syzbot


assert "type != NULL" failed in subr_witness.c

Status: fixed on 2023/09/13 21:39
Reported-by: syzbot+ecc0e8628b3db39b5b17@syzkaller.appspotmail.com
Fix commit: ed07db5bc17e Revert commitid: yfAefyNWibUyjkU2, ESyyH5EKxtrXGkS6 and itscfpFvJLOj8mHB;
First crash: 446d, last: 446d

Sample crash report:
login: panic: kernel diagnostic assertion "type != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/subr_witness.c", line 1490
Stopped at      db_enter+0x1c:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
 463623  96885      0           0          0    0  syz-executor.3
db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff827a15bc) at panic+0x17b sys/kern/subr_prf.c:198
__assert(ffffffff8281ff28,ffffffff82801845,5d2,ffffffff82831a30) at __assert+0x29 sys/kern/subr_prf.c:157
enroll(0,0,ffffffff82bb90e0) at enroll+0x62e sys/kern/subr_witness.c:1500
witness_lock(fffffd806f00e0e8,8) at witness_lock+0xf2 sys/kern/subr_witness.c:1147
mtx_enter_try(fffffd806f00e0d8) at mtx_enter_try+0x104
mtx_enter(fffffd806f00e0d8) at mtx_enter+0x7f sys/kern/kern_lock.c:266
knote_remove(ffff80002124ba98,fffffd806f00e0d8,fffffd806f00e160,3,0) at knote_remove+0x20d sys/kern/kern_event.c:1881
knote_fdclose(ffff80002124ba98,3) at knote_fdclose+0xae sys/kern/kern_event.c:1934
fdfree(ffff80002124ba98) at fdfree+0xdf sys/kern/kern_descrip.c:1196
exit1(ffff80002124ba98,0,0,1) at exit1+0x3ff sys/kern/kern_exit.c:206
sys_exit(ffff80002124ba98,ffff8000213c9310,ffff8000213c9360) at sys_exit+0x1a sys/kern/kern_exit.c:89
syscall(ffff8000213c93e0) at syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline]
syscall(ffff8000213c93e0) at syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78acde1b8650, count: 1
https://www.openbsd.org/ddb.html describes the minimum info required in bug
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ddb{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: kernel diagnostic assertion "type != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/subr_witness.c", line 1490
ddb{1}> trace
db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff827a15bc) at panic+0x17b sys/kern/subr_prf.c:198
__assert(ffffffff8281ff28,ffffffff82801845,5d2,ffffffff82831a30) at __assert+0x29 sys/kern/subr_prf.c:157
enroll(0,0,ffffffff82bb90e0) at enroll+0x62e sys/kern/subr_witness.c:1500
witness_lock(fffffd806f00e0e8,8) at witness_lock+0xf2 sys/kern/subr_witness.c:1147
mtx_enter_try(fffffd806f00e0d8) at mtx_enter_try+0x104
mtx_enter(fffffd806f00e0d8) at mtx_enter+0x7f sys/kern/kern_lock.c:266
knote_remove(ffff80002124ba98,fffffd806f00e0d8,fffffd806f00e160,3,0) at knote_remove+0x20d sys/kern/kern_event.c:1881
knote_fdclose(ffff80002124ba98,3) at knote_fdclose+0xae sys/kern/kern_event.c:1934
fdfree(ffff80002124ba98) at fdfree+0xdf sys/kern/kern_descrip.c:1196
exit1(ffff80002124ba98,0,0,1) at exit1+0x3ff sys/kern/kern_exit.c:206
sys_exit(ffff80002124ba98,ffff8000213c9310,ffff8000213c9360) at sys_exit+0x1a sys/kern/kern_exit.c:89
syscall(ffff8000213c93e0) at syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline]
syscall(ffff8000213c93e0) at syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78acde1b8650, count: -14
ddb{1}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff8000213c8ea0
rbx               0xffff800020d59b9f
rdx                            0x3fd
rcx                                0
rax                             0x89
r8                 0x101010101010101
r9                0x8080808080808080
r10               0x263a091754090643
r11               0x459b24365493a29f
r12               0xffff800020d599a0
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff81508bec    db_enter+0x1c
cs                               0x8
rflags                         0x246
rsp               0xffff8000213c8e90
ss                              0x10
db_enter+0x1c:  addq    $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor.4) pid=171807 stat=onproc
    flags process=1008<EXITING,SINGLEEXIT> proc=2000<WEXIT>
    pri=0, usrpri=76, nice=20
    forw=0xffffffffffffffff, list=0xffff80002124a558,0xffff80002124bd50
    process=0xffff80002129e198 user=0xffff8000213c4000, vmspace=0xfffffd8069026020
    estcpu=36, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 96885  463623  25683      0  7           0                syz-executor.3
