syzbot


panic: vput: v_writecount != 0

Status: closed as invalid on 2019/07/22 06:58
Reported-by: syzbot+2a29c4391377f57ac593@syzkaller.appspotmail.com
First crash: 1953d, last: 1953d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd panic: vput: v_writecount != 0 (2) C 112 1938d 1943d 3/3 fixed on 2019/08/05 23:05

Sample crash report:
panic: vput: v_writecount != 0
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:212
vput(fffffd803c54b968) at vput+0x187 sys/kern/vfs_subr.c:759
vn_closefile(fffffd8036164620,ffff8000ffff4778) at vn_closefile+0x15b sys/kern/vfs_vnops.c:589
fdrop(fffffd8036164620,ffff8000ffff4778) at fdrop+0xc9 sys/kern/kern_descrip.c:1269
closef(fffffd8036164620,ffff8000ffff4778) at closef+0x118 sys/kern/kern_descrip.c:1253
fdfree(ffff8000ffff4778) at fdfree+0xf7 sys/kern/kern_descrip.c:1185
exit1(ffff8000ffff4778,0,1) at exit1+0x32f sys/kern/kern_exit.c:196
sys_exit(ffff8000ffff4778,ffff80001497ad70,ffff80001497ade0) at sys_exit+0x17 sys/kern/kern_exit.c:94
syscall(ffff80001497ae40) at syscall+0x508
Xsyscall(6,1,9c38304f000,1,7f7ffffcf5b8,0) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffcf530, count: 4
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.
ddb> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
vput: v_writecount != 0
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:212
vput(fffffd803c54b968) at vput+0x187 sys/kern/vfs_subr.c:759
vn_closefile(fffffd8036164620,ffff8000ffff4778) at vn_closefile+0x15b sys/kern/vfs_vnops.c:589
fdrop(fffffd8036164620,ffff8000ffff4778) at fdrop+0xc9 sys/kern/kern_descrip.c:1269
closef(fffffd8036164620,ffff8000ffff4778) at closef+0x118 sys/kern/kern_descrip.c:1253
fdfree(ffff8000ffff4778) at fdfree+0xf7 sys/kern/kern_descrip.c:1185
exit1(ffff8000ffff4778,0,1) at exit1+0x32f sys/kern/kern_exit.c:196
sys_exit(ffff8000ffff4778,ffff80001497ad70,ffff80001497ade0) at sys_exit+0x17 sys/kern/kern_exit.c:94
syscall(ffff80001497ae40) at syscall+0x508
Xsyscall(6,1,9c38304f000,1,7f7ffffcf5b8,0) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffcf530, count: -11
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80001497aa60
rbx               0xffff80001497ab10
rdx                              0x2
rcx                              0x1
rax                              0x1
r8                0xffff80001497aa20
r9                               0x1
r10               0x664fd4b721e44895
r11               0xf56480a474f879e4
r12                     0x3000000008
r13               0xffff80001497aa70
r14                            0x100
r15                              0x1
rip               0xffffffff8125b5f8    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff80001497aa50
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor7698) pid=26392 stat=onproc
    flags process=100a<EXEC,EXITING,SINGLEEXIT> proc=2000<WEXIT>
    pri=32, usrpri=51, nice=20
    forw=0xffffffffffffffff, list=0xffff8000ffff5158,0xffffffff822c3340
    process=0xffff800014942018 user=0xffff800014975000, vmspace=0xfffffd803f014110
    estcpu=1, cpticks=2, pctcpu=0.17
    user=0, sys=2, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 73377  257695  64921      0  3    0x10008a  pause         ksh
 64921  447245  93482      0  3        0x92  select        sshd
 49959  197825      1      0  3    0x100083  ttyin         getty
 93482   71649      1      0  3        0x80  select        sshd
 64105  281332  79172     73  2    0x100090                syslogd
 79172  151659      1      0  3    0x100082  netio         syslogd
 76126  399401      1     77  3    0x100090  poll          dhclient
  1099   97417      1      0  3        0x80  poll          dhclient
 58472     449      0      0  2     0x14200                zerothread
 37070   99317      0      0  3     0x14200  aiodoned      aiodoned
 59478   72147      0      0  3     0x14200  syncer        update
 23860  494830      0      0  3     0x14200  cleaner       cleaner
 87394   42790      0      0  3     0x14200  reaper        reaper
 78351  261454      0      0  3     0x14200  pgdaemon      pagedaemon
 62103  412180      0      0  3     0x14200  bored         crynlk
 82040  126227      0      0  3     0x14200  bored         crypto
 49473  301178      0      0  3  0x40014200  acpi0         acpi0
 18939  518880      0      0  3     0x14200  bored         softnet
  1055   49461      0      0  3     0x14200  bored         systqmp
 86508  155873      0      0  3     0x14200  bored         systq
