1#!/bin/sh 2 3# Kernel page fault with the following non-sleepable locks held: 4# exclusive sleep mutex so_rcv (so_rcv) r = 0 (0xfffffe012b5ee300) locked @ kern/uipc_usrreq.c:1272 5# exclusive sleep mutex socket (socket) r = 0 (0xfffffe012b5ee1a8) locked @ kern/uipc_usrreq.c:1265 6# shared rw unp_link_rwlock (unp_link_rwlock) r = 0 (0xffffffff81d99640) locked @ kern/uipc_usrreq.c:1334 7# stack backtrace: 8# #0 0xffffffff80c35701 at witness_debugger+0x71 9# #1 0xffffffff80c3669d at witness_warn+0x40d 10# #2 0xffffffff8106fb90 at trap_pfault+0x80 11# #3 0xffffffff8106f1a5 at trap+0x2a5 12# #4 0xffffffff810450d8 at calltrap+0x8 13# #5 0xffffffff80bc6fcc at sendfile_iodone+0x1ac 14# #6 0xffffffff80f3d98a at vnode_pager_generic_getpages_done_async+0x3a 15# #7 0xffffffff80c8236c at bufdone+0x6c 16# #8 0xffffffff80b0c06e at g_io_deliver+0x25e 17# #9 0xffffffff80b0c06e at g_io_deliver+0x25e 18# #10 0xffffffff80b08dfd at g_disk_done+0xed 19# #11 0xffffffff803ac1f3 at dadone+0x603 20# #12 0xffffffff8037ddf2 at xpt_done_process+0x382 21# #13 0xffffffff8037fdb5 at xpt_done_td+0xf5 22# #14 0xffffffff80b85b10 at fork_exit+0x80 23# #15 0xffffffff8104611e at fork_trampoline+0xe 24# 25# 26# Fatal trap 12: page fault while in kernel mode 27# cpuid = 23; apic id = 2b 28# fault virtual address = 0x8 29# fault code = supervisor read data, page not present 30# instruction pointer = 0x20:0xffffffff80c74bc0 31# stack pointer = 0x0:0xfffffe0126b118e0 32# frame pointer = 0x0:0xfffffe0126b11920 33# code segment = base 0x0, limit 0xfffff, type 0x1b 34# = DPL 0, pres 1, long 1, def32 0, gran 1 35# processor eflags = interrupt enabled, resume, IOPL = 0 36# current process = 32 (doneq0) 37# trap number = 12 38# panic: page fault 39# cpuid = 23 40# time = 1591531029 41# KDB: stack backtrace: 42# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe0126b11590 43# vpanic() at vpanic+0x182/frame 0xfffffe0126b115e0 44# panic() at panic+0x43/frame 0xfffffe0126b11640 45# trap_fatal() at trap_fatal+0x387/frame 0xfffffe0126b116a0 46# trap_pfault() at trap_pfault+0x99/frame 0xfffffe0126b11700 47# trap() at trap+0x2a5/frame 0xfffffe0126b11810 48# calltrap() at calltrap+0x8/frame 0xfffffe0126b11810 49# --- trap 0xc, rip = 0xffffffff80c74bc0, rsp = 0xfffffe0126b118e0, rbp = 0xfffffe0126b11920 --- 50# uipc_ready() at uipc_ready+0x1f0/frame 0xfffffe0126b11920 51# sendfile_iodone() at sendfile_iodone+0x1ac/frame 0xfffffe0126b11960 52# vnode_pager_generic_getpages_done_async() at vnode_pager_generic_getpages_done_async+0x3a/frame 0xfffffe0126b11980 53# bufdone() at bufdone+0x6c/frame 0xfffffe0126b119f0 54# g_io_deliver() at g_io_deliver+0x25e/frame 0xfffffe0126b11a40 55# g_io_deliver() at g_io_deliver+0x25e/frame 0xfffffe0126b11a90 56# g_disk_done() at g_disk_done+0xed/frame 0xfffffe0126b11ad0 57# dadone() at dadone+0x603/frame 0xfffffe0126b11b20 58# xpt_done_process() at xpt_done_process+0x382/frame 0xfffffe0126b11b60 59# xpt_done_td() at xpt_done_td+0xf5/frame 0xfffffe0126b11bb0 60# fork_exit() at fork_exit+0x80/frame 0xfffffe0126b11bf0 61# fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0126b11bf0 62# --- trap 0, rip = 0, rsp = 0, rbp = 0 --- 63# KDB: enter: panic 64# [ thread pid 32 tid 100163 ] 65# Stopped at kdb_enter+0x37: movq $0,0x10c72c6(%rip) 66# db> 67 68# Reproduced on r361889 69# Fixed by r363682 70 71[ `uname -p` = "i386" ] && exit 0 72 73. ../default.cfg 74cat > /tmp/syzkaller13.c <<EOF 75// https://syzkaller.appspot.com/bug?id=8a63fce7c52d85d6fca9aca543ce5a77cdd15f25 76// autogenerated by syzkaller (https://github.com/google/syzkaller) 77// Reported-by: syzbot+6a689cc9c27bd265237a@syzkaller.appspotmail.com 78 79#define _GNU_SOURCE 80 81#include <sys/types.h> 82 83#include <dirent.h> 84#include <pwd.h> 85#include <signal.h> 86#include <stdarg.h> 87#include <stdbool.h> 