syzbot


assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c (2)

Status: upstream: reported on 2026/03/14 05:45
Reported-by: syzbot+d5e80fc0033fb8f1e038@syzkaller.appspotmail.com
First crash: 91d, last: 12d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c -1 2 307d 309d 0/3 auto-obsoleted due to no activity on 2025/11/07 19:36

Sample crash report:
panic: kernel diagnostic assertion "atomic_load_int(&fdp->fd_nuserevents) == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_descrip.c", line 1219
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
 277485  36269  32767        0x10  0x4000000    1  syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834bb2e9) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff834f838c,ffffffff834d1f7b,4c3,ffffffff8348c944) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff8000fffe7ca8) at fdfree+0x349
exit1(ffff8000fffe7ca8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff8000fffe7ca8,ffff800036faca20,ffff800036fac970) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff800036faca20) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036faca20) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78997e0d9070, count: 7
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{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: kernel diagnostic assertion "atomic_load_int(&fdp->fd_nuserevents) == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_descrip.c", line 1219
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834bb2e9) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff834f838c,ffffffff834d1f7b,4c3,ffffffff8348c944) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff8000fffe7ca8) at fdfree+0x349
exit1(ffff8000fffe7ca8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff8000fffe7ca8,ffff800036faca20,ffff800036fac970) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff800036faca20) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036faca20) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78997e0d9070, count: -8
ddb{0}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff800036fac760
rbx               0xffffffff838f5e07    cpu_info_full_primary+0x2e07
rdx                                0
rcx               0xffff8000fffe7ca8
rax               0xffffffff838f4ff0    cpu_info_full_primary+0x1ff0
r8                 0x101010101010101
r9                0x8080808080808080
r10                0x796eebb8de43ad0
r11               0x924788f12577242d
r12               0xffffffff838f5c08    cpu_info_full_primary+0x2c08
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff81abcb95    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff800036fac750
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor) tid=204966 pid=34731 tcnt=0 stat=onproc
    flags process=1018<EXITING,SUGID,SINGLEEXIT> proc=2000<WEXIT>
    runpri=32, usrpri=53, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0xffff8000fffe7ca8 scnt=-1 ecnt=1
    forw=0xffffffffffffffff, list=0xffff8000fffe6a80,0xffff8000fffef4e8
    process=0xffff80003c3ce1d0 user=0xffff800036fa7000, vmspace=0xfffffd806c6a3ba0
    estcpu=3, cpticks=5, pctcpu=0.2, user=0, sys=2, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 65593  120942  51643  32767  2        0x10                syz-executor
 65593  415417  51643  32767  3   0x4000090  fsleep        syz-executor
 31648  156219  12004      0  2    0x100002                sh
  2918   15523  76025  32767  2        0x10                syz-executor
  2918   61820  76025  32767  3   0x4000090  fsleep        syz-executor
 31521  293140  32235  32767  2        0x10                syz-executor
 31521  162551  32235  32767  2   0x4000010                syz-executor
 68249  224511  72391  32767  2        0x10                syz-executor
 68249  415462  72391  32767  3   0x4000090  fsleep        syz-executor
 68249    5601  72391  32767  3   0x4000090  fsleep        syz-executor
 36269  195464  21403  32767  2       0xc90                syz-executor
 36269  277485  21403  32767  7   0x4000010                syz-executor
 36269   66892  21403  32767  3   0x4000090  fsleep        syz-executor
 32235  206802  76322  32767  2       0xc90                syz-executor
 51643  185422  29259  32767  2       0xc90                syz-executor
 72391   20265  41073  32767  2       0xc90                syz-executor
 76025  189772  39913  32767  2       0xc90                syz-executor
 12004  396206     76      0  3        0x80  wait          syz-executor
 16572   12734  60952  32767  2        0x10                syz-executor
 21403  475181  31721  32767  2       0xc90                syz-executor
 35111  361672  36975  32767  2       0xc90                syz-executor
 39913   49883  93177      0  3        0x82  wait          syz-executor
 41073  231342  93177      0  3        0x82  wait          syz-executor
    76  343549  93177      0  3        0x82  wait          syz-executor
 60952   33509  93177      0  3        0x82  wait          syz-executor
 31721  464025  93177      0  3        0x82  wait          syz-executor
 29259  214486  93177      0  3        0x82  wait          syz-executor
 76322  279055  93177      0  3        0x82  wait          syz-executor
 36975  116350  93177      0  3        0x82  wait          syz-executor
