic+0x182/frame 0xfffffe012b22f920 # panic() at panic+0x43/frame 0xfffffe012b22f980 # sbrelease_internal() at sbrelease_internal+0xbd/frame 0xfffffe012b22f9a0 # solisten_proto() at solisten_proto+0xab/frame 0xfffffe012b22fa00 # sctp_listen() at sctp_listen+0x2f4/frame 0xfffffe012b22fa60 # solisten() at solisten+0x42/frame 0xfffffe012b22fa80 # kern_listen() at kern_listen+0x7c/frame 0xfffffe012b22fac0 # ia32_syscall() at ia32_syscall+0x150/frame 0xfffffe012b22fbf0 # int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0xffffdb10 # KDB: enter: panic # [ thread pid 93263 tid 100202 ] # Stopped at kdb_enter+0x37: movq $0,0x10c5456(%rip) # db> x/s version # version: FreeBSD 13.0-CURRENT #0 r362171: Sun Jun 14 09:06:12 CEST 2020 # pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO # db> [ `uname -p` != "amd64" ] && exit 0 . ../default.cfg kldstat -v | grep -q sctp || kldload sctp.ko cat > /tmp/syzkaller15.c < #include #include #include #include #include #include #include #include #include #include #include #include #include #include static unsigned long long procid; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx __unused) { 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); } 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(...) \ { \ __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 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; for (iter = 0;; 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 < 5 * 1000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; res = syscall(SYS_socket, 0x1c, 1, 0x84); if (res != -1) r[0] = res; NONFAILING(*(uint8_t*)0x10000040 = 0xc8); NONFAILING(*(uint8_t*)0x10000041 = 0x51); NONFAILING(*(uint8_t*)0x10000042 = 0); NONFAILING(*(uint8_t*)0x10000043 = 0); NONFAILING(*(uint8_t*)0x10000044 = 0); NONFAILING(*(uint8_t*)0x10000045 = 0); NONFAILING(*(uint8_t*)0x10000046 = 0); NONFAILING(*(uint8_t*)0x10000047 = 0); NONFAILING(*(uint8_t*)0x10000048 = 0); NONFAILING(*(uint8_t*)0x10000049 = 0); NONFAILING(*(uint8_t*)0x1000004a = 0); syscall(SYS_setsockopt, (intptr_t)r[0], 0x84, 0xc, 0x10000040, 0xb); NONFAILING(*(uint8_t*)0x10000180 = 0x5f); NONFAILING(*(uint8_t*)0x10000181 = 0x1c); NONFAILING(*(uint16_t*)0x10000182 = htobe16(0x4e22 + procid * 4)); NONFAILING(*(uint32_t*)0x10000184 = 0); NONFAILING(*(uint64_t*)0x10000188 = htobe64(0)); NONFAILING(*(uint64_t*)0x10000190 = htobe64(1)); NONFAILING(*(uint32_t*)0x10000198 = 0); syscall(SYS_connect, (intptr_t)r[0], 0x10000180, 0x1c); syscall(SYS_listen, (intptr_t)r[0], 7); } int main(void) { syscall(SYS_mmap, 0x10000000, 0x1000000, 7, 0x1012, -1, 0); install_segv_handler(); for (procid = 0; procid < 4; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; } EOF mycc -o /tmp/syzkaller15 -Wall -Wextra -O0 -m32 /tmp/syzkaller15.c || exit 1 (cd /tmp; ./syzkaller15) & sleep 60 pkill -9 syzkaller15 wait rm -f /tmp/syzkaller15 /tmp/syzkaller15.c /tmp/syzkaller15.core exit 0