 37191  156076      0      0  2  0x40014200                softclock
 54492  451475      0      0  3  0x40014200                idle0
 30700  267962      0      0  3     0x14200  bored         smr
     1  385230      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim Kern Lim
         devbuf  9428   6307K    6309K  78643K     10523        0        0
            pcb    13      8K       8K  78643K        13        0        0
         rtable    61      1K       2K  78643K       115        0        0
         ifaddr    21      7K       7K  78643K        21        0        0
       counters    19     16K      16K  78643K        19        0        0
       ioctlops     0      0K       2K  78643K        13        0        0
          mount     1      1K       1K  78643K         1        0        0
         vnodes  1181     74K      74K  78643K      1186        0        0
      UFS quota     1     32K      32K  78643K         1        0        0
      UFS mount     5     36K      36K  78643K         5        0        0
            shm     2      1K       1K  78643K         2        0        0
         VM map     2      0K       0K  78643K         2        0        0
            sem     2      0K       0K  78643K         2        0        0
        dirhash    12      2K       2K  78643K        12        0        0
           ACPI  1793    195K     288K  78643K     12645        0        0
      file desc     1      0K       0K  78643K         1        0        0
           proc    40     30K      38K  78643K       257        0        0
    NFS srvsock     1      0K       0K  78643K         1        0        0
     NFS daemon     1     16K      16K  78643K         1        0        0
       in_multi    11      0K       0K  78643K        11        0        0
    ether_multi     1      0K       0K  78643K         1        0        0
    ISOFS mount     1     32K      32K  78643K         1        0        0
  MSDOSFS mount     1     16K      16K  78643K         1        0        0
           ttys    18     79K      79K  78643K        18        0        0
           exec     0      0K       1K  78643K       152        0        0
        pagedep     1      8K       8K  78643K         1        0        0
       inodedep     1     32K      32K  78643K         1        0        0
         newblk     1      0K       0K  78643K         1        0        0
        VM swap     7     26K      26K  78643K         7        0        0
       UVM amap    61      3K       3K  78643K       709        0        0
       UVM aobj     2      2K       2K  78643K         2        0        0
        memdesc     1      4K       4K  78643K         1        0        0
    crypto data     1      1K       1K  78643K         1        0        0
            NDP     3      0K       0K  78643K         3        0        0
           temp    30   2707K    2771K  78643K      1715        0        0
      SYN cache     2     16K      16K  78643K         2        0        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64        2    0        0     1     0     1     1     0     8    0
rtpcb       80       15    0       13     1     0     1     1     0     8    0
rtentry    112       23    0        1     1     0     1     1     0     8    0
unpcb      120       27    0       19     1     0     1     1     0     8    0
syncache   264        5    0        5     1     0     1     1     0     8    1
tcpcb      544        8    0        5     1     0     1     1     0     8    0
inpcb      280       22    0       16     1     0     1     1     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256       96    0        0     6     0     6     6     0     8    0
art_table   32       97    0        0     1     0     1     1     0     8    0
art_node    16       22    0        2     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     1393    0       17    45     0    45    45     0     8    0
ffsino     240     1393    0       17    81     0    81    81     0     8    0
nchpl      144     1578    0       43    57     0    57    57     0     8    0
uvmvnodes   72     1402    0        0    26     0    26    26     0     8    0
vnodes     200     1402    0        0    74     0    74    74     0     8    0
namei      1024    3371    0     3371     2     1     1     1     0     8    1
scxspl     192    18766    0    18766     8     7     1     6     0     8    1
plimitpl   152       13    0        8     1     0     1     1     0     8    0
