syzbot


witness: reversal: sbufsnd inode (4)

Status: upstream: reported on 2026/05/23 21:30
Reported-by: syzbot+de15d066c25df21a5697@syzkaller.appspotmail.com
First crash: 57d, last: 11h20m
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd witness: reversal: sbufsnd inode (3) -1 39 179d 404d 0/4 auto-obsoleted due to no activity on 2026/04/14 02:39
openbsd witness: reversal: sbufsnd inode (2) -1 19 467d 519d 0/4 auto-obsoleted due to no activity on 2025/05/28 20:57
openbsd witness: reversal: sbufsnd inode -1 4 637d 703d 0/4 auto-obsoleted due to no activity on 2025/01/18 21:43

Sample crash report:
pf: key search, in on vio0: witness: TCPlock order reversal:
 wire: (0)  1st 0xffff800010fde7d0 sbufsnd (&so->so_snd.sb_lock)
10.128.15.235 2nd 0xfffffd00651cb318 inode (&ip->i_lock)
:30002lock order [1] sbufsnd (&so->so_snd.sb_lock) -> [2] inode (&ip->i_lock)
 lock order data 0xffffffff8351cfce -> 0xffffffff83491d2e is missing
10.128.0.39lock order [2] inode (&ip->i_lock) -> [3] sbufrcv (&so->so_rcv.sb_lock)
:29247#0  
pf: key search, in on vio0: TCP wire: (0) 10.128.15.235rw_do_enter_write:30002+0xba 
10.128.0.39#1  :29247
pf: key search, in on vio0: TCP wire: (0) 10.128.15.235sblock:30002+0xb6 
10.128.0.39#2  :29247
pf: key search, out on vio0: soreceiveTCP+0x27d wire: (0) 
10.128.15.235#3  :30002 10.128.0.39:29247
fifo_read+0x117
#4  VOP_READ+0x101 sys/kern/vfs_vops.c:227
#5  vn_rdwr+0x15b sys/kern/vfs_vnops.c:-1
#6  vndsetcred+0xa1 sys/dev/vnd.c:685
#7  vndioctl+0xdfc sys/dev/vnd.c:486
#8  VOP_IOCTL+0xac sys/kern/vfs_vops.c:264
#9  vn_ioctl+0xf8 sys/kern/vfs_vnops.c:537
#10 sys_ioctl+0x674 sys/kern/sys_generic.c:-1
#11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#12 Xsyscall+0x128
lock order [3] sbufrcv (&so->so_rcv.sb_lock) -> [1] sbufsnd (&so->so_snd.sb_lock)
#0  rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234
#1  sblock+0xb6 sys/kern/uipc_socket2.c:536
#2  sosplice+0x32b sys/kern/uipc_socket.c:1352
#3  sys_setsockopt+0x2ba sys/kern/uipc_syscalls.c:1226
#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
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
the kernel did not panic
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
witness_checkorder(fffffd00651cb318,9,0) at witness_checkorder+0x10d1 sys/kern/subr_witness.c:-1
rw_do_enter_write(fffffd00651cb300,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234
rrw_enter(fffffd00651cb300,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
VOP_LOCK(fffffd006a1b97b0,2001) at VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
vn_lock(fffffd006a1b97b0,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:576
vfs_lookup(ffff80003739c3a0) at vfs_lookup+0x12b sys/kern/vfs_lookup.c:431
namei(ffff80003739c3a0) at namei+0x7c5 sys/kern/vfs_lookup.c:250
unp_connect(ffff800010fde5e8,fffffd006db31a00,ffff800045ffc7d0) at unp_connect+0x29d sys/kern/uipc_usrreq.c:872
uipc_dgram_send(ffff800010fde5e8,fffffd006d8e2800,fffffd006db31a00,0) at uipc_dgram_send+0x163 sys/kern/uipc_usrreq.c:609
sosend(ffff800010fde5e8,fffffd006db31a00,ffff80003739c628,0,0,400) at sosend+0x804 sys/kern/uipc_socket.c:-1
sendit(ffff800045ffc7d0,6,ffff80003739c720,400,ffff80003739c7d0) at sendit+0x5a5 sys/kern/uipc_syscalls.c:785
sys_sendto(ffff800045ffc7d0,ffff80003739c880,ffff80003739c7d0) at sys_sendto+0x8d sys/kern/uipc_syscalls.c:563
syscall(ffff80003739c880) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003739c880) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x311f8ffa350, count: -15
ddb{0}> show registers
rdi                                0
rsi                          0x80000    acpi_pdirpa+0x6be71
rbp               0xffff80003739c010
rbx                                0
rdx               0xffff8000015fcd40
rcx               0xffff800045ffc7d0
rax                          0x7ffff    acpi_pdirpa+0x6be70
r8                0xffff80003739bef0
r9                0x8080808080808080
r10               0xbb89e38b406c3473
r11               0xeef4a2acf1c900db
r12               0xfffffd00040c2980
r13               0xfffffd00048aa460
r14                              0x3
r15               0xffffffff83527de9    substchar+0xa606
rip               0xffffffff82bc5d85    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80003739c000
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor) tid=100122 pid=99709 tcnt=2 stat=onproc
    flags process=10<SUGID> proc=4000000<THREAD>
    runpri=32, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a223768,0xffffffff83a572e0
    process=0xffff800045fe6b70 user=0xffff800037397000, vmspace=0xfffffd006bfc93f0
    estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 99709  225286  62920     -1  2        0x10                syz-executor
*99709  100122  62920     -1  7   0x4000010                syz-executor
  5109   67936  78681      0  2        0x10                syz-executor
  5109   11722  78681      0  3   0x4000090  fsleep        syz-executor
 84286   55592  22696      0  2           0                syz-executor
 84286  400728  22696      0  3   0x4000080  sbwait        syz-executor
 84286   53055  22696      0  3   0x4000080  fsleep        syz-executor
 81080  512192  44848      0  2           0                syz-executor
 81080   80679  44848      0  3   0x4000080  fsleep        syz-executor
 39468  240561  94856      0  2           0                syz-executor
 39468  392611  94856      0  2   0x4000000                syz-executor
 39468  333504  94856      0  3   0x4000080  fsleep        syz-executor
 31786   30996  72324      0  2           0                syz-executor
 31786   16816  72324      0  3   0x4000080  fsleep        syz-executor
 99596  371409  66015      0  2           0                syz-executor
 99596  239560  66015      0  7   0x4000000                syz-executor
 99596  394459  66015      0  3   0x4000000  inode         syz-executor
 90504   30797      1      0  3    0x100083  ttyin         getty
 62920  366831  98745      0  3        0x82  nanoslp       syz-executor
 94856   54349  98745      0  3        0x82  nanoslp       syz-executor
 44848  163559  98745      0  3        0x82  nanoslp       syz-executor
 66015   89858  98745      0  3        0x82  nanoslp       syz-executor
 78681  203829  98745      0  3        0x82  nanoslp       syz-executor
 97540  395649  98745      0  2         0x2                syz-executor
 22696  514042  98745      0  3        0x82  nanoslp       syz-executor
 72324  122644  98745      0  2         0x2                syz-executor
 98745  225816      1      0  2         0x2                syz-executor
 84212  401581      0      0  3     0x14200  bored         smr
 34031   37051      0      0  2     0x14200                zerothread
 45995  503330      0      0  3     0x14200  aiodoned      aiodoned
 20368  342514      0      0  3     0x14200  syncer        update
 94880  219735      0      0  3     0x14200  cleaner       cleaner
 91168   77138      0      0  3     0x14200  reaper        reaper
 70628    6770      0      0  3     0x14200  pgdaemon      pagedaemon
 67674   68466      0      0  3     0x14200  bored         viomb
 46793  283420      0      0  3  0x40014200  acpi0         acpi0
 80820  162734      0      0  3  0x40014200                idle1
 62176  174194      0      0  3     0x14200  bored         softnet1
 16448   87732      0      0  3     0x14200  bored         softnet0
 26825  252548      0      0  3     0x14200  bored         systqmp
  3358   17186      0      0  3     0x14200  syncxs        systq
 75370  467175      0      0  3     0x14200  tmoslp        softclockmp
 64528  196589      0      0  3  0x40014200  tmoslp        softclock
 77630  245878      0      0  3  0x40014200                idle0
     1  139617      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
Process 99709 (syz-executor) thread 0xffff800045ffc7d0 (100122)
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83b41300)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  unp_connect+0x28c sys/kern/uipc_usrreq.c:872
#2  uipc_dgram_send+0x163 sys/kern/uipc_usrreq.c:609
#3  sosend+0x804 sys/kern/uipc_socket.c:-1
#4  sendit+0x5a5 sys/kern/uipc_syscalls.c:785
#5  sys_sendto+0x8d sys/kern/uipc_syscalls.c:563
#6  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#6  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#7  Xsyscall+0x128
exclusive rwlock sbufsnd r = 0 (0xffff800010fde7d0)
#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  sblock+0xb6 sys/kern/uipc_socket2.c:536
#3  sosend+0x2e9 sys/kern/uipc_socket.c:639
#4  sendit+0x5a5 sys/kern/uipc_syscalls.c:785
#5  sys_sendto+0x8d sys/kern/uipc_syscalls.c:563
#6  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#6  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#7  Xsyscall+0x128
Process 99596 (syz-executor) thread 0xffff800045ffd9f8 (239560)
exclusive rrwlock inode r = 0 (0xfffffd00651cb1f0)
#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  vn_write+0x18f sys/kern/vfs_vnops.c:411
#6  dofilewritev+0x2bd sys/kern/sys_generic.c:384
#7  sys_write+0xa2 sys/kern/sys_generic.c:300
#8  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#9  Xsyscall+0x128
Process 3358 (systq) thread 0xffff800045ffe530 (17186)
shared rwlock systq r = 0 (0xffffffff838d67a8)
