syzbot


uvm_fault: killjobc

Status: fixed on 2018/12/18 19:33
Reported-by: syzbot+44bab40fc5a11357d774@syzkaller.appspotmail.com
Fix commit: When no child devices are attached to a wsmux device, make sure to return an
First crash: 2172d, last: 2172d

Sample crash report:
uvm_fault(0xffffff003f12c840, 0xd8, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      killjobc+0x39:  cmpq    %r13,0xd8(%r12)
ddb> 
ddb> set $lines = 0
ddb> show panic
kernel page fault
uvm_fault(0xffffff003f12c840, 0xd8, 0, 1) -> e
killjobc(ffff8000149d02f8) at killjobc+0x39 sys/kern/kern_proc.c:410
end trace frame: 0xffff800014ace9e0, count: 0
ddb> trace
killjobc(ffff8000149d02f8) at killjobc+0x39 sys/kern/kern_proc.c:410
exit1(ffff800014a33c30,9,0) at exit1+0x24b sys/kern/kern_exit.c:200
postsig(100,ffff800014a33c30) at postsig+0x3cc sigexit sys/kern/kern_sig.c:1500 [inline]
postsig(100,ffff800014a33c30) at postsig+0x3cc sys/kern/kern_sig.c:1432
userret(ffff800014acebd0) at userret+0xff sys/kern/kern_sig.c:1882
syscall(0) at syscall+0x45f mi_syscall_return sys/sys/syscall_mi.h:122 [inline]
syscall(0) at syscall+0x45f sys/arch/amd64/amd64/trap.c:605
Xsyscall(6,b,9,b,12e17d,8e89f970000) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7fffff4090, count: -6
ddb> show registers
rdi               0xffff8000149d02f8
rsi                            0x198
rbp               0xffff800014ace980
rbx               0xffffff0035f7de18
rdx                                0
rcx               0xffffff002d157110
rax                                0
r8                                 0
r9                                 0
r10                                0
r11               0xffffffff813e6600    pool_lock_mtx_leave
r12                                0
r13               0xffffff00376888c0
r14               0xffff8000149d02f8
r15               0xffffff002cfab1b0
rip               0xffffffff813ca7d9    killjobc+0x39
cs                               0x8
rflags                       0x10282    __ALIGN_SIZE+0xf282
rsp               0xffff800014ace960
ss                              0x10
killjobc+0x39:  cmpq    %r13,0xd8(%r12)
ddb> show proc
PROC (syz-executor0) pid=389689 stat=onproc
    flags process=a<EXEC,EXITING> proc=2000<WEXIT>
    pri=32, usrpri=50, nice=20
    forw=0xffffffffffffffff, list=0xffff800014a339d8,0xffff8000ffffcbd0
    process=0xffff8000149d02f8 user=0xffff800014ac9000, vmspace=0xffffff003f12c840
    estcpu=0, cpticks=0, pctcpu=0.0
    user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 72054   90422  47561      0  4     0x82010                syz-executor0
 72054  478036  47561      0  2   0x4082010                syz-executor0
 72054   57742  47561      0  3   0x4082010  inode         syz-executor0
 72054   55370  47561      0  3   0x4082010  inode         syz-executor0
 72054  195698  47561      0  3   0x4002010  suspend       syz-executor0
 73375    4565      1      0  3    0x100083  ttyin         getty
  9857  521346      0      0  3     0x14200  bored         sosplice
 42102  193871  68623      0  3        0x82  piperd        syz-executor1
 68623  190627  24196      0  3        0x82  thrsleep      syz-fuzzer
 68623  385594  24196      0  3   0x4000082  nanosleep     syz-fuzzer
 68623  302991  24196      0  3   0x4000082  thrsleep      syz-fuzzer
 68623  394775  24196      0  2   0x4000082                syz-fuzzer
 68623  427046  24196      0  2   0x4000002                syz-fuzzer
 68623   16683  24196      0  3   0x4000082  thrsleep      syz-fuzzer
 68623  208500  24196      0  3   0x4000082  thrsleep      syz-fuzzer
 24196   46828  59855      0  3    0x10008a  pause         ksh
 59855  171795  91914      0  3        0x92  select        sshd
 91914  330944      1      0  3        0x80  select        sshd
 14528  371606  50435     73  2    0x100010                syslogd
 50435   88159      1      0  3    0x100082  netio         syslogd
 53097   48074      1     77  3    0x100090  poll          dhclient
 60566  153483      1      0  3        0x80  poll          dhclient
 38416  505064      0      0  3     0x14200  pgzero        zerothread
 34178  209095      0      0  3     0x14200  aiodoned      aiodoned
 62317  102611      0      0  3     0x14200  syncer        update
 74567  436645      0      0  3     0x14200  cleaner       cleaner
 69828  403084      0      0  3     0x14200  reaper        reaper
 56801  352078      0      0  3     0x14200  pgdaemon      pagedaemon
 99456  123136      0      0  3     0x14200  bored         crynlk
 76353  241709      0      0  3     0x14200  bored         crypto
 59210  383566      0      0  3  0x40014200  acpi0         acpi0
 68431   11315      0      0  3     0x14200  bored         softnet
  1212  308051      0      0  3     0x14200  bored         systqmp
 41116   81364      0      0  3     0x14200  bored         systq
 86977  243047      0      0  3  0x40014200  bored         softclock
 25294  199213      0      0  3  0x40014200                idle0
     1  440949      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/12/14 11:46 openbsd b8bc906ae908 fe7127be .config console log report ci-openbsd-main
* Struck through repros no longer work on HEAD.