1#!/bin/sh 2 3# panic: Bad tailq NEXT(0xffffffff81cb0ba0->tqh_last) != NULL 4# cpuid = 0 5# time = 1605424954 6# KDB: stack backtrace: 7# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe010125c2e0 8# vpanic() at vpanic+0x182/frame 0xfffffe010125c330 9# panic() at panic+0x43/frame 0xfffffe010125c390 10# callout_process() at callout_process+0x34f/frame 0xfffffe010125c400 11# handleevents() at handleevents+0x185/frame 0xfffffe010125c440 12# timercb() at timercb+0x196/frame 0xfffffe010125c490 13# lapic_handle_timer() at lapic_handle_timer+0x9b/frame 0xfffffe010125c4c0 14# Xtimerint() at Xtimerint+0xb1/frame 0xfffffe010125c4c0 15# --- interrupt, rip = 0xffffffff80c56c69, rsp = 0xfffffe010125c590, rbp = 0xfffffe010125c5c0 --- 16# witness_unlock() at witness_unlock+0x79/frame 0xfffffe010125c5c0 17# __mtx_unlock_flags() at __mtx_unlock_flags+0x4d/frame 0xfffffe010125c5f0 18# kqueue_register() at kqueue_register+0x9e3/frame 0xfffffe010125c680 19# kqueue_kevent() at kqueue_kevent+0x106/frame 0xfffffe010125c950 20# kern_kevent_fp() at kern_kevent_fp+0x95/frame 0xfffffe010125c9a0 21# kern_kevent() at kern_kevent+0x80/frame 0xfffffe010125ca00 22# kern_kevent_generic() at kern_kevent_generic+0x70/frame 0xfffffe010125ca60 23# sys_kevent() at sys_kevent+0x61/frame 0xfffffe010125cac0 24# amd64_syscall() at amd64_syscall+0x144/frame 0xfffffe010125cbf0 25# fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe010125cbf0 26# --- syscall (0, FreeBSD ELF64, nosys), rip = 0x800380c6a, rsp = 0x7fffffffe4d8, rbp = 0x7fffffffe500 --- 27# KDB: enter: panic 28# [ thread pid 36082 tid 144846 ] 29# Stopped at kdb_enter+0x37: movq $0,0x10aa7f6(%rip) 30# db> x/s version 31# version: FreeBSD 13.0-CURRENT #0 r367672: Sat Nov 14 08:42:14 CET 2020 32# pho@t2.osted.lan:/usr/src/sys/amd64/compile/PHO 33# db> 34 35[ `uname -p` != "amd64" ] && exit 0 36 37# Fixed by r367849 38 39. ../default.cfg 40cat > /tmp/syzkaller27.c <<EOF 41// https://syzkaller.appspot.com/bug?id=6b64d673525304a89af91e0db71f2dee8e8da0f7 42// autogenerated by syzkaller (https://github.com/google/syzkaller) 43// Reported-by: syzbot+79569cd4d76636b2cc1c@syzkaller.appspotmail.com 44 45#define _GNU_SOURCE 46 47#include <sys/types.h> 48 49#include <pwd.h> 50#include <signal.h> 51#include <stdarg.h> 52#include <stdbool.h> 53#include <stdint.h> 54#include <stdio.h> 55#include <stdlib.h> 56#include <string.h> 57#include <sys/endian.h> 58#include <sys/syscall.h> 59#include <sys/wait.h> 60#include <time.h> 61#include <unistd.h> 62 63static void kill_and_wait(int pid, int* status) 64{ 65 kill(pid, SIGKILL); 66 while (waitpid(-1, status, 0) != pid) { 67 } 68} 69 70static void sleep_ms(uint64_t ms) 71{ 72 usleep(ms * 1000); 73} 74 75static uint64_t current_time_ms(void) 76{ 77 struct timespec ts; 78 if (clock_gettime(CLOCK_MONOTONIC, &ts)) 79 exit(1); 80 return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; 81} 82 83static void execute_one(void); 84 85#define WAIT_FLAGS 0 86 87static void loop(void) 88{ 89 int iter __unused = 0; 90 for (;; iter++) { 91 int pid = fork(); 92 if (pid < 0) 93 exit(1); 94 if (pid == 0) { 95 execute_one(); 96 exit(0); 97 } 98 int status = 0; 99 uint64_t start = current_time_ms(); 100 for (;;) { 101 if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) 102 break; 103 sleep_ms(1); 104 if (current_time_ms() - start < 5 * 1000) 105 continue; 106 kill_and_wait(pid, &status); 107 break; 108 } 109 } 110} 111 112uint64_t r[1] = {0xffffffffffffffff}; 113 114void execute_one(void) 115{ 116 intptr_t res = 0; 117 res = syscall(SYS_kqueue); 118 if (res != -1) 119 r[0] = res; 120 *(uint64_t*)0x200000c0 = 0; 121 *(uint16_t*)0x200000c8 = 0xfff9; 122 *(uint16_t*)0x200000ca = 0x4001; 123 *(uint32_t*)0x200000cc = 4; 124 *(uint64_t*)0x200000d0 = 0; 125 *(uint64_t*)0x200000d8 = 0; 126 *(uint64_t*)0x200000e0 = 0; 127 *(uint64_t*)0x200000e8 = 0; 128 *(uint64_t*)0x200000f0 = 0; 129 *(uint64_t*)0x200000f8 = 0; 130 syscall(SYS_kevent, r[0], 0x200000c0ul, 1ul, 0ul, 0ul, 0ul); 131} 132int main(void) 133{ 134 sleep(2); /* pho */ 135 syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); 136 loop(); 137 return 0; 138} 139EOF 140mycc -o /tmp/syzkaller27 -Wall -Wextra -O0 /tmp/syzkaller27.c || 141 exit 1 142 143(cd ../testcases/swap; ./swap -t 1m -i 20 -h > /dev/null 2>&1) & 144for i in `jot 256`; do 145 (cd /tmp; timeout 3m ./syzkaller27) & 146done 147wait 148 149rm -rf /tmp/syzkaller27 /tmp/syzkaller27.c /tmp/syzkaller.* 150exit 0 151