88#include <stdint.h> 89#include <stdio.h> 90#include <stdlib.h> 91#include <string.h> 92#include <sys/endian.h> 93#include <sys/stat.h> 94#include <sys/syscall.h> 95#include <sys/wait.h> 96#include <time.h> 97#include <unistd.h> 98 99static unsigned long long procid; 100 101static void kill_and_wait(int pid, int* status) 102{ 103 kill(pid, SIGKILL); 104 while (waitpid(-1, status, 0) != pid) { 105 } 106} 107 108static void sleep_ms(uint64_t ms) 109{ 110 usleep(ms * 1000); 111} 112 113static uint64_t current_time_ms(void) 114{ 115 struct timespec ts; 116 if (clock_gettime(CLOCK_MONOTONIC, &ts)) 117 exit(1); 118 return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; 119} 120 121static void use_temporary_dir(void) 122{ 123 char tmpdir_template[] = "./syzkaller.XXXXXX"; 124 char* tmpdir = mkdtemp(tmpdir_template); 125 if (!tmpdir) 126 exit(1); 127 if (chmod(tmpdir, 0777)) 128 exit(1); 129 if (chdir(tmpdir)) 130 exit(1); 131} 132 133static void remove_dir(const char* dir) 134{ 135 DIR* dp; 136 struct dirent* ep; 137 dp = opendir(dir); 138 if (dp == NULL) 139 exit(1); 140 while ((ep = readdir(dp))) { 141 if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) 142 continue; 143 char filename[FILENAME_MAX]; 144 snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); 145 struct stat st; 146 if (lstat(filename, &st)) 147 exit(1); 148 if (S_ISDIR(st.st_mode)) { 149 remove_dir(filename); 150 continue; 151 } 152 if (unlink(filename)) 153 exit(1); 154 } 155 closedir(dp); 156 if (rmdir(dir)) 157 exit(1); 158} 159 160static void execute_one(void); 161 162#define WAIT_FLAGS 0 163 164static void loop(void) 165{ 166 int iter; 167 for (iter = 0;; iter++) { 168 char cwdbuf[32]; 169 sprintf(cwdbuf, "./%d", iter); 170 if (mkdir(cwdbuf, 0777)) 171 exit(1); 172 int pid = fork(); 173 if (pid < 0) 174 exit(1); 175 if (pid == 0) { 176 if (chdir(cwdbuf)) 177 exit(1); 178 execute_one(); 179 exit(0); 180 } 181 int status = 0; 182 uint64_t start = current_time_ms(); 183 for (;;) { 184 if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) 185 break; 186 sleep_ms(1); 187 if (current_time_ms() - start < 5 * 1000) 188 continue; 189 kill_and_wait(pid, &status); 190 break; 191 } 192 remove_dir(cwdbuf); 193 } 194} 195 196uint64_t r[5] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 197 0xffffffffffffffff, 0xffffffffffffffff}; 198 199void execute_one(void) 200{ 201 intptr_t res = 0; 202 memcpy((void*)0x20000100, "./file0\000", 8); 203 res = syscall(SYS_open, 0x20000100ul, 0x40000400000002c2ul, 0ul); 204 if (res != -1) 205 r[0] = res; 206 syscall(SYS_fcntl, r[0], 4ul, 0x10048ul); 207 *(uint64_t*)0x20000340 = 0x20000180; 208 *(uint64_t*)0x20000348 = 0x81700; 209 syscall(SYS_writev, r[0], 0x20000340ul, 0x1000000000000013ul); 210 res = syscall(SYS_socket, 2ul, 2ul, 0x88); 211 if (res != -1) 212 r[1] = res; 213 res = syscall(SYS_socketpair, 1ul, 1ul, 0, 0x20000000ul); 214 if (res != -1) 215 r[2] = *(uint32_t*)0x20000000; 216 res = syscall(SYS_dup2, r[2], r[1]); 217 if (res != -1) 218 r[3] = res; 219 memcpy((void*)0x20000140, "./file0\000", 8); 220 res = syscall(SYS_open, 0x20000140ul, 0ul, 0ul); 221 if (res != -1) 222 r[4] = res; 223 syscall(SYS_sendfile, r[4], r[3], 0ul, 1ul, 0ul, 0ul, 0ul); 224} 225int main(void) 226{ 227 syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); 228 for (procid = 0; procid < 4; procid++) { 229 if (fork() == 0) { 230 use_temporary_dir(); 231 loop(); 232 } 233 } 234 sleep(1000000); 235 return 0; 236} 237EOF 238mycc -o /tmp/syzkaller13 -Wall -Wextra -O2 /tmp/syzkaller13.c -lpthread || 239 exit 1 240 241(cd ../testcases/swap; ./swap -t 1m -i 20 -h > /dev/null 2>&1) & 242(cd /tmp; ./syzkaller13) & 243sleep 60 244while pkill swap; do sleep .1; done 245pkill -9 syzkaller13 246wait 247 248rm -f /tmp/syzkaller13 /tmp/syzkaller13.* /tmp/file0 249exit 0 250