 96885  310313  25683      0  3   0x4000080  fsleep        syz-executor.3
 45306   61421   9617      0  2           0                syz-executor.2
 45306  167200   9617      0  3   0x4000080  fsleep        syz-executor.2
 78964  489986      0      0  3     0x14200  bored         sosplice
 25683  134399  87392      0  3        0x82  nanoslp       syz-executor.3
 87341  294942  87392      0  3         0x2  biowait       syz-executor.5
 72973  394151  87392      0  3        0x82  nanoslp       syz-executor.6
 61454  306003  87392      0  3        0x82  nanoslp       syz-executor.7
 66353  135044  87392      0  3        0x82  nanoslp       syz-executor.4
 91547   86701  87392      0  3        0x82  nanoslp       syz-executor.1
  9617  283079  87392      0  3        0x82  nanoslp       syz-executor.2
 95752  168390  87392      0  2         0x2                syz-executor.0
 87392  492799  88848      0  3   0x2000082  thrsleep      syz-execprog
 87392  324284  88848      0  3   0x6000082  thrsleep      syz-execprog
 87392  438071  88848      0  3   0x6000082  thrsleep      syz-execprog
 87392  378357  88848      0  3   0x6000082  thrsleep      syz-execprog
 87392  488443  88848      0  3   0x6000082  wait          syz-execprog
 87392  120751  88848      0  3   0x6000082  wait          syz-execprog
 87392  451243  88848      0  3   0x6000082  wait          syz-execprog
 87392  189978  88848      0  3   0x6000082  wait          syz-execprog
 87392  105904  88848      0  3   0x6000082  thrsleep      syz-execprog
 87392  153339  88848      0  3   0x6000082  wait          syz-execprog
 87392  176312  88848      0  3   0x6000082  thrsleep      syz-execprog
 87392  474952  88848      0  3   0x6000082  wait          syz-execprog
 87392   51999  88848      0  3   0x6000082  wait          syz-execprog
 87392  281194  88848      0  3   0x6000082  wait          syz-execprog
 87392  230556  88848      0  3   0x6000082  kqread        syz-execprog
 87392  416553  88848      0  3   0x6000082  thrsleep      syz-execprog
 88848   45817   7784      0  3    0x10008a  sigsusp       ksh
  7784  229200  27374      0  3        0x9a  kqread        sshd
 12869  376612      1      0  3    0x100083  ttyin         getty
 27374  251909      1      0  3        0x88  kqread        sshd
 66228  442428  34524     74  3   0x1100092  bpf           pflogd
 34524  145532      1      0  3        0x80  netio         pflogd
 94726  125851  81575     73  3   0x1100090  kqread        syslogd
 81575  328776      1      0  3    0x100082  netio         syslogd
 44435   32408      1      0  3    0x100080  kqread        resolvd
 83512  304621  17444     77  3    0x100092  kqread        dhcpleased
 37313  232668  17444     77  3    0x100092  kqread        dhcpleased
 17444  438408      1      0  3        0x80  kqread        dhcpleased
  1227  409576      0      0  3     0x14200  bored         smr
 56189  279341      0      0  2     0x14200                zerothread
  7010  145698      0      0  3     0x14200  aiodoned      aiodoned
 52481  159899      0      0  3     0x14200  syncer        update
 95403  369639      0      0  3     0x14200  cleaner       cleaner
 64156  392878      0      0  2     0x14200                reaper
 26616  296455      0      0  3     0x14200  pgdaemon      pagedaemon
 84713  109270      0      0  3     0x14200  bored         viomb
 58368  124683      0      0  3  0x40014200  acpi0         acpi0
 37225  447361      0      0  3  0x40014200                idle1
 60275  151407      0      0  3     0x14200  bored         softnet3
  2877  318098      0      0  3     0x14200  bored         softnet2
 64856  197702      0      0  3     0x14200  bored         softnet1
 44634  199789      0      0  3     0x14200  bored         softnet0
 83829  214648      0      0  3     0x14200  bored         systqmp
 84377  395280      0      0  3     0x14200  bored         systq
 73343  414381      0      0  3  0x40014200  bored         softclock
 38779  450926      0      0  3  0x40014200                idle0
     1  239516      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
Process 87341 (syz-executor.5) thread 0xffff800021224000 (294942)
exclusive rrwlock inode r = 0 (0xfffffd807b33e918)
#0  witness_lock+0x447
#1  rw_enter+0x3c8 sys/kern/kern_rwlock.c:309
#2  rrw_enter+0x8c sys/kern/kern_rwlock.c:464
#3  VOP_LOCK+0x8b sys/kern/vfs_vops.c:518
