1#!/bin/sh 2 3# panic: freevnode: cannot lock vp 0xfffffe01634e4de0 for pollinfo destroy 4# cpuid = 7 5# time = 1762875612 6# KDB: stack backtrace: 7# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00ffce8bd0 8# vpanic() at vpanic+0x136/frame 0xfffffe00ffce8d00 9# panic() at panic+0x43/frame 0xfffffe00ffce8d60 10# freevnode() at freevnode+0x536/frame 0xfffffe00ffce8dc0 11# vput_final() at vput_final+0x96/frame 0xfffffe00ffce8e10 12# inotify_reap() at inotify_reap+0x6e/frame 0xfffffe00ffce8e40 13# taskqueue_run_locked() at taskqueue_run_locked+0x1c2/frame 0xfffffe00ffce8ec0 14# taskqueue_thread_loop() at taskqueue_thread_loop+0xd3/frame 0xfffffe00ffce8ef0 15# fork_exit() at fork_exit+0x82/frame 0xfffffe00ffce8f30 16# fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00ffce8f30 17# --- trap 0, rip = 0, rsp = 0, rbp = 0 --- 18# KDB: enter: panic 19# [ thread pid 0 tid 100045 ] 20# Stopped at $0,0x12129d2(%rip) 21# db> x/s version 22# version: FreeBSD 16.0-CURRENT #0 main-n281796-e1c6f4cb9bd2-dirty: Tue Nov 11 10:53:40 CET 2025 23# pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO 24# db> 25 26[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1 27 28. ../default.cfg 29set -u 30prog=$(basename "$0" .sh) 31cat > /tmp/$prog.c <<EOF 32// https://syzkaller.appspot.com/bug?id=8a22955cd068cf454dd8062d24e826c72b1c4542 33// autogenerated by syzkaller (https://github.com/google/syzkaller) 34// syzbot+6676b3ff282d590b0fb3@syzkaller.appspotmail.com 35 36#define _GNU_SOURCE 37 38#include <sys/types.h> 39 40#include <dirent.h> 41#include <errno.h> 42#include <pwd.h> 43#include <setjmp.h> 44#include <signal.h> 45#include <stdarg.h> 46#include <stdbool.h> 47#include <stdint.h> 48#include <stdio.h> 49#include <stdlib.h> 50#include <string.h> 51#include <sys/endian.h> 52#include <sys/stat.h> 53#include <sys/syscall.h> 54#include <sys/wait.h> 55#include <time.h> 56#include <unistd.h> 57 58#ifndef SYS___specialfd 59#define SYS___specialfd 577 60#endif 61#ifndef SYS_inotify_add_watch_at 62#define SYS_inotify_add_watch_at 593 63#endif 64 65static __thread int clone_ongoing; 66static __thread int skip_segv; 67static __thread jmp_buf segv_env; 68 69static void segv_handler(int sig, siginfo_t* info, void* ctx __unused) 70{ 71 if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { 72 exit(sig); 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 int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; 78 int valid = addr < prog_start || addr > prog_end; 79 if (sig == SIGBUS) 80 valid = 1; 81 if (skip && valid) { 82 _longjmp(segv_env, 1); 83 } 84 exit(sig); 85} 86 87static void install_segv_handler(void) 88{ 89 struct sigaction sa; 90 memset(&sa, 0, sizeof(sa)); 91 sa.sa_sigaction = segv_handler; 92 sa.sa_flags = SA_NODEFER | SA_SIGINFO; 93 sigaction(SIGSEGV, &sa, NULL); 94 sigaction(SIGBUS, &sa, NULL); 95} 96 97#define NONFAILING(...) \ 98 ({ \ 99 int ok = 1; \ 100 __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ 101 if (_setjmp(segv_env) == 0) { \ 102 __VA_ARGS__; \ 103 } else \ 104 ok = 0; \ 105 __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ 106 ok; \ 107 }) 108 109static void kill_and_wait(int pid, int* status) 110{ 111 kill(pid, SIGKILL); 112 while (waitpid(-1, status, 0) != pid) { 113 } 114} 115 116static void sleep_ms(uint64_t ms) 117{ 118 usleep(ms * 1000); 119} 120 121static uint64_t current_time_ms(void) 122{ 123 struct timespec ts; 124 if (clock_gettime(CLOCK_MONOTONIC, &ts)) 125 exit(1); 126 return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; 127} 128 129static void use_temporary_dir(void) 130{ 131 char