syzbot


assert "refs > NUM" failed in kern_synch.c

Status: upstream: reported on 2025/09/09 19:41
Reported-by: syzbot+e0d831b30701aaff71bd@syzkaller.appspotmail.com
First crash: 223d, last: 14d

Sample crash report:
panic: kernel diagnostic assertion "refs > 1" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_synch.c", line 920
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
  57829   6600  32767        0x10          0    0  syz-executor
*437162  35904  32767        0x10  0x4000000    1  syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8344eba7) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348d1af,ffffffff8346e810,398,ffffffff8345ab00) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff8000015f0008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff80003c4311d0) at if_getgroupmembers+0x11d sys/net/if.c:3256
sys_ioctl(ffff80003c42b4f0,ffff80003c4313b0,ffff80003c431300) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff80003c4313b0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4313b0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3f942c46130, 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{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: kernel diagnostic assertion "refs > 1" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_synch.c", line 920
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8344eba7) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348d1af,ffffffff8346e810,398,ffffffff8345ab00) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff8000015f0008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff80003c4311d0) at if_getgroupmembers+0x11d sys/net/if.c:3256
sys_ioctl(ffff80003c42b4f0,ffff80003c4313b0,ffff80003c431300) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff80003c4313b0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4313b0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3f942c46130, count: -8
ddb{1}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80003c431030
rbx               0xffff8000299bee07
rdx               0xffff8000015a6ac0
rcx               0xffff80003c42b4f0
rax               0xffff8000299bdff0
r8                 0x101010101010101
r9                0x8080808080808080
r10               0xc87e7362cde80e84
r11               0x2c20205e97f314a8
r12               0xffff8000299bec08
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff82c0b705    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80003c431020
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor) tid=437162 pid=35904 tcnt=2 stat=onproc
    flags process=10<SUGID> proc=4000000<THREAD>
    runpri=32, usrpri=86, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80003c42a030,0xffff80003c42ba30
    process=0xffff8000fffe4020 user=0xffff80003c42c000, vmspace=0xfffffd806c89c400
    estcpu=36, cpticks=3, pctcpu=0.0, user=0, sys=3, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
  6600   57829  36544  32767  7        0x10                syz-executor
  6600   72679  36544  32767  3   0x4000090  fsleep        syz-executor
 35904  499624  69896  32767  2        0x10                syz-executor
*35904  437162  69896  32767  7   0x4000010                syz-executor
 68684  368042  60146  32767  3        0x90  nanoslp       syz-executor
 68684  518881  60146  32767  3   0x4000090  sbwait        syz-executor
 68684   28046  60146  32767  3   0x4000090  fsleep        syz-executor
  9598   16530  60013  32767  3        0x90  nanoslp       syz-executor
  9598  202230  60013  32767  3   0x4000090  ttyin         syz-executor
  9598  231310  60013  32767  3   0x4000090  fsleep        syz-executor
 68157    3327  44861  32767  3        0x90  nanoslp       syz-executor
 68157   42346  44861  32767  3   0x4000090  fsleep        syz-executor
 68157  497748  44861  32767  3   0x4000090  fsleep        syz-executor
 39400   24727  86243      0  3    0x100082  sbwait        arp
 86243  365430  78489      0  3    0x10008a  sigsusp       sh
 60013  119651  85021  32767  3        0x90  nanoslp       syz-executor
 36544   58596   7718  32767  3        0x90  nanoslp       syz-executor
 37142   15126  23126  32767  3        0x90  wait          syz-executor
 44861  311677  70808  32767  3        0x90  nanoslp       syz-executor
 60146  209485  65395  32767  3        0x90  nanoslp       syz-executor
 69896  277466   1464  32767  3        0x90  nanoslp       syz-executor
 78489  331269  70179      0  3        0x80  wait          syz-executor
 85021  508953   6034      0  3        0x82  wait          syz-executor
  1464  392855   6034      0  3        0x82  wait          syz-executor
  7718  395256   6034      0  3        0x82  wait          syz-executor
  9441  329869   6034      0  3        0x82  wait          syz-executor
 70179  347299   6034      0  3        0x82  wait          syz-executor
 23126  148750   6034      0  3        0x82  wait          syz-executor
 70808   68315   6034      0  3        0x82  wait          syz-executor
 65395  350930   6034      0  3        0x82  wait          syz-executor
  6034  322997  75877      0  3        0x82  kqread        syz-executor
 75877  313895  84354      0  3    0x10008a  sigsusp       ksh
