1*8a272653SPeter Holm#!/bin/sh 2*8a272653SPeter Holm 3*8a272653SPeter Holm# panic: refcount 0xfffff8001dd678e8 wraparound 4*8a272653SPeter Holm# cpuid = 4 5*8a272653SPeter Holm# time = 1580840365 6*8a272653SPeter Holm# KDB: stack backtrace: 7*8a272653SPeter Holm# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00e56517b0 8*8a272653SPeter Holm# vpanic() at vpanic+0x185/frame 0xfffffe00e5651810 9*8a272653SPeter Holm# panic() at panic+0x43/frame 0xfffffe00e5651870 10*8a272653SPeter Holm# _refcount_update_saturated() at _refcount_update_saturated+0x15/frame 0xfffffe00e5651880 11*8a272653SPeter Holm# refcount_release_last() at refcount_release_last+0x7c/frame 0xfffffe00e56518a0 12*8a272653SPeter Holm# closef() at closef+0x1f7/frame 0xfffffe00e5651930 13*8a272653SPeter Holm# fdescfree_fds() at fdescfree_fds+0x3c/frame 0xfffffe00e5651980 14*8a272653SPeter Holm# fdescfree() at fdescfree+0x456/frame 0xfffffe00e5651a40 15*8a272653SPeter Holm# exit1() at exit1+0x4f3/frame 0xfffffe00e5651ab0 16*8a272653SPeter Holm# sys_sys_exit() at sys_sys_exit+0xd/frame 0xfffffe00e5651ac0 17*8a272653SPeter Holm# amd64_syscall() at amd64_syscall+0x2f1/frame 0xfffffe00e5651bf0 18*8a272653SPeter Holm# fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00e5651bf0 19*8a272653SPeter Holm# --- syscall (1, FreeBSD ELF64, sys_sys_exit), rip = 0x8003d53ba, rsp = 0x7fffffffe9f8, rbp = 0x7fffffffea10 --- 20*8a272653SPeter Holm 21*8a272653SPeter Holm# Fixed by r357554 22*8a272653SPeter Holm 23*8a272653SPeter Holm. ../default.cfg 24*8a272653SPeter Holmcat > /tmp/syzkaller1.c <<EOF 25*8a272653SPeter Holm 26*8a272653SPeter Holm// https://syzkaller.appspot.com/bug?id=29c002256f2ce0d521d1ce007c74e456a37495a8 27*8a272653SPeter Holm// autogenerated by syzkaller (https://github.com/google/syzkaller) 28*8a272653SPeter Holm 29*8a272653SPeter Holm#define _GNU_SOURCE 30*8a272653SPeter Holm 31*8a272653SPeter Holm#include <errno.h> 32*8a272653SPeter Holm#include <pthread.h> 33*8a272653SPeter Holm#include <pwd.h> 34*8a272653SPeter Holm#include <stdarg.h> 35*8a272653SPeter Holm#include <stdbool.h> 36*8a272653SPeter Holm#include <stdint.h> 37*8a272653SPeter Holm#include <stdio.h> 38*8a272653SPeter Holm#include <stdlib.h> 39*8a272653SPeter Holm#include <string.h> 40*8a272653SPeter Holm#include <sys/endian.h> 41*8a272653SPeter Holm#include <sys/syscall.h> 42*8a272653SPeter Holm#include <time.h> 43*8a272653SPeter Holm#include <unistd.h> 44*8a272653SPeter Holm 45*8a272653SPeter Holmstatic void sleep_ms(uint64_t ms) 46*8a272653SPeter Holm{ 47*8a272653SPeter Holm usleep(ms * 1000); 48*8a272653SPeter Holm} 49*8a272653SPeter Holm 50*8a272653SPeter Holmstatic uint64_t current_time_ms(void) 51*8a272653SPeter Holm{ 52*8a272653SPeter Holm struct timespec ts; 53*8a272653SPeter Holm if (clock_gettime(CLOCK_MONOTONIC, &ts)) 54*8a272653SPeter Holm exit(1); 55*8a272653SPeter Holm return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; 56*8a272653SPeter Holm} 57*8a272653SPeter Holm 58*8a272653SPeter Holmstatic void thread_start(void* (*fn)(void*), void* arg) 59*8a272653SPeter Holm{ 60*8a272653SPeter Holm pthread_t th; 61*8a272653SPeter Holm pthread_attr_t attr; 62*8a272653SPeter Holm pthread_attr_init(&attr); 63*8a272653SPeter Holm pthread_attr_setstacksize(&attr, 128 << 10); 64*8a272653SPeter Holm int i; 65*8a272653SPeter Holm for (i = 0; i < 100; i++) { 66*8a272653SPeter Holm if (pthread_create(&th, &attr, fn, arg) == 0) { 67*8a272653SPeter Holm pthread_attr_destroy(&attr); 68*8a272653SPeter Holm return; 69*8a272653SPeter Holm } 70*8a272653SPeter Holm if (errno == EAGAIN) { 71*8a272653SPeter Holm usleep(50); 72*8a272653SPeter Holm continue; 