tmpdir_template[] = "./syzkaller.XXXXXX"; 132 char* tmpdir = mkdtemp(tmpdir_template); 133 if (!tmpdir) 134 exit(1); 135 if (chmod(tmpdir, 0777)) 136 exit(1); 137 if (chdir(tmpdir)) 138 exit(1); 139} 140 141static void reset_flags(const char* filename) 142{ 143 struct stat st; 144 if (lstat(filename, &st)) 145 exit(1); 146 st.st_flags &= ~(SF_NOUNLINK | UF_NOUNLINK | SF_IMMUTABLE | UF_IMMUTABLE | 147 SF_APPEND | UF_APPEND); 148 if (lchflags(filename, st.st_flags)) 149 exit(1); 150} 151static void __attribute__((noinline)) remove_dir(const char* dir) 152{ 153 DIR* dp = opendir(dir); 154 if (dp == NULL) { 155 if (errno == EACCES) { 156 if (rmdir(dir)) 157 exit(1); 158 return; 159 } 160 exit(1); 161 } 162 struct dirent* ep = 0; 163 while ((ep = readdir(dp))) { 164 if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) 165 continue; 166 char filename[FILENAME_MAX]; 167 snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); 168 struct stat st; 169 if (lstat(filename, &st)) 170 exit(1); 171 if (S_ISDIR(st.st_mode)) { 172 remove_dir(filename); 173 continue; 174 } 175 if (unlink(filename)) { 176 if (errno == EPERM) { 177 reset_flags(filename); 178 reset_flags(dir); 179 if (unlink(filename) == 0) 180 continue; 181 } 182 exit(1); 183 } 184 } 185 closedir(dp); 186 while (rmdir(dir)) { 187 if (errno == EPERM) { 188 reset_flags(dir); 189 if (rmdir(dir) == 0) 190 break; 191 } 192 exit(1); 193 } 194} 195 196static void execute_one(void); 197 198#define WAIT_FLAGS 0 199 200static void loop(void) 201{ 202 int iter = 0; 203 for (;; iter++) { 204 char cwdbuf[32]; 205 sprintf(cwdbuf, "./%d", iter); 206 if (mkdir(cwdbuf, 0777)) 207 exit(1); 208 int pid = fork(); 209 if (pid < 0) 210 exit(1); 211 if (pid == 0) { 212 if (chdir(cwdbuf)) 213 exit(1); 214 execute_one(); 215 exit(0); 216 } 217 int status = 0; 218 uint64_t start = current_time_ms(); 219 for (;;) { 220 sleep_ms(10); 221 if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) 222 break; 223 if (current_time_ms() - start < 5000) 224 continue; 225 kill_and_wait(pid, &status); 226 break; 227 } 228 remove_dir(cwdbuf); 229 } 230} 231 232uint64_t r[1] = {0xffffffffffffffff}; 233 234void execute_one(void) 235{ 236 intptr_t res = 0; 237 if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { 238 } 239 // openat\$evdev arguments: [ 240 // fd: const = 0xffffffffffffff9c (8 bytes) 241 // file: ptr[in, buffer] { 242 // buffer: {2f 64 65 76 2f 69 6e 70 75 74 2f 65 76 65 6e 74 4e 00} 243 // (length 0x12) 244 // } 245 // flags: open_flags = 0x100 (8 bytes) 246 // mode: const = 0x0 (8 bytes) 247 // ] 248 // returns fd_evdev 249 NONFAILING(memcpy((void*)0x200000000040, "/dev/input/eventN\000", 18)); 250 syscall(SYS_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000040ul, 251 /*flags=O_NOFOLLOW*/ 0x100ul, /*mode=*/0ul); 252 // kqueue arguments: [ 253 // ] 254 // returns kqueue 255 syscall(SYS_kqueue); 256 // pipe2 arguments: [ 257 // pipefd: ptr[out, pipefd] { 258 // pipefd { 259 // rfd: fd (resource) 260 // wfd: fd (resource) 261 // } 262 // } 263 // flags: pipe_flags = 0x0 (8 bytes) 264 // ] 265 syscall(SYS_pipe2, /*pipefd=*/0x200000000480ul, /*flags=*/0ul); 266 // socket\$unix arguments: [ 267 // domain: const = 0x1 (8 bytes) 268 // type: unix_socket_type = 0x5 (8 bytes) 269 // proto: const = 0x0 (1 bytes) 270 // ] 271 // returns sock_unix 272 syscall(SYS_socket, /*domain=*/1ul, /*type=SOCK_SEQPACKET*/ 5ul, /*proto=*/0); 273 // kqueue arguments: [ 274 // ] 275 // returns kqueue 276 syscall(SYS_kqueue); 277 // mprotect arguments: [ 278 // addr: VMA[0x2000] 279 // len: len = 0x2000 (8 bytes) 280 // prot: mmap_prot = 0x5 (8 bytes) 281 // ] 282 syscall(SYS_mprotect, /*addr=*/0x200000000000ul, /*len=*/0x2000ul, 283 /*prot=PROT_READ|PROT_EXEC*/ 5ul); 284 // symlink arguments: [ 285 // old: ptr[in, buffer] { 286 // buffer: {2e 00} (length 0x2) 287 // } 288 // new: ptr[in, buffer] { 289 // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) 290 // } 291 // ] 292 NONFAILING(memcpy((void*)0x200000000000, ".