 84354  252839  87029      0  3        0x98  kqread        sshd-session
 87029  322752  11128      0  3        0x92  kqread        sshd-session
 97322  381982      1      0  3    0x100083  ttyin         getty
 11128  464939      1      0  3        0x88  kqread        sshd
 69748  463392  30852     73  3   0x1100090  kqread        syslogd
 30852  359654      1      0  3    0x100082  sbwait        syslogd
 63094  367382      1      0  3    0x100080  kqread        resolvd
 54592   71901  70047     77  3    0x100092  kqread        dhcpleased
 85735  461579  70047     77  3    0x100092  kqread        dhcpleased
 70047  252906      1      0  3        0x80  kqread        dhcpleased
 40125  425400      0      0  3     0x14200  bored         smr
 60394  126425      0      0  3     0x14200  pgzero        zerothread
 32186  408577      0      0  3     0x14200  aiodoned      aiodoned
 42595  219044      0      0  3     0x14200  syncer        update
 22513  127055      0      0  3     0x14200  cleaner       cleaner
 45299   27433      0      0  3     0x14200  reaper        reaper
 65110  467047      0      0  3     0x14200  pgdaemon      pagedaemon
 70843   67660      0      0  3     0x14200  bored         viomb
 78501  360405      0      0  3  0x40014200  acpi0         acpi0
 97223  183650      0      0  3  0x40014200                idle1
 47853   66131      0      0  3     0x14200  bored         softnet1
 35038  374663      0      0  3     0x14200  bored         softnet0
 59377  322933      0      0  3     0x14200  bored         systqmp
 61252   76110      0      0  3     0x14200  bored         systq
 29655  443556      0      0  3     0x14200  tmoslp        softclockmp
 32413    6703      0      0  3  0x40014200  tmoslp        softclock
 86836  194905      0      0  3  0x40014200                idle0
     1  222281      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
Process 6600 (syz-executor) thread 0xffff80003c42afc0 (72679)
exclusive rrwlock inode r = 0 (0xfffffd8075e0b688)
#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  ufs_ihashins+0x4f ufs_ihash sys/ufs/ufs/ufs_ihash.c:-1 [inline]
#4  ufs_ihashins+0x4f sys/ufs/ufs/ufs_ihash.c:159
#5  ffs_vget+0x187 sys/ufs/ffs/ffs_vfsops.c:1232
#6  ffs_inode_alloc+0x279 sys/ufs/ffs/ffs_alloc.c:393
#7  ufs_makeinode+0xcd sys/ufs/ufs/ufs_vnops.c:1732
#8  ufs_mknod+0x5b sys/ufs/ufs/ufs_vnops.c:167
#9  VOP_MKNOD+0x101 sys/kern/vfs_vops.c:121
#10 domknodat+0x469 sys/kern/vfs_syscalls.c:1659
#11 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#11 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#12 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd8075e0ba00)
#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:570
#5  vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1
#6  namei+0x7ca sys/kern/vfs_lookup.c:250
#7  domknodat+0xb4 sys/kern/vfs_syscalls.c:1611
#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 35904 (syz-executor) thread 0xffff80003c42b4f0 (437162)
shared rwlock netlock r = 0 (0xffffffff83960170)
#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_read+0x3e8 sys/kern/kern_rwlock.c:413
#2  if_getgroupmembers+0x66 sys/net/if.c:3240
#3  sys_ioctl+0x674 sys/kern/sys_generic.c:-1
#4  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#4  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#5  Xsyscall+0x128
exclusive rwlock iftmplk r = 0 (0xffffffff839600c0)
#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  if_getgroupmembers+0x51 sys/net/if.c:3238
#3  sys_ioctl+0x674 sys/kern/sys_generic.c:-1
#4  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#4  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#5  Xsyscall+0x128
ddb{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11082  12022K   12034K 166960K     12176        0
            pcb    17     12K      12K 166960K        17        0
         rtable   227      6K       6K 166960K       362        0
             pf    31     16K      16K 166960K        31        0
         ifaddr    40      7K       7K 166960K        42        0
        ifgroup    50      2K       2K 166960K        50        0
         sysctl     3      1K       9K 166960K         8        0
       counters    70     37K      37K 166960K        70        0
       ioctlops     0      0K       2K 166960K        32        0
            iov     0      0K       2K 166960K         5        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1287     81K      81K 166960K      1367        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     3      5K       5K 166960K         6        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       1K 166960K        85        0
        dirhash    12      2K       2K 166960K        18        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    26     97K     129K 166960K       289        0
          sigio     0      0K       0K 166960K         7        0
           proc    58     99K     179K 166960K       504        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     0      0K       0K 166960K        32        0
       in_multi    89      6K       6K 166960K        91        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K         7        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   241   1076K    1076K 166960K       241        0
