1#!/bin/sh 2 3# Fatal trap 9: general protection fault while in kernel mode 4# cpuid = 10; apic id = 0a 5# instruction pointer = 0x20:0xffffffff80db1fd9 6# stack pointer = 0x0:0xfffffe00e2240660 7# frame pointer = 0x0:0xfffffe00e2240830 8# code segment = base 0x0, limit 0xfffff, type 0x1b 9# = DPL 0, pres 1, long 1, def32 0, gran 1 10# processor eflags = interrupt enabled, resume, IOPL = 0 11# current process = 29524 (syzkaller16) 12# trap number = 9 13# panic: general protection fault 14# cpuid = 10 15# time = 1592652215 16# KDB: stack backtrace: 17# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00e2240370 18# vpanic() at vpanic+0x182/frame 0xfffffe00e22403c0 19# panic() at panic+0x43/frame 0xfffffe00e2240420 20# trap_fatal() at trap_fatal+0x387/frame 0xfffffe00e2240480 21# trap() at trap+0x80/frame 0xfffffe00e2240590 22# calltrap() at calltrap+0x8/frame 0xfffffe00e2240590 23# --- trap 0x9, rip = 0xffffffff80db1fd9, rsp = 0xfffffe00e2240660, rbp = 0xfffffe00e2240830 --- 24# sctp_lower_sosend() at sctp_lower_sosend+0x21b9/frame 0xfffffe00e2240830 25# sctp_sosend() at sctp_sosend+0x346/frame 0xfffffe00e2240950 26# sosend() at sosend+0x66/frame 0xfffffe00e2240980 27# kern_sendit() at kern_sendit+0x246/frame 0xfffffe00e2240a20 28# sendit() at sendit+0x1d8/frame 0xfffffe00e2240a70 29# sys_sendto() at sys_sendto+0x4d/frame 0xfffffe00e2240ac0 30# ia32_syscall() at ia32_syscall+0x150/frame 0xfffffe00e2240bf0 31# int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0xfbffcf8c 32# db> x/s version 33# version: FreeBSD 13.0-CURRENT #0 r362431: Sat Jun 20 09:52:53 CEST 2020 34# pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO 35# db> 36 37[ `uname -p` != "amd64" ] && exit 0 38 39. ../default.cfg 40kldstat -v | grep -q sctp || kldload sctp.ko 41cat > /tmp/syzkaller16.c <<EOF 42// https://syzkaller.appspot.com/bug?id=4b11a1abc41d0a67736ef9a7506ab3ec7e378102 43// autogenerated by syzkaller (https://github.com/google/syzkaller) 44// Reported-by: syzbot+bc02585076c3cc977f9b@syzkaller.appspotmail.com 45 46#define _GNU_SOURCE 47 48#include <sys/types.h> 49 50#include <errno.h> 51#include <pthread.h> 52#include <pwd.h> 53#include <setjmp.h> 54#include <signal.h> 55#include <stdarg.h> 56#include <stdbool.h> 57#include <stdint.h> 58#include <stdio.h> 59#include <stdlib.h> 60#include <string.h> 61#include <sys/endian.h> 62#include <sys/syscall.h> 63#include <sys/wait.h> 64#include <time.h> 65#include <unistd.h> 66 67static unsigned long long procid; 68 69static __thread int skip_segv; 70static __thread jmp_buf segv_env; 71 72static void segv_handler(int sig, siginfo_t* info, void* ctx __unused) 73{ 74 uintptr_t addr = (uintptr_t)info->si_addr; 75 const uintptr_t prog_start = 1 << 20; 76 const uintptr_t prog_end = 100 << 20; 77 if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && 78 (addr < prog_start || addr > prog_end)) { 79 _longjmp(segv_env, 1); 80 } 81 exit(sig); 82} 83 84static void install_segv_handler(void) 85{ 86 struct sigaction sa; 87 memset(&sa, 0, sizeof(sa)); 88 sa.sa_sigaction = segv_handler; 89 sa.sa_flags = SA_NODEFER | SA_SIGINFO; 90 sigaction(SIGSEGV, &sa, NULL); 91 sigaction(SIGBUS, &sa, NULL); 92} 93 94#define NONFAILING(...) \ 95 { \ 96 __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ 97 if (_setjmp(segv_env) == 0) { \ 98 __VA_ARGS__; \ 99 } \ 100 __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ 101 } 102 103static void kill_and_wait(int pid, int* status) 104{ 105 kill(pid, SIGKILL); 106 while (waitpid(-1, status, 0) != pid) { 107 } 108} 109 110static void sleep_ms(uint64_t ms) 111{ 112 usleep(ms * 1000); 113} 114 115static uint64_t current_time_ms(void) 116{ 117 struct timespec ts; 118 if (clock_gettime(CLOCK_MONOTONIC, &ts)) 119 exit(1); 120 return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; 121} 122 123static void thread_start(void* (*fn)(void*), void* arg) 124{ 125 pthread_t th; 126 pthread_attr_t attr; 127 pthread_attr_init(&attr); 128 pthread_attr_setstacksize(&attr, 128 << 10); 129 int i; 130 for (i = 0; i < 100; i++) { 131 if (pthread_create(&th, &attr, fn, arg) == 0) { 132 pthread_attr_destroy(&attr); 133 return; 134 } 135 if (errno == EAGAIN) { 136 usleep(50); 137 continue; 138 } 139 break; 140 } 141 exit(1); 142} 143 144typedef struct { 145 pthread_mutex_t mu; 146 pthread_cond_t cv; 147 int state; 148} event_t; 149 150static void event_init(event_t* ev) 151{ 152 if (pthread_mutex_init(&ev->mu, 0)) 153 exit(1); 154 if (pthread_cond_init(&ev->cv, 0)) 155 exit(1); 156 ev->state = 0; 157} 158 159static void event_reset(event_t* ev) 160{ 161 ev->state = 0; 162} 163 164static void event_set(event_t* ev) 165{ 166 pthread_mutex_lock(&ev->mu); 167 if (ev->state) 168 exit(1); 169 ev->state = 1; 170 pthread_mutex_unlock(&ev->mu); 171 pthread_cond_broadcast(&ev->cv); 172} 173 174static void event_wait(event_t* ev) 175{ 176 pthread_mutex_lock(&ev->mu); 177 while (!ev->state) 178 pthread_cond_wait(&ev->cv, &ev->mu); 179 pthread_mutex_unlock(&ev->mu); 180} 181 182static int event_isset(event_t* ev) 183{ 184 pthread_mutex_lock(&ev->mu); 185 int res = ev->state; 186 pthread_mutex_unlock(&ev->mu); 187 return res; 188} 189 190static int event_timedwait(event_t* ev, uint64_t timeout) 191{ 192 uint64_t start = current_time_ms(); 193 uint64_t now = start; 194 pthread_mutex_lock(&ev->mu); 195 for (;;) { 196 if (ev->state) 197 break; 198 uint64_t remain = timeout - (now - start); 199 struct timespec ts; 200 ts.tv_sec = remain / 1000; 201 ts.tv_nsec = (remain % 1000) * 1000 * 1000; 202 pthread_cond_timedwait(&ev->cv, &ev->mu, &ts); 203 now = current_time_ms(); 204 if (now - start > timeout) 205 break; 206 } 207 int res = ev->state; 208 pthread_mutex_unlock(&ev->mu); 209 return res; 210} 211 212struct thread_t { 213 int created, call; 214 event_t ready, done; 215}; 216 217static struct thread_t threads[16]; 218static void execute_call(int call); 219static int running; 220 221static void* thr(void* arg) 222{ 223 struct thread_t* th = (struct thread_t*)arg; 224 for (;;) { 225 event_wait(&th->ready); 226 event_reset(&th->ready); 227 execute_call(th->call); 228 __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); 