\000", 2)); 293 NONFAILING(memcpy((void*)0x200000000040, "./file0\000", 8)); 294 syscall(SYS_symlink, /*old=*/0x200000000000ul, /*new=*/0x200000000040ul); 295 // __specialfd\$inotify arguments: [ 296 // type: const = 0x2 (8 bytes) 297 // req: ptr[in, specialfd_inotify] { 298 // specialfd_inotify { 299 // flags: inotify_flags = 0x0 (4 bytes) 300 // } 301 // } 302 // len: len = 0x4 (8 bytes) 303 // ] 304 // returns fd_inotify 305 NONFAILING(*(uint32_t*)0x200000000180 = 0); 306 res = syscall(SYS___specialfd, /*type=*/2ul, /*req=*/0x200000000180ul, 307 /*len=*/4ul); 308 if (res != -1) 309 r[0] = res; 310 // inotify_add_watch_at arguments: [ 311 // fd: fd_inotify (resource) 312 // dfd: fd_dir (resource) 313 // file: ptr[in, buffer] { 314 // buffer: {2e 2f 66 69 6c 65 30 61 61 61 61 61 61 61 61 61 61 61 61 61 315 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 316 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 317 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 318 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 319 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 320 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 321 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 322 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 323 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 324 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 2f 66 325 // 69 6c 65 30 00} (length 0xff) 326 // } 327 // mask: inotify_mask = 0x82000204 (8 bytes) 328 // ] 329 // returns inotifydesc 330 NONFAILING( 331 memcpy((void*)0x200000000040, 332 "./" 333 "file0aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" 334 "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" 335 "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" 336 "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/file0\000", 337 255)); 338 syscall(SYS_inotify_add_watch_at, /*fd=*/r[0], /*dfd=*/(intptr_t)-1, 339 /*file=*/0x200000000040ul, 340 /*mask=IN_ONESHOT|IN_DONT_FOLLOW|IN_DELETE|IN_ATTRIB*/ 0x82000204ul); 341 // unlink arguments: [ 342 // path: ptr[in, buffer] { 343 // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) 344 // } 345 // ] 346 NONFAILING(memcpy((void*)0x200000000040, "./file0\000", 8)); 347 syscall(SYS_unlink, /*path=*/0x200000000040ul); 348} 349int main(void) 350{ 351 syscall(SYS_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, 352 /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, 353 /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x1012ul, 354 /*fd=*/(intptr_t)-1, /*offset=*/0ul); 355 const char* reason; 356 (void)reason; 357 install_segv_handler(); 358 use_temporary_dir(); 359 loop(); 360 return 0; 361} 362EOF 363mycc -o /tmp/$prog -Wall -Wextra -O0 /tmp/$prog.c -lpthread || exit 1 364 365(cd ../testcases/swap; ./swap -t 3m -i 30 -l 100 > /dev/null 2>&1) & 366sleep 5 367 368work=/tmp/$prog.dir 369rm -rf $work 370mkdir $work 371cd /tmp/$prog.dir 372for i in `jot 30`; do 373 ( 374 mkdir d$i 375 cd d$i 376 timeout 3m /tmp/$prog > /dev/null 2>&1 & 377 ) 378done 379while pgrep -q $prog; do sleep 2; done 380while pkill swap; do :; done 381wait 382 383rm -rf /tmp/$prog /tmp/$prog.c /tmp/$prog.core /tmp/syzkaller.?????? $work 384exit 0 385