#4  vn_lock+0x84 sys/kern/vfs_vnops.c:564
#5  vget+0x200 sys/kern/vfs_subr.c:676
#6  ufs_ihashget+0x121 sys/ufs/ufs/ufs_ihash.c:119
#7  ffs_vget+0x7c sys/ufs/ffs/ffs_vfsops.c:1314
#8  ufs_lookup+0x13ba sys/ufs/ufs/ufs_lookup.c:487
#9  VOP_LOOKUP+0x5c sys/kern/vfs_vops.c:85
#10 vfs_lookup+0x6e2 sys/kern/vfs_lookup.c:566
#11 namei+0x55a sys/kern/vfs_lookup.c:250
#12 dounlinkat+0x9d sys/kern/vfs_syscalls.c:1847
#13 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline]
#13 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623
#14 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd80696e9b48)
#0  witness_lock+0x447
#1  rw_enter+0x3c8 sys/kern/kern_rwlock.c:309
#2  rrw_enter+0x8c sys/kern/kern_rwlock.c:464
#3  VOP_LOCK+0x8b sys/kern/vfs_vops.c:518
#4  vn_lock+0x84 sys/kern/vfs_vnops.c:564
#5  vfs_lookup+0xd5 sys/kern/vfs_lookup.c:418
#6  namei+0x55a sys/kern/vfs_lookup.c:250
#7  dounlinkat+0x9d sys/kern/vfs_syscalls.c:1847
#8  syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline]
#8  syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623
#9  Xsyscall+0x128
ddb{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 10187   6474K    6474K  78643K     11265        0
            pcb    13      8K       8K  78643K        13        0
         rtable   234      6K       6K  78643K       356        0
             pf    32      9K      10K  78643K        43        0
         ifaddr    45     15K      15K  78643K        47        0
        ifgroup    55      2K       2K  78643K        55        0
       counters    60     35K      35K  78643K        60        0
       ioctlops     0      0K       4K  78643K      1483        0
          mount     1      1K       1K  78643K         1        0
            log     0      0K       0K  78643K         4        0
         vnodes  1176     74K      74K  78643K      1192        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       1K  78643K         2        0
         VM map     2      1K       1K  78643K         2        0
            sem     2      0K       0K  78643K         2        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1697    195K     286K  78643K     12548        0
      file desc    13     45K      89K  78643K       414        0
           proc    67     91K     115K  78643K       526        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
       in_multi    99      7K       7K  78643K        99        0
    ether_multi     1      0K       0K  78643K         1        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys    25    122K     122K  78643K        25        0
           exec     0      0K       1K  78643K       393        0
            tdb     3      0K       0K  78643K         3        0
        pagedep     1      8K       8K  78643K         1        0
       inodedep     1     32K      32K  78643K         1        0
         newblk     1      0K       0K  78643K         1        0
        VM swap     8     62K      64K  78643K        10        0
       UVM amap   248     75K      75K  78643K      5860        0
       UVM aobj     3      2K       2K  78643K         3        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
            NDP    12      0K       2K  78643K        28        0
           temp     1   5904K    5968K  78643K      4834        0
         kqueue    13     20K      26K  78643K       307        0
      SYN cache     2     16K      16K  78643K         2        0
ddb{1}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache    128       22    0        0     1     0     1     1     0     8    0
rtpcb      120       37    0       34     1     0     1     1     0     8    0
rtentry    112      111    0        1     4     0     4     4     0     8    0
unpcb      144      317    0      300     1     0     1     1     0     8    0
syncache   304        5    0        5     1     1     0     1     0     8    0
tcpqe       32      136    0      136     1     1     0     1     0     8    0
tcpcb      808        8    0        5     1     0     1     1     0     8    0
arp        120       18    0        0     1     0     1     1     0     8    0
inpcb      368      348    0      339     2     0     2     2     0     8    1
nd6        136       24    0        0     1     0     1     1     0     8    0
