1#!/bin/sh 2 3# panic: Bad tailq NEXT(0xfffffe0079608f00->tqh_last) != NULL 4# cpuid = 20 5# time = 1616404997 6# KDB: stack backtrace: 7# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe01af6d8580 8# vpanic() at vpanic+0x181/frame 0xfffffe01af6d85d0 9# panic() at panic+0x43/frame 0xfffffe01af6d8630 10# sctp_ss_default_add() at sctp_ss_default_add+0xd7/frame 0xfffffe01af6d8660 11# sctp_lower_sosend() at sctp_lower_sosend+0x3b24/frame 0xfffffe01af6d8830 12# sctp_sosend() at sctp_sosend+0x344/frame 0xfffffe01af6d8950 13# sosend() at sosend+0x66/frame 0xfffffe01af6d8980 14# kern_sendit() at kern_sendit+0x1ec/frame 0xfffffe01af6d8a10 15# sendit() at sendit+0x1db/frame 0xfffffe01af6d8a60 16# sys_sendmsg() at sys_sendmsg+0x61/frame 0xfffffe01af6d8ac0 17# amd64_syscall() at amd64_syscall+0x147/frame 0xfffffe01af6d8bf0 18# fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe01af6d8bf0 19# --- syscall (0, FreeBSD ELF64, nosys), rip = 0x8003b042a, rsp = 0x7fffdffdcf68, rbp = 0x7fffdffdcf90 --- 20# KDB: enter: panic 21# [ thread pid 7402 tid 730532 ] 22# Stopped at kdb_enter+0x37: movq $0,0x1286f8e(%rip) 23# db> x/s version 24# version: FreeBSD 14.0-CURRENT #0 main-n245565-25bfa448602: Mon Mar 22 09:13:03 CET 2021 25# pho@t2.osted.lan:/usr/src/sys/amd64/compile/PHO\012 26# db> 27 28[ `uname -p` != "amd64" ] && exit 0 29 30. ../default.cfg 31kldstat -v | grep -q sctp || kldload sctp.ko 32 33cat > /tmp/syzkaller31.c <<EOF 34// https://syzkaller.appspot.com/bug?id=57c78914e36b822eaa173cfd681e4f63822e0844 35// autogenerated by syzkaller (https://github.com/google/syzkaller) 36// Reported-by: syzbot+ed6e8de942351d0309f4@syzkaller.appspotmail.com 37 38#define _GNU_SOURCE 39 40#include <sys/types.h> 41 42#include <errno.h> 43#include <pthread.h> 44#include <pwd.h> 45#include <signal.h> 46#include <stdarg.h> 47#include <stdbool.h> 48#include <stdint.h> 49#include <stdio.h> 50#include <stdlib.h> 51#include <string.h> 52#include <sys/endian.h> 53#include <sys/syscall.h> 54#include <sys/wait.h> 55#include <time.h> 56#include <unistd.h> 57 58static void kill_and_wait(int pid, int* status) 59{ 60 kill(pid, SIGKILL); 61 while (waitpid(-1, status, 0) != pid) { 62 } 63} 64 65static void sleep_ms(uint64_t ms) 66{ 67 usleep(ms * 1000); 68} 69 70static uint64_t current_time_ms(void) 71{ 72 struct timespec ts; 73 if (clock_gettime(CLOCK_MONOTONIC, &ts)) 74 exit(1); 75 return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; 76} 77 78static void thread_start(void* (*fn)(void*), void* arg) 79{ 80 pthread_t th; 81 pthread_attr_t attr; 82 pthread_attr_init(&attr); 83 pthread_attr_setstacksize(&attr, 128 << 10); 84 int i = 0; 85 for (; i < 100; i++) { 86 if (pthread_create(&th, &attr, fn, arg) == 0) { 87 pthread_attr_destroy(&attr); 88 return; 89 } 90 if (errno == EAGAIN) { 91 usleep(50); 92 continue; 93 } 94 break; 95 } 96 exit(1); 97} 98 99typedef struct { 100 pthread_mutex_t mu; 101 pthread_cond_t cv; 102 int state; 103} event_t; 104 105static void event_init(event_t* ev) 106{ 107 if (pthread_mutex_init(&ev->mu, 0)) 108 exit(1); 109 if (pthread_cond_init(&ev->cv, 0)) 110 exit(1); 111 ev->state = 0; 112} 113 114static void event_reset(event_t* ev) 115{ 116 ev->state = 0; 117} 118 119static void event_set(event_t* ev) 120{ 121 pthread_mutex_lock(&ev->mu); 122 if (ev->state) 123 exit(1); 124 ev->state = 1; 125 pthread_mutex_unlock(&ev->mu); 126 pthread_cond_broadcast(&ev->cv); 127} 128 129static void event_wait(event_t* ev) 130{ 131 pthread_mutex_lock(&ev->mu); 132 while (!ev->state) 133 pthread_cond_wait(&ev->cv, &ev->mu); 134 pthread_mutex_unlock(&ev->mu); 135} 136 137static int event_isset(event_t* ev) 138{ 139 pthread_mutex_lock(&ev->mu); 140 int res = ev->state; 141 pthread_mutex_unlock(&ev->mu); 142 return res; 143} 144 145static int event_timedwait(event_t* ev, uint64_t timeout) 146{ 147 uint64_t start = current_time_ms(); 148 uint64_t now = start; 149 pthread_mutex_lock(&ev->mu); 150 for (;;) { 151 if (ev->state) 152 break; 153 uint64_t remain = timeout - (now - start); 154 struct timespec ts; 155 ts.tv_sec = remain / 1000; 156 ts.tv_nsec = (remain % 1000) * 1000 * 1000; 157 pthread_cond_timedwait(&ev->cv, &ev->mu, &ts); 158 now = current_time_ms(); 159 if (now - start > timeout) 160 break; 161 } 162 int res = ev->state; 163 pthread_mutex_unlock(&ev->mu); 164 return res; 165} 166 167struct thread_t { 168 int created, call; 169 event_t ready, done; 170}; 171 172static struct thread_t threads[16]; 173static void execute_call(int call); 174static int running; 175 176static void* thr(void* arg) 177{ 178 struct thread_t* th = (struct thread_t*)arg; 179 for (;;) { 180 event_wait(&th->ready); 181 event_reset(&th->ready); 182 execute_call(th->call); 183 __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); 184 event_set(&th->done); 185 } 186 return 0; 187} 188 189static void execute_one(void) 190{ 191 int i, call, thread; 192 int collide = 0; 193again: 194 for (call = 0; call < 3; call++) { 195 for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); 196 thread++) { 197 struct thread_t* th = &threads[thread]; 198 if (!th->created) { 199 th->created = 1; 200 event_init(&th->ready); 201 event_init(&th->done); 202 event_set(&th->done); 203 thread_start(thr, th); 204 } 205 if (!event_isset(&th->done)) 206 continue; 207 event_reset(&th->done); 208 th->call = call; 209 __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); 210 event_set(&th->ready); 211 if (collide && (call % 2) == 0) 212 break; 213 event_timedwait(&th->done, 50); 214 break; 215 } 216 } 217 for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) 218 sleep_ms(1); 219 if (!collide) { 220 collide = 1; 221 goto again; 222 } 223} 224 225static void execute_one(void); 226 227#define WAIT_FLAGS 0 228 229static void loop(void) 230{ 231 int iter __unused = 0; 232 for (;; iter++) { 233 int pid = fork(); 234 if (pid < 0) 235 exit(1); 236 if (pid == 0) { 237 execute_one(); 238 exit(0); 239 } 240 int status = 0; 241 uint64_t start = current_time_ms(); 242 for (;;) { 243 if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) 244 break; 245 sleep_ms(1); 246 if (current_time_ms() - start < 5000) { 247 continue; 248 } 249 kill_and_wait(pid, &status); 250 break; 251 } 252 } 253} 254 255uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; 256 257void execute_call(int call) 258{ 259 intptr_t res = 0; 260 switch (call) { 261 case 0: 262 res = syscall(SYS_socket, 2ul, 5ul, 0x84); 263 if (res != -1) 264 r[0] = res; 265 break; 266 case 1: 267 res = syscall(SYS_fcntl, r[0], 0ul, r[0]); 268 if (res != -1) 269 r[1] = res; 270 break; 271 case 2: 272 *(uint64_t*)0x20000040 = 0x20000000; 273 *(uint8_t*)0x20000000 = 0x1c; 274 *(uint8_t*)0x20000001 = 0x1c; 275 *(uint16_t*)0x20000002 = htobe16(0x4e22); 276 *(uint32_t*)0x20000004 = 0; 277 *(uint8_t*)0x20000008 = 0; 278 *(uint8_t*)0x20000009 = 0; 279 *(uint8_t*)0x2000000a = 0; 280 *(uint8_t*)0x2000000b = 0; 281 *(uint8_t*)0x2000000c = 0; 282 *(uint8_t*)0x2000000d = 0; 283 *(uint8_t*)0x2000000e = 0; 284 *(uint8_t*)0x2000000f = 0; 285 *(uint8_t*)0x20000010 = 0; 286 *(uint8_t*)0x20000011 = 0; 287 *(uint8_t*)0x20000012 = -1; 288 *(uint8_t*)0x20000013 = -1; 289 *(uint32_t*)0x20000014 = htobe32(0x203); 290 *(uint32_t*)0x20000018 = 0; 291 *(uint32_t*)0x20000048 = 0x1c; 292 *(uint64_t*)0x20000050 = 0x20000100; 293 *(uint64_t*)0x20000100 = 0x20000080; 294 memcpy((void*)0x20000080, "\000", 1); 295 *(uint64_t*)0x20000108 = 1; 296 *(uint32_t*)0x20000058 = 1; 297 *(uint64_t*)0x20000060 = 0x20000200; 298 memcpy( 299 (void*)0x20000200, 300 "\x1c\x00\x00\x00\x84\x00\x00\x00\x01\x00\x00\x00\x40\x08\xec\x70\xa0", 301 17); 302 *(uint32_t*)0x20000068 = 0x1c; 303 *(uint32_t*)0x2000006c = 0; 304 syscall(SYS_sendmsg, r[1], 0x20000040ul, 0ul); 305 break; 306 } 307} 308int main(void) 309{ 310 syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); 311 loop(); 312 return 0; 313} 314EOF 315mycc -o /tmp/syzkaller31 -Wall -Wextra -O0 /tmp/syzkaller31.c -lpthread || 316 exit 1 317 318(cd ../testcases/swap; ./swap -t 1m -i 20 -h > /dev/null 2>&1) & 319(cd /tmp; timeout 3m ./syzkaller31) 320while pkill swap; do :; done 321wait 322 323rm -rf /tmp/syzkaller31 /tmp/syzkaller31.c /tmp/syzkaller.* 324exit 0 325