229 event_set(&th->done); 230 } 231 return 0; 232} 233 234static void execute_one(void) 235{ 236 int i, call, thread; 237 int collide = 0; 238again: 239 for (call = 0; call < 6; call++) { 240 for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); 241 thread++) { 242 struct thread_t* th = &threads[thread]; 243 if (!th->created) { 244 th->created = 1; 245 event_init(&th->ready); 246 event_init(&th->done); 247 event_set(&th->done); 248 thread_start(thr, th); 249 } 250 if (!event_isset(&th->done)) 251 continue; 252 event_reset(&th->done); 253 th->call = call; 254 __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); 255 event_set(&th->ready); 256 if (collide && (call % 2) == 0) 257 break; 258 event_timedwait(&th->done, 45); 259 break; 260 } 261 } 262 for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) 263 sleep_ms(1); 264 if (!collide) { 265 collide = 1; 266 goto again; 267 } 268} 269 270static void execute_one(void); 271 272#define WAIT_FLAGS 0 273 274static void loop(void) 275{ 276 int iter __unused; 277 for (iter = 0;; iter++) { 278 int pid = fork(); 279 if (pid < 0) 280 exit(1); 281 if (pid == 0) { 282 execute_one(); 283 exit(0); 284 } 285 int status = 0; 286 uint64_t start = current_time_ms(); 287 for (;;) { 288 if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) 289 break; 290 sleep_ms(1); 291 if (current_time_ms() - start < 5 * 1000) 292 continue; 293 kill_and_wait(pid, &status); 294 break; 295 } 296 } 297} 298 299uint64_t r[1] = {0xffffffffffffffff}; 300 301void execute_call(int call) 302{ 303 intptr_t res = 0; 304 switch (call) { 305 case 0: 306 res = syscall(SYS_socket, 0x1c, 1, 0x84); 307 if (res != -1) 308 r[0] = res; 309 break; 310 case 1: 311 NONFAILING(*(uint8_t*)0x10000000 = 0x1c); 312 NONFAILING(*(uint8_t*)0x10000001 = 0x1c); 313 NONFAILING(*(uint16_t*)0x10000002 = htobe16(0x4e22 + procid * 4)); 314 NONFAILING(*(uint32_t*)0x10000004 = 0); 315 NONFAILING(*(uint8_t*)0x10000008 = 0); 316 NONFAILING(*(uint8_t*)0x10000009 = 0); 317 NONFAILING(*(uint8_t*)0x1000000a = 0); 318 NONFAILING(*(uint8_t*)0x1000000b = 0); 319 NONFAILING(*(uint8_t*)0x1000000c = 0); 320 NONFAILING(*(uint8_t*)0x1000000d = 0); 321 NONFAILING(*(uint8_t*)0x1000000e = 0); 322 NONFAILING(*(uint8_t*)0x1000000f = 0); 323 NONFAILING(*(uint8_t*)0x10000010 = 0); 324 NONFAILING(*(uint8_t*)0x10000011 = 0); 325 NONFAILING(*(uint8_t*)0x10000012 = 0); 326 NONFAILING(*(uint8_t*)0x10000013 = 0); 327 NONFAILING(*(uint8_t*)0x10000014 = 0); 328 NONFAILING(*(uint8_t*)0x10000015 = 0); 329 NONFAILING(*(uint8_t*)0x10000016 = 0); 330 NONFAILING(*(uint8_t*)0x10000017 = 0); 331 NONFAILING(*(uint32_t*)0x10000018 = 0); 332 syscall(SYS_bind, (intptr_t)r[0], 0x10000000, 0x1c); 333 break; 334 case 2: 335 NONFAILING(*(uint8_t*)0x10000180 = 0x5f); 336 NONFAILING(*(uint8_t*)0x10000181 = 0x1c); 337 NONFAILING(*(uint16_t*)0x10000182 = htobe16(0x4e22 + procid * 4)); 338 NONFAILING(*(uint32_t*)0x10000184 = 0); 339 NONFAILING(*(uint64_t*)0x10000188 = htobe64(0)); 340 NONFAILING(*(uint64_t*)0x10000190 = htobe64(1)); 341 NONFAILING(*(uint32_t*)0x10000198 = 