pfosfp      40     1428    0     1005     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfstitem    24       20    0        0     1     0     1     1     0     8    0
pfstkey    128       20    0        0     1     0     1     1     0     8    0
pfstate    376       20    0        0     2     0     2     2     0     8    0
pfrule     1344      21    0       16     2     1     1     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      453    0        0    29     0    29    29     0     8    0
art_table   32      454    0        0     4     0     4     4     0     8    0
art_node    16      110    0       10     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1776    0      328    91     0    91    91     0     8    0
ffsino     272     1776    0      328    97     0    97    97     0     8    0
nchpl      144     2311    0      624    63     0    63    63     0     8    0
uvmvnodes   80     1790    0        0    37     0    37    37     0     8    0
vnodes     216     1790    0        0   100     0   100   100     0     8    0
namei      1024    7457    0     7457     2     0     2     2     0     8    2
percpumem   16       43    0        0     1     0     1     1     0     8    0
kstatmem   264       24    0        0     2     0     2     2     0     8    0
scxspl     216     8085    0     8084     3     2     1     2     1     8    0
plimitpl   152       35    0       19     1     0     1     1     0     8    0
sigapl     424      745    0      698     8     1     7     7     0     8    1
futexpl     64     1441    0     1439     1     0     1     1     0     8    0
knotepl    120      114    0        0     4     0     4     4     0     8    0
kqueuepl   216      303    0      294     1     0     1     1     0     8    0
pipepl     320      147    0      119     3     0     3     3     0     8    0
fdescpl    496      727    0      701     5     0     5     5     0     8    0
filepl     152     2568    0     2430     6     0     6     6     0     8    0
lockfpl    104        6    0        4     1     0     1     1     0     8    0
lockfspl    48        4    0        2     1     0     1     1     0     8    0
sessionpl  144       26    0        9     1     0     1     1     0     8    0
pgrppl      48       26    0        9     1     0     1     1     0     8    0
ucredpl    104       71    0       59     1     0     1     1     0     8    0
zombiepl   144      702    0      698     1     0     1     1     0     8    0
processpl  1072     745    0      698     4     0     4     4     0     8    0
procpl     680     1043    0      978     7     1     6     6     0     8    0
sosppl     168      282    0      277     1     0     1     1     0     8    0
sockpl     488      702    0      670     5     0     5     5     0     8    1
mcl8k      8192       2    0        0     1     0     1     1     0     8    0
mcl4k      4096       2    0        0     1     0     1     1     0     8    0
mcl2k      2048     272    0        0    34     0    34    34     0     8    0
mtagpl      96        2    0        0     1     0     1     1     0     8    0
mbufpl     256      284    0        0    18     0    18    18     0     8    0
bufpl      288     4448    0      138   308     0   308   308     0     8    0
anonpl      24   216235    0   211664    60     2    58    59     0   186   28
amapchunkpl 152   19093    0    18502    28     0    28    28     0   158    3
amappl16   200     5874    0     5804     5     0     5     5     0     8    0
amappl15   192       35    0       35     1     1     0     1     0     8    0
amappl14   184      191    0      178     2     0     2     2     0     8    1
amappl13   176       11    0       10     1     0     1     1     0     8    0
amappl12   168     1426    0     1398     3     1     2     2     0     8    0
amappl11   160       68    0       53     1     0     1     1     0     8    0
amappl10   152       43    0       33     1     0     1     1     0     8    0
amappl9    144      207    0      207     1     0     1     1     0     8    1
amappl8    136      148    0      119     2     0     2     2     0     8    0
amappl7    128       72    0       62     2     0     2     2     0     8    0
amappl6    120      238    0      219     2     0     2     2     0     8    1
amappl5    112      175    0      164     1     0     1     1     0     8    0