sigapl     432      176    0      166     2     0     2     2     0     8    0
futexpl     56        7    0        7     1     0     1     1     0     8    1
knotepl    112        5    0        0     1     0     1     1     0     8    0
kqueuepl   104        1    0        0     1     0     1     1     0     8    0
pipepl     112      118    0      111     2     1     1     1     0     8    0
fdescpl    424      177    0      166     2     0     2     2     0     8    0
filepl     120      842    0      798     2     0     2     2     0     8    0
lockfpl    104        6    0        6     1     1     0     1     0     8    0
lockfspl    48        3    0        3     1     1     0     1     0     8    0
sessionpl  112       17    0        9     1     0     1     1     0     8    0
pgrppl      48       17    0        9     1     0     1     1     0     8    0
ucredpl     96       47    0       40     1     0     1     1     0     8    0
zombiepl   144      167    0      166     2     1     1     1     0     8    0
processpl  864      191    0      166     4     0     4     4     0     8    0
procpl     632      197    0      172     3     0     3     3     0     8    0
sockpl     384       64    0       48     2     0     2     2     0     8    0
mcl4k      4096      10    0       10     1     0     1     1     0     8    1
mcl2k      2048    6105    0     6070     8     2     6     8     0     8    1
mtagpl      80        2    0        2     1     1     0     1     0     8    0
mbufpl     256    10426    0    10380     7     3     4     6     0     8    0
bufpl      256    10270    0     5372   624     0   624   624     0     8  315
anonpl      16    22051    0    16769    24     2    22    22     0    62    0
amapchunkpl 152     503    0      441     3     0     3     3     0   158    0
amappl16   192      320    0       73    13     0    13    13     0     8    0
amappl14   176       36    0       32     1     0     1     1     0     8    0
amappl12   160        4    0        4     1     1     0     1     0     8    0
amappl11   152       40    0       29     1     0     1     1     0     8    0
amappl10   144       45    0       45     2     1     1     1     0     8    1
amappl9    136      389    0      388     1     0     1     1     0     8    0
amappl8    128       84    0       79     1     0     1     1     0     8    0
amappl7    120       15    0       14     1     0     1     1     0     8    0
amappl6    112       41    0       37     1     0     1     1     0     8    0
amappl5    104      138    0      129     1     0     1     1     0     8    0
amappl4     96      399    0      378     1     0     1     1     0     8    0
amappl3     88      147    0      136     1     0     1     1     0     8    0
amappl2     80      694    0      638     3     1     2     2     0     8    0
amappl1     72    12164    0    11763    16     6    10    16     0     8    0
amappl      80      371    0      345     1     0     1     1     0    84    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma256     256        6    0        6     1     1     0     1     0     8    0
dma64       64      259    0      259     1     1     0     1     0     8    0
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       17    0       17     1     1     0     1     0     8    0
aobjpl      64        1    0        0     1     0     1     1     0     8    0
uaddrrnd    24      177    0      166     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      177    0      166     1     0     1     1     0     8    0
vmmpekpl   168     5342    0     5327     1     0     1     1     0     8    0
vmmpepl    168    26052    0    25007    64    18    46    48     0   357    0
vmsppl     272      176    0      166     1     0     1     1     0     8    0
pdppl      4096     360    0      332     5     0     5     5     0     8    0
pvpl        32    75499    0    68609    61     5    56    56     0   265    0
pmappl     200      176    0      166     1     0     1     1     0     8    0
extentpl    40       41    0       26     1     0     1     1     0     8    0
phpool     112      742    0        8    21     0    21    21     0     8    0
ddb> 

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/07/21 02:53 openbsd 463b33d19ef0 1656845f .config console log report syz C ci-openbsd-main
2019/07/21 02:21 openbsd 463b33d19ef0 1656845f .config console log report ci-openbsd-main
* Struck through repros no longer work on HEAD.