73*8a272653SPeter Holm } 74*8a272653SPeter Holm break; 75*8a272653SPeter Holm } 76*8a272653SPeter Holm exit(1); 77*8a272653SPeter Holm} 78*8a272653SPeter Holm 79*8a272653SPeter Holmtypedef struct { 80*8a272653SPeter Holm pthread_mutex_t mu; 81*8a272653SPeter Holm pthread_cond_t cv; 82*8a272653SPeter Holm int state; 83*8a272653SPeter Holm} event_t; 84*8a272653SPeter Holm 85*8a272653SPeter Holmstatic void event_init(event_t* ev) 86*8a272653SPeter Holm{ 87*8a272653SPeter Holm if (pthread_mutex_init(&ev->mu, 0)) 88*8a272653SPeter Holm exit(1); 89*8a272653SPeter Holm if (pthread_cond_init(&ev->cv, 0)) 90*8a272653SPeter Holm exit(1); 91*8a272653SPeter Holm ev->state = 0; 92*8a272653SPeter Holm} 93*8a272653SPeter Holm 94*8a272653SPeter Holmstatic void event_reset(event_t* ev) 95*8a272653SPeter Holm{ 96*8a272653SPeter Holm ev->state = 0; 97*8a272653SPeter Holm} 98*8a272653SPeter Holm 99*8a272653SPeter Holmstatic void event_set(event_t* ev) 100*8a272653SPeter Holm{ 101*8a272653SPeter Holm pthread_mutex_lock(&ev->mu); 102*8a272653SPeter Holm if (ev->state) 103*8a272653SPeter Holm exit(1); 104*8a272653SPeter Holm ev->state = 1; 105*8a272653SPeter Holm pthread_mutex_unlock(&ev->mu); 106*8a272653SPeter Holm pthread_cond_broadcast(&ev->cv); 107*8a272653SPeter Holm} 108*8a272653SPeter Holm 109*8a272653SPeter Holmstatic void event_wait(event_t* ev) 110*8a272653SPeter Holm{ 111*8a272653SPeter Holm pthread_mutex_lock(&ev->mu); 112*8a272653SPeter Holm while (!ev->state) 113*8a272653SPeter Holm pthread_cond_wait(&ev->cv, &ev->mu); 114*8a272653SPeter Holm pthread_mutex_unlock(&ev->mu); 115*8a272653SPeter Holm} 116*8a272653SPeter Holm 117*8a272653SPeter Holmstatic int event_isset(event_t* ev) 118*8a272653SPeter Holm{ 119*8a272653SPeter Holm pthread_mutex_lock(&ev->mu); 120*8a272653SPeter Holm int res = ev->state; 121*8a272653SPeter Holm pthread_mutex_unlock(&ev->mu); 122*8a272653SPeter Holm return res; 123*8a272653SPeter Holm} 124*8a272653SPeter Holm 125*8a272653SPeter Holmstatic int event_timedwait(event_t* ev, uint64_t timeout) 126*8a272653SPeter Holm{ 127*8a272653SPeter Holm uint64_t start = current_time_ms(); 128*8a272653SPeter Holm uint64_t now = start; 129*8a272653SPeter Holm pthread_mutex_lock(&ev->mu); 130*8a272653SPeter Holm for (;;) { 131*8a272653SPeter Holm if (ev->state) 132*8a272653SPeter Holm break; 133*8a272653SPeter Holm uint64_t remain = timeout - (now - start); 134*8a272653SPeter Holm struct timespec ts; 135*8a272653SPeter Holm ts.tv_sec = remain / 1000; 136*8a272653SPeter Holm ts.tv_nsec = (remain % 1000) * 1000 * 1000; 137*8a272653SPeter Holm pthread_cond_timedwait(&ev->cv, &ev->mu, &ts); 138*8a272653SPeter Holm now = current_time_ms(); 139*8a272653SPeter Holm if (now - start > timeout) 140*8a272653SPeter Holm break; 141*8a272653SPeter Holm } 142*8a272653SPeter Holm int res = ev->state; 143*8a272653SPeter Holm pthread_mutex_unlock(&ev->mu); 144*8a272653SPeter Holm return res; 145*8a272653SPeter Holm} 146*8a272653SPeter Holm 147*8a272653SPeter Holmstruct thread_t { 148*8a272653SPeter Holm int created, call; 149*8a272653SPeter Holm event_t ready, done; 150*8a272653SPeter Holm}; 151*8a272653SPeter Holm 152*8a272653SPeter Holmstatic struct thread_t threads[16]; 153*8a272653SPeter Holmstatic void execute_call(int call); 154*8a272653SPeter Holmstatic int running; 155*8a272653SPeter Holm 156*8a272653SPeter Holmstatic void* thr(void* arg) 157*8a272653SPeter Holm{ 158*8a272653SPeter Holm struct thread_t* th = (struct thread_t*)arg; 159*8a272653SPeter Holm for (;;) { 160*8a272653SPeter Holm event_wait(&th->ready); 161*8a272653SPeter Holm event_reset(&th->ready); 162*8a272653SPeter Holm execute_call(th->call); 