0); 342 syscall(SYS_connect, (intptr_t)r[0], 0x10000180, 0x1c); 343 break; 344 case 3: 345 NONFAILING(*(uint32_t*)0x100001c0 = 0x401); 346 syscall(SYS_setsockopt, (intptr_t)r[0], 0x84, 0x1b, 0x100001c0, 4); 347 break; 348 case 4: 349 NONFAILING(memcpy( 350 (void*)0x10000380, 351 "\xa3\x1b\xe1\x78\x8e\x58\x9b\x38\x59\xf3\xbb\xdd\x7e\xf7\x51\x23\x97" 352 "\x31\xb2\x90\x4a\xd0\x4e\xb7\xdc\x37\xc6\x95\xf6\x05\x5c\xa8\x36\x54" 353 "\x7e\x7b\x6c\xc3\x7d\xae\x2a\xe4\x77\x08\x94\x67\x3c\x89\x65\x93\x24" 354 "\x1c\x56\x3e\x08\x69\x05\x35\xeb\x3b\x7f\x19\x7d\xda\x44\x54\xb4\x42" 355 "\x4f\x7f\xf9\xf9\xfe\x4e\xac\xef\xa6\xd4\xb1\x61\x9d\xd9\x0b\x97\x7c" 356 "\xd9\x82\x16\xc9\x7b\x2e\xb3\x9f\x02\xde\x0f\xae\xe7\x0b\xec\xa3\x66" 357 "\x3c\x2e\x6c\xc5\x1d\xa2\xb4\x8b\x4b\x39\x49\xcc\x14\x5a\x50\x62\x0f" 358 "\xd5\x65\xb9\x7c\x5c\xa0\xea\xfc\xa4\xc9\x13\x73\x14\x16\xba\xcc\xae" 359 "\x89\xe2\x68\x01\x06\x94\x78\xa3\xee\xa8\x45\xf7\xc2\xcb\x48\x93\xe5" 360 "\x83\x52\x45\x26\xe3\xeb\x73\xa2\xe4\xf1\x11\xcf\x40\x5f\xef\x99\xc2" 361 "\xa1\xeb\x2c\x96\x70\x56\x88\xc8\xc7\x6b\xa1\x66\xd2\x23\x20\x07\x62" 362 "\x69\xd2\x1c\x52\xbb\x5e\x86\x43\x7d\x6c\x65\x44\x42\xf6\xd8\x45\xe2" 363 "\x00\x24\x00\x00\xf0\x1d\x29\xf6\xd3\x74\x83\x25\x40\x56\x50\x17\x7f" 364 "\xc3\x60\xd7\xed\xb1\xfb\x7a\x74\x38\x2b\x47\x34\x93\x9c\xee\xc9\xb0" 365 "\xbf\x7d\xc4\x19\xe2\x77\x4c\xa2\x71\x9c\x30", 366 249)); 367 NONFAILING(*(uint8_t*)0x10000140 = 0x10); 368 NONFAILING(*(uint8_t*)0x10000141 = 2); 369 NONFAILING(*(uint16_t*)0x10000142 = htobe16(0x4e22 + procid * 4)); 370 NONFAILING(*(uint32_t*)0x10000144 = htobe32(-1)); 371 NONFAILING(*(uint8_t*)0x10000148 = 0); 372 NONFAILING(*(uint8_t*)0x10000149 = 0); 373 NONFAILING(*(uint8_t*)0x1000014a = 0); 374 NONFAILING(*(uint8_t*)0x1000014b = 0); 375 NONFAILING(*(uint8_t*)0x1000014c = 0); 376 NONFAILING(*(uint8_t*)0x1000014d = 0); 377 NONFAILING(*(uint8_t*)0x1000014e = 0); 378 NONFAILING(*(uint8_t*)0x1000014f = 0); 379 syscall(SYS_sendto, (intptr_t)r[0], 0x10000380, 0xfffffcaa, 0x20000, 380 0x10000140, 0x10); 381 break; 382 case 5: 383 NONFAILING(*(uint32_t*)0x10000540 = 0); 384 NONFAILING(*(uint32_t*)0x10000544 = 0); 385 NONFAILING(*(uint32_t*)0x10000548 = 0); 386 NONFAILING(*(uint32_t*)0x1000054c = 0); 387 NONFAILING(*(uint32_t*)0x10000550 = 0); 388 NONFAILING(*(uint32_t*)0x10000554 = 0); 389 NONFAILING(*(uint32_t*)0x10000558 = 0x20008); 390 syscall(SYS_sendmsg, (intptr_t)r[0], 0x10000540, 0x100); 391 break; 392 } 393} 394int main(void) 395{ 396 syscall(SYS_mmap, 0x10000000, 0x1000000, 7, 0x1012, -1, 0); 397 install_segv_handler(); 398 for (procid = 0; procid < 4; procid++) { 399 if (fork() == 0) { 400 loop(); 401 } 402 } 403 sleep(1000000); 404 return 0; 405} 406EOF 407mycc -o /tmp/syzkaller16 -Wall -Wextra -O0 -m32 /tmp/syzkaller16.c -pthread || 408 exit 1 409 410(cd ../testcases/swap; ./swap -t 1m -i 20 -h > /dev/null 2>&1) & 411(cd /tmp; ./syzkaller16) & 412sleep 60 413pkill -9 syzkaller16 414while pkill swap; do sleep 1; done 415wait 416 417rm -f /tmp/syzkaller16 /tmp/syzkaller16.c /tmp/syzkaller16.core 418exit 0 419