 93177  136218  89995      0  3        0x82  kqread        syz-executor
 89995   52716  17680      0  3    0x10008a  sigsusp       ksh
 17680   83981  74916      0  3        0x98  kqread        sshd-session
 74916  439301  14499      0  3        0x92  kqread        sshd-session
 25784  341778      1      0  3    0x100083  ttyin         getty
 14499  245806      1      0  3        0x88  kqread        sshd
 39802  125578   4926     73  3   0x1100090  kqread        syslogd
  4926  331214      1      0  3    0x100082  sbwait        syslogd
  8064  411416      1      0  3    0x100080  kqread        resolvd
 29263  489434  73020     77  3    0x100092  kqread        dhcpleased
 11206   58424  73020     77  3    0x100092  kqread        dhcpleased
 73020  352826      1      0  3        0x80  kqread        dhcpleased
 17032  332339      0      0  3     0x14200  bored         smr
 44914  399880      0      0  2     0x14200                zerothread
 94511  131267      0      0  3     0x14200  aiodoned      aiodoned
  8569  425151      0      0  3     0x14200  syncer        update
 60246  262467      0      0  3     0x14200  cleaner       cleaner
 33525  131118      0      0  2     0x14200                reaper
 10966  144731      0      0  3     0x14200  pgdaemon      pagedaemon
 73034  412055      0      0  3     0x14200  bored         viomb
 64213  369858      0      0  3  0x40014200  acpi0         acpi0
 30046  272263      0      0  3  0x40014200                idle1
  4254  497265      0      0  3     0x14200  bored         softnet1
 25267  219426      0      0  2     0x14200                softnet0
  2790  461001      0      0  3     0x14200  smrbar        systqmp
 79732  255570      0      0  3     0x14200  bored         systq
 15155  164009      0      0  3     0x14200  tmoslp        softclockmp
 10505  492207      0      0  3  0x40014200  tmoslp        softclock
 53105  353379      0      0  3  0x40014200                idle0
     1   71032      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
Process 16572 (syz-executor) thread 0xffff8000fffeed10 (12734)
exclusive rrwlock inode r = 0 (0xfffffd806c6ed1e8)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2  rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3  VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4  vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5  vget+0x2a2 sys/kern/vfs_subr.c:686
#6  ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98
#7  ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1203
#8  ufs_lookup+0x1a36 sys/ufs/ufs/ufs_lookup.c:478
#9  VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
#10 vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
#11 namei+0x7c5 sys/kern/vfs_lookup.c:250
#12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1893
#13 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#13 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#14 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd806cdd0300)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2  rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3  VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4  vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5  vfs_lookup+0x12b sys/kern/vfs_lookup.c:431
#6  namei+0x7c5 sys/kern/vfs_lookup.c:250
#7  dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1893
#8  syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8  syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#9  Xsyscall+0x128
Process 2790 (systqmp) thread 0xffff8000ffffecf8 (461001)
shared rwlock systqmp r = 0 (0xffffffff838d0d48)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  taskq_thread+0x12a sys/kern/kern_task.c:442
#2  proc_trampoline+0x10
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11051  12018K   12034K 166960K     12142        0
            pcb    17     12K      12K 166960K        17        0
         rtable   239      6K       7K 166960K       349        0
             pf    31     16K      16K 166960K        31        0
         ifaddr    42      7K       7K 166960K        44        0
        ifgroup    50      2K       2K 166960K        50        0
         sysctl     1      1K       9K 166960K         5        0
       counters    70     37K      37K 166960K        70        0
       ioctlops     0      0K       2K 166960K        30        0
            iov     0      0K       8K 166960K         6        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1287     81K      81K 166960K      1355        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K         3        0
         VM map     2      1K       1K 166960K         2        0
            sem     5      0K       0K 166960K         5        0
        dirhash    12      2K       2K 166960K        12        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    24     89K     125K 166960K       178        0
          sigio     0      0K       0K 166960K         2        0
           proc    58     99K     163K 166960K       506        0
        subproc    72      4K       4K 166960K        72        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     4      0K       0K 166960K        13        0
       in_multi   100      7K       7K 166960K       100        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K         1        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    49    228K     228K 166960K        49        0