amappl4    104      638    0      591     3     0     3     3     0     8    1
amappl3     96     4180    0     4108     4     1     3     3     0     8    0
amappl2     88      979    0      914     3     0     3     3     0     8    1
amappl1     80    12012    0    11467    23     2    21    23     0     8    8
amappl      88     5339    0     5173     5     0     5     5     0    92    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       1    0        0     1     0     1     1     0     8    0
dma256     256        6    0        6     1     1     0     1     0     8    0
dma128     128      253    0      253     1     1     0     1     0     8    0
dma64       64        6    0        6     1     1     0     1     0     8    0
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72        2    0        0     1     0     1     1     0     8    0
uaddrrnd    24      727    0      701     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      727    0      701     1     0     1     1     0     8    0
vmmpekpl   168    11546    0    11513     2     0     2     2     0     8    0
vmmpepl    168    61153    0    59487   117     0   117   117     0   357   39
vmsppl     464      726    0      701     5     0     5     5     0     8    1
rwobjpl     56    25283    0    22455    48     1    47    47     0     8    6
pdppl      4096    1462    0     1402   100    30    70    82     0     8   10
pvpl        32   465210    0   455421   356    10   346   355     0   265  259
pmappl     248      726    0      701     3     0     3     3     0     8    0
extentpl    40       56    0       38     1     0     1     1     0     8    0
phpool     112      698    0       33    20     0    20    20     0     8    0
ddb{1}> machine ddbcpu 0
Stopped at      x86_ipi_db+0x1e:        addq    $0x8,%rsp
x86_ipi_db(ffffffff82bf2ff0) at x86_ipi_db+0x1e sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 sys/kern/kern_lock.c:147
intr_handler(ffff8000213bd900,ffff80000006bc00) at intr_handler+0x62 sys/arch/amd64/amd64/intr.c:532
Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 sys/kern/kern_lock.c:147
syscall(ffff8000213bdad0) at syscall+0x5cd mi_syscall sys/sys/syscall_mi.h:110 [inline]
syscall(ffff8000213bdad0) at syscall+0x5cd sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x6fb0d1fffbd0, count: 6
ddb{0}> trace
x86_ipi_db(ffffffff82bf2ff0) at x86_ipi_db+0x1e sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 sys/kern/kern_lock.c:147
intr_handler(ffff8000213bd900,ffff80000006bc00) at intr_handler+0x62 sys/arch/amd64/amd64/intr.c:532
Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82d01718) at __mp_lock+0x122 sys/kern/kern_lock.c:147
syscall(ffff8000213bdad0) at syscall+0x5cd mi_syscall sys/sys/syscall_mi.h:110 [inline]
syscall(ffff8000213bdad0) at syscall+0x5cd sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x6fb0d1fffbd0, count: -9
ddb{0}> machine ddbcpu 1
Stopped at      db_enter+0x1c:  addq    $0x8,%rsp
db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff827a15bc) at panic+0x17b sys/kern/subr_prf.c:198
__assert(ffffffff8281ff28,ffffffff82801845,5d2,ffffffff82831a30) at __assert+0x29 sys/kern/subr_prf.c:157
enroll(0,0,ffffffff82bb90e0) at enroll+0x62e sys/kern/subr_witness.c:1500
witness_lock(fffffd806f00e0e8,8) at witness_lock+0xf2 sys/kern/subr_witness.c:1147
mtx_enter_try(fffffd806f00e0d8) at mtx_enter_try+0x104
mtx_enter(fffffd806f00e0d8) at mtx_enter+0x7f sys/kern/kern_lock.c:266
knote_remove(ffff80002124ba98,fffffd806f00e0d8,fffffd806f00e160,3,0) at knote_remove+0x20d sys/kern/kern_event.c:1881
knote_fdclose(ffff80002124ba98,3) at knote_fdclose+0xae sys/kern/kern_event.c:1934
fdfree(ffff80002124ba98) at fdfree+0xdf sys/kern/kern_descrip.c:1196
exit1(ffff80002124ba98,0,0,1) at exit1+0x3ff sys/kern/kern_exit.c:206
sys_exit(ffff80002124ba98,ffff8000213c9310,ffff8000213c9360) at sys_exit+0x1a sys/kern/kern_exit.c:89
syscall(ffff8000213c93e0) at syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline]
syscall(ffff8000213c93e0) at syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78acde1b8650, count: 1
ddb{1}> 

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/09/04 23:27 openbsd e36cf0cab4c6 0b6286dc .config console log report syz ci-openbsd-multicore assert "type != NULL" failed in subr_witness.c
* Struck through repros no longer work on HEAD.