           exec     0      0K       1K 166960K       371        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   253    145K     162K 166960K      4289        0
       UVM aobj     9      2K       2K 166960K        10        0
     pinsyscall    48     96K     116K 166960K      1341        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K         7        0
            NDP    11      0K       1K 166960K        25        0
           temp    41   9075K    9154K 166960K      4388        0
         kqueue    14     22K      29K 166960K        63        0
      SYN cache     2     16K      16K 166960K         2        0
ddb{1}> 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       43    0       38     1     0     1     1     0     8    0
rtentry    176      106    0        1     5     0     5     5     0     8    0
unpcb      144      128    0      112     2     0     2     2     0     8    1
syncache   336        5    0        5     1     0     1     1     0     8    1
tcpcb      736      134    0      130     7     0     7     7     0     8    6
arp        136       17    0        0     1     0     1     1     0     8    0
ipq         40        1    0        1     1     0     1     1     0     8    1
ipqe        40        3    0        3     1     0     1     1     0     8    1
inpcb      328      266    0      258     7     0     7     7     0     8    6
ip6q        72        1    0        0     1     0     1     1     0     8    0
ip6af       40        2    0        0     1     0     1     1     0     8    0
nd6        152       24    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      425    0        0    27     0    27    27     0     8    0
art_table   40      426    0        0     5     0     5     5     0     8    0
art_node    32      106    0       10     1     0     1     1     0     8    0
sysvmsgpl   40        3    0        2     1     0     1     1     0     8    0
semupl     112        2    0        2     1     0     1     1     0     8    1
semapl     112       79    0       69     1     0     1     1     0     8    0
shmpl      112        7    0        1     1     0     1     1     0     8    0
dirhash    1024      21    0        4     3     0     3     3     0     8    0
dino2pl    256     1789    0      329    92     0    92    92     0     8    0
ffsino     296     1789    0      329   113     0   113   113     0     8    0
nchpl      144     2200    0      513    63     0    63    63     0     8    0
vnodes     216     1870    0        0   104     0   104   104     0     8    0
namei      1024    6790    0     6790     2     0     2     2     0     8    2
percpumem   16       50    0        0     1     0     1     1     0     8    0
kstatmem   264       24    0        0     2     0     2     2     0     8    0
scxspl     216     7494    0     7494     6     1     5     5     1     8    5
plimitpl   152      121    0       95     2     0     2     2     0     8    0
sigapl     424      575    0      521     7     0     7     7     0     8    0
knotepl    120      281    0        0     9     0     9     9     0     8    0
kqueuepl   224       82    0       70     2     0     2     2     0     8    0
pipepl     344      128    0       99     3     0     3     3     0     8    0
fdescpl    528      559    0      521     4     0     4     4     0     8    0
filepl     160     2582    0     2362    12     0    12    12     0     8    1
lockfpl    104      121    0      119     1     0     1     1     0     8    0
lockfspl    48       27    0       25     1     0     1     1     0     8    0
sessionpl  144       29    0       12     1     0     1     1     0     8    0
pgrppl      48       41    0       16     1     0     1     1     0     8    0
ucredpl    104      414    0      396     1     0     1     1     0     8    0
zombiepl   144      523    0      521     1     0     1     1     0     8    0
processpl  1232     575    0      521     5     0     5     5     0     8    0
procpl     664      824    0      762     7     0     7     7     0     8    0
sockpl     752      439    0      410    10     0    10    10     0     8    6
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     113    0        0    15     0    15    15     0     8    1
mcl2k      2048      26    0        0     4     0     4     4     0     8    0
mtagpl      96        2    0        0     1     0     1     1     0     8    0
mbufpl     256      285    0        0    18     0    18    18     0     8    0
bufpl      280     2417    0      102   166     0   166   166     0     8    0
anonpl      32     7584    0        0    62     0    62    62     0   246    0
amapchunkpl 152   13043    0    12460    30     0    30    30     0   158    6
amappl16   200     2534    0     2286    18     4    14    14     0     8    0
amappl15   192        7    0        7     1     1     0     1     0     8    0
amappl14   184      399    0      396     1     0     1     1     0     8    0
amappl13   176      109    0       98     1     0     1     1     0     8    0
amappl12   168      792    0      755     2     0     2     2     0     8    0