           exec     0      0K       1K 166960K       364        0
   fusefs mount     1     32K      32K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   246    169K     175K 166960K      3186        0
       UVM aobj     4      2K       2K 166960K         4        0
     pinsyscall    46     92K     110K 166960K      1245        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     1      0K       0K 166960K         2        0
            NDP    27      2K       2K 166960K        27        0
           temp    37   9111K    9116K 166960K      3717        0
         kqueue    15     20K      23K 166960K        39        0
      SYN cache     2     16K      16K 166960K         2        0
ddb{0}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache    128       26    0        0     1     0     1     1     0     8    0
rtpcb      120       39    0       36     1     0     1     1     0     8    0
rtentry    176      112    0        1     6     0     6     6     0     8    0
unpcb      144       57    0       42     1     0     1     1     0     8    0
syncache   336        4    0        4     1     0     1     1     0     8    1
sackhl      24        1    0        1     1     0     1     1     0     8    1
tcpcb      736       21    0       15     1     0     1     1     0     8    0
arp        136       18    0        0     1     0     1     1     0     8    0
inpcb      328      105    0       94     2     0     2     2     0     8    0
nd6        152       25    0        0     1     0     1     1     0     8    0
kcovpl      48        8    0        0     1     0     1     1     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      469    0        0    30     0    30    30     0     8    0
art_table   40      470    0        0     5     0     5     5     0     8    0
art_node    32      112    0       10     1     0     1     1     0     8    0
sysvmsgpl   40        1    0        0     1     0     1     1     0     8    0
semupl     112        1    0        0     1     0     1     1     0     8    0
semapl      72        3    0        0     1     0     1     1     0     8    0
shmpl      112        1    0        0     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1601    0      136    92     0    92    92     0     8    0
ffsino     296     1601    0      136   113     0   113   113     0     8    0
nchpl      144     1847    0      153    63     0    63    63     0     8    0
vnodes     216     1682    0        0    94     0    94    94     0     8    0
namei      1024    5394    0     5394     1     0     1     1     0     8    1
percpumem   16       50    0        0     1     0     1     1     0     8    0
kstatmem   264       25    0        0     2     0     2     2     0     8    0
scxspl     216     6485    0     6485     6     2     4     4     1     8    4
plimitpl   152       46    0       21     2     0     2     2     0     8    1
sigapl     424      467    0      414     7     0     7     7     0     8    0
knotepl    120      109    0        0     4     0     4     4     0     8    0
kqueuepl   224       29    0       19     1     0     1     1     0     8    0
pipepl     344      126    0       99     3     0     3     3     0     8    0
fdescpl    528      451    0      414     4     0     4     4     0     8    0
filepl     160     1631    0     1418    11     0    11    11     0     8    1
lockfpl    104        8    0        6     1     0     1     1     0     8    0
lockfspl    48        5    0        3     1     0     1     1     0     8    0
sessionpl  144       27    0       11     1     0     1     1     0     8    0
pgrppl      48       35    0       11     1     0     1     1     0     8    0
ucredpl    104      149    0      131     1     0     1     1     0     8    0
zombiepl   144      415    0      414     1     0     1     1     0     8    0
processpl  1232     467    0      414     5     0     5     5     0     8    0
procpl     664      527    0      466     6     0     6     6     0     8    0
sockpl     752      201    0      172     5     0     5     5     0     8    1
mcl64k     65536      1    0        0     1     0     1     1     0     8    0
mcl16k     16384      1    0        0     1     0     1     1     0     8    0
mcl8k      8192       2    0        0     1     0     1     1     0     8    0
mcl4k      4096     125    0        0    16     0    16    16     0     8    0
mcl2k      2048      15    0        0     2     0     2     2     0     8    0
mtagpl      96        2    0        0     1     0     1     1     0     8    0
mbufpl     256      175    0        0    11     0    11    11     0     8    0
bufpl      280     2265    0      102   155     0   155   155     0     8    0
anonpl      32     3497    0        0    29     0    29    29     0   246    0
amapchunkpl 152    8808    0     8268    23     0    23    23     0   158    0
amappl16   200     1485    0     1467     5     0     5     5     0     8    3
amappl15   192       31    0       31     1     0     1     1     0     8    1
amappl14   184      412    0      410     1     0     1     1     0     8    0
amappl13   176      114    0      104     1     0     1     1     0     8    0