163*8a272653SPeter Holm __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); 164*8a272653SPeter Holm event_set(&th->done); 165*8a272653SPeter Holm } 166*8a272653SPeter Holm return 0; 167*8a272653SPeter Holm} 168*8a272653SPeter Holm 169*8a272653SPeter Holmstatic void loop(void) 170*8a272653SPeter Holm{ 171*8a272653SPeter Holm int i, call, thread; 172*8a272653SPeter Holm for (call = 0; call < 7; call++) { 173*8a272653SPeter Holm for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); 174*8a272653SPeter Holm thread++) { 175*8a272653SPeter Holm struct thread_t* th = &threads[thread]; 176*8a272653SPeter Holm if (!th->created) { 177*8a272653SPeter Holm th->created = 1; 178*8a272653SPeter Holm event_init(&th->ready); 179*8a272653SPeter Holm event_init(&th->done); 180*8a272653SPeter Holm event_set(&th->done); 181*8a272653SPeter Holm thread_start(thr, th); 182*8a272653SPeter Holm } 183*8a272653SPeter Holm if (!event_isset(&th->done)) 184*8a272653SPeter Holm continue; 185*8a272653SPeter Holm event_reset(&th->done); 186*8a272653SPeter Holm th->call = call; 187*8a272653SPeter Holm __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); 188*8a272653SPeter Holm event_set(&th->ready); 189*8a272653SPeter Holm event_timedwait(&th->done, 45); 190*8a272653SPeter Holm break; 191*8a272653SPeter Holm } 192*8a272653SPeter Holm } 193*8a272653SPeter Holm for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) 194*8a272653SPeter Holm sleep_ms(1); 195*8a272653SPeter Holm} 196*8a272653SPeter Holm 197*8a272653SPeter Holmuint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; 198*8a272653SPeter Holm 199*8a272653SPeter Holmvoid execute_call(int call) 200*8a272653SPeter Holm{ 201*8a272653SPeter Holm intptr_t res; 202*8a272653SPeter Holm switch (call) { 203*8a272653SPeter Holm case 0: 204*8a272653SPeter Holm memcpy((void*)0x20000000, "./file0\000", 8); 205*8a272653SPeter Holm res = syscall(SYS_open, 0x20000000ul, 0x40000400000002c2ul, 0ul); 206*8a272653SPeter Holm if (res != -1) 207*8a272653SPeter Holm r[0] = res; 208*8a272653SPeter Holm break; 209*8a272653SPeter Holm case 1: 210*8a272653SPeter Holm res = syscall(SYS_socket, 0x1cul, 1ul, 0ul); 211*8a272653SPeter Holm if (res != -1) 212*8a272653SPeter Holm r[1] = res; 213*8a272653SPeter Holm break; 214*8a272653SPeter Holm case 2: 215*8a272653SPeter Holm syscall(SYS_listen, r[1], 0); 216*8a272653SPeter Holm break; 217*8a272653SPeter Holm case 3: 218*8a272653SPeter Holm syscall(SYS_close, r[0]); 219*8a272653SPeter Holm break; 220*8a272653SPeter Holm case 4: 221*8a272653SPeter Holm syscall(SYS_accept, r[1], 0ul, 0ul); 222*8a272653SPeter Holm break; 223*8a272653SPeter Holm case 5: 224*8a272653SPeter Holm res = syscall(SYS_dup2, r[0], r[1]); 225*8a272653SPeter Holm if (res != -1) 226*8a272653SPeter Holm r[2] = res; 227*8a272653SPeter Holm break; 228*8a272653SPeter Holm case 6: 229*8a272653SPeter Holm syscall(SYS_mmap, 0x20ffd000ul, 0x1000ul, 0ul, 0x10ul, r[2], 0ul); 230*8a272653SPeter Holm break; 231*8a272653SPeter Holm } 232*8a272653SPeter Holm} 233*8a272653SPeter Holmint main(void) 234*8a272653SPeter Holm{ 235*8a272653SPeter Holm syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x1012ul, -1, 0ul); 236*8a272653SPeter Holm loop(); 237*8a272653SPeter Holm return 0; 238*8a272653SPeter Holm} 239*8a272653SPeter HolmEOF 240*8a272653SPeter Holmmycc -o /tmp/syzkaller1 -Wall -Wextra -O2 /tmp/syzkaller1.c -lpthread || 241*8a272653SPeter Holm exit 1 242*8a272653SPeter Holm 243*8a272653SPeter Holm(cd /tmp; ./syzkaller1) 244*8a272653SPeter Holm 245*8a272653SPeter Holmrm -f /tmp/syzkaller1 /tmp/syzkaller1.c /tmp/syzkaller1.core 246*8a272653SPeter Holmexit 0 247