amappl11   160        6    0        6     1     1     0     1     0     8    0
amappl10   152      167    0      157     1     0     1     1     0     8    0
amappl9    144      265    0      265     1     1     0     1     0     8    0
amappl8    136       91    0       90     1     0     1     1     0     8    0
amappl7    128      138    0      126     1     0     1     1     0     8    0
amappl6    120      149    0      147     1     0     1     1     0     8    0
amappl5    112       86    0       79     1     0     1     1     0     8    0
amappl4    104      249    0      232     1     0     1     1     0     8    0
amappl3     96     2374    0     2241     5     1     4     4     0     8    0
amappl2     88      488    0      434     2     0     2     2     0     8    0
amappl1     80     9942    0     9327    17     0    17    17     0     8    2
amappl      88     3600    0     3414     5     0     5     5     0    92    0
uvmvnodes   80      105    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        9    0        1     1     0     1     1     0     8    0
uaddrrnd    24      559    0      521     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      559    0      521     1     0     1     1     0     8    0
vmmpekpl   168     6195    0     6161     2     0     2     2     0     8    0
vmmpepl    168    44256    0    41930   106     0   106   106     0   357    4
vmsppl     488      558    0      521     7     1     6     6     0     8    0
rwobjpl     80    15705    0    14466    26     0    26    26     0     8    0
pdppl      4096    1125    0     1042   109    24    85    99     0     8    2
pvpl        32    15985    0        0   129     0   129   129     0   265    0
pmappl     256      558    0      521     4     1     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      289    0       27     8     0     8     8     0     8    0
ddb{1}> machine ddbcpu 0
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
x86_ipi_db(ffffffff838fcff0) 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(ffffffff83a0c2c0) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a0c2c0) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173
uvm_fault(fffffd806c89c218,67791d08000,0,1) at uvm_fault+0x1ea sys/uvm/uvm_fault.c:650
upageflttrap(ffff80003c416f60,67791d08000) at upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
usertrap(ffff80003c416f60) at usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x79514e24a380, count: 6
ddb{0}> trace
x86_ipi_db(ffffffff838fcff0) 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(ffffffff83a0c2c0) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a0c2c0) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173
uvm_fault(fffffd806c89c218,67791d08000,0,1) at uvm_fault+0x1ea sys/uvm/uvm_fault.c:650
upageflttrap(ffff80003c416f60,67791d08000) at upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
usertrap(ffff80003c416f60) at usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x79514e24a380, count: -9
ddb{0}> machine ddbcpu 1
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8344eba7) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348d1af,ffffffff8346e810,398,ffffffff8345ab00) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff8000015f0008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff80003c4311d0) at if_getgroupmembers+0x11d sys/net/if.c:3256
sys_ioctl(ffff80003c42b4f0,ffff80003c4313b0,ffff80003c431300) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff80003c4313b0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4313b0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3f942c46130, count: 7
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8344eba7) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348d1af,ffffffff8346e810,398,ffffffff8345ab00) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff8000015f0008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff80003c4311d0) at if_getgroupmembers+0x11d sys/net/if.c:3256
sys_ioctl(ffff80003c42b4f0,ffff80003c4313b0,ffff80003c431300) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff80003c4313b0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4313b0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3f942c46130, count: -8

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/06 19:02 openbsd 8a4a3a78bbe7 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-setuid assert "refs > NUM" failed in kern_synch.c
2026/02/09 07:36 openbsd e6ae0557afc8 018ebef2 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "refs > NUM" failed in kern_synch.c
2026/01/26 07:23 openbsd 401b985036af 55756628 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "refs > NUM" failed in kern_synch.c
2025/11/30 12:16 openbsd 0086034dedf2 01c07bfe .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "refs > NUM" failed in kern_synch.c
2025/10/23 11:36 openbsd 22e0e8faf4c6 c0460fcd .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "refs > NUM" failed in kern_synch.c
2025/09/09 19:40 openbsd 3efab2192dd6 fdeaa69b .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "refs > NUM" failed in kern_synch.c
* Struck through repros no longer work on HEAD.