amappl12   168      678    0      643     2     0     2     2     0     8    0
amappl11   160        2    0        2     1     0     1     1     0     8    1
amappl10   152       66    0       56     1     0     1     1     0     8    0
amappl9    144      271    0      271     1     0     1     1     0     8    1
amappl8    136       92    0       91     1     0     1     1     0     8    0
amappl7    128      141    0      129     1     0     1     1     0     8    0
amappl6    120      151    0      148     1     0     1     1     0     8    0
amappl5    112      104    0       97     1     0     1     1     0     8    0
amappl4    104      257    0      241     1     0     1     1     0     8    0
amappl3     96     1573    0     1445     5     1     4     4     0     8    0
amappl2     88      501    0      448     2     0     2     2     0     8    0
amappl1     80    10173    0     9597    14     0    14    14     0     8    0
amappl      88     2519    0     2339     5     0     5     5     0    92    0
uvmvnodes   80       99    0        0     3     0     3     3     0     8    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        3    0        0     1     0     1     1     0     8    0
uaddrrnd    24      451    0      414     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      451    0      414     1     0     1     1     0     8    0
vmmpekpl   168     5493    0     5460     2     0     2     2     0     8    0
vmmpepl    168    37569    0    35550    93     0    93    93     0   357    1
vmsppl     488      450    0      414     7     1     6     6     0     8    0
rwobjpl     80    13975    0    13020    22     0    22    22     0     8    0
pdppl      4096     909    0      828   107    10    97    97     0     8   16
pvpl        32    10251    0        0    83     0    83    83     0   265    0
pmappl     256      450    0      414     4     1     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      275    0       13     8     0     8     8     0     8    0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834bb2e9) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff834f838c,ffffffff834d1f7b,4c3,ffffffff8348c944) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff8000fffe7ca8) at fdfree+0x349
exit1(ffff8000fffe7ca8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff8000fffe7ca8,ffff800036faca20,ffff800036fac970) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff800036faca20) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036faca20) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78997e0d9070, count: -8
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
x86_ipi_db(ffff80002999dff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 kd_curproc sys/dev/kcov.c:585 [inline]
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 sys/dev/kcov.c:153
__mp_lock(ffffffff83ab9680) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83ab9680) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173
sysctl_file(ffff80003c3d5978,4,200000000100,ffff80003c3d59a8,ffff8000fffeea78) at sysctl_file+0x2d20 sys/kern/kern_sysctl.c:1796
kern_sysctl(ffff80003c3d5974,5,200000000100,ffff80003c3d59a8,0,37,7312dc20c7762fd0) at kern_sysctl+0x139 sys/kern/kern_sysctl.c:736
sys_sysctl(ffff8000fffeea78,ffff80003c3d5ae0,ffff80003c3d5a30) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80003c3d5ae0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3d5ae0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x4959a16c030, count: 5
ddb{1}> trace
x86_ipi_db(ffff80002999dff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 kd_curproc sys/dev/kcov.c:585 [inline]
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 sys/dev/kcov.c:153
__mp_lock(ffffffff83ab9680) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83ab9680) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173
sysctl_file(ffff80003c3d5978,4,200000000100,ffff80003c3d59a8,ffff8000fffeea78) at sysctl_file+0x2d20 sys/kern/kern_sysctl.c:1796
kern_sysctl(ffff80003c3d5974,5,200000000100,ffff80003c3d59a8,0,37,7312dc20c7762fd0) at kern_sysctl+0x139 sys/kern/kern_sysctl.c:736
sys_sysctl(ffff8000fffeea78,ffff80003c3d5ae0,ffff80003c3d5a30) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80003c3d5ae0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3d5ae0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x4959a16c030, count: -10

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/31 17:37 openbsd b6d27d6c2ceb cb4e87ff .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-setuid assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c
2026/05/26 01:24 openbsd 61b7e18e5713 c69befb3 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-setuid assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c
2026/04/27 12:00 openbsd 80ba1745ccfd 0f700595 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-setuid assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c
2026/04/11 06:18 openbsd 9bac450dd51b 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c
2026/03/14 05:44 openbsd 7210d95da7cb 351cb5cf .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-setuid assert "atomic_load_int(&fdp->fd_nuserevents) == NUM" failed in kern_descrip.c
* Struck through repros no longer work on HEAD.