#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 11068  12145K   12339K 166960K     12500        0
            pcb    17     12K      12K 166960K        68        0
         rtable   250      8K       8K 166960K       387        0
             pf    40     18K      24K 166960K        90        0
         ifaddr    44      7K       7K 166960K        53        0
        ifgroup    57      2K       2K 166960K        69        0
         sysctl     3      1K       9K 166960K        10        0
       counters    72     37K      37K 166960K        86        0
       ioctlops     0      0K       4K 166960K      1538        0
            iov     0      0K      16K 166960K         9        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1363     86K      86K 166960K      1584        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       9K 166960K         9        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K        23        0
        dirhash    12      2K       2K 166960K        15        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    16     61K      97K 166960K       339        0
          sigio     0      0K       0K 166960K         5        0
           proc    21     33K     180K 166960K       577        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        13        0
       in_multi    99      7K       7K 166960K       105        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     1      0K       0K 166960K         9        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       407        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   133     82K     177K 166960K      4923        0
       UVM aobj    14      4K       4K 166960K        15        0
     pinsyscall    19     38K     108K 166960K      1499        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        11        0
            NDP    13      0K       2K 166960K        34        0
           temp    74   9127K    9163K 166960K     10039        0
         kqueue     1      2K      27K 166960K        65        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
vscsiccb    40        1    0        0     1     0     1     1     0     8    0
plcache    128       28    0        0     1     0     1     1     0     8    0
rtpcb      120       41    0       41     1     0     1     1     0     8    1
rtentry    176      119    0        7     6     0     6     6     0     8    0
unpcb      144      121    0      117     1     0     1     1     0     8    0
syncache   336        5    0        4     2     1     1     1     0     8    0
tcpcb      736       54    0       51     1     0     1     1     0     8    0
arp        136       20    0        2     1     0     1     1     0     8    0
inpcb      328      218    0      214     3     1     2     2     0     8    1
nd6        152       26    0        0     1     0     1     1     0     8    0
pkpcb       40        2    0        2     1     0     1     1     0     8    1
kcovpl      48        8    0        0     1     0     1     1     0     8    0
ppxss      1192       7    0        6     1     0     1     1     0     8    0
pfstscr     40       12    0       10     1     0     1     1     0     8    0
pffrag     232        1    0        0     1     0     1     1     0   482    0
pffrnode    88        1    0        0     1     0     1     1     0     8    0
pffrent     40        1    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
pfanchor   1288       4    0        1     1     0     1     1     0     8    0
pfstitem    24       39    0        0     1     0     1     1     0     8    0
pfstkey    128       49    0       10     2     0     2     2     0     8    0
pfstate    448       42    0        5     5     0     5     5     0     8    0
pfrule     1360      23    0       18     2     1     1     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      478    0        7    30     0    30    30     0     8    0
art_table   40      479    0        7     5     0     5     5     0     8    0
art_node    32      119    0       17     1     0     1     1     0     8    0
sysvmsgpl   40        5    0        5     1     0     1     1     0     8    1
semupl     112        2    0        2     2     1     1     1     0     8    1
semapl      72       19    0        9     1     0     1     1     0     8    0
shmpl      112       12    0        1     1     0     1     1     0     8    0
dirhash    1024      19    0        2     3     0     3     3     0     8    0
dino2pl    256     1925    0      452    93     0    93    93     0     8    0
ffsino     296     1925    0      452   115     0   115   115     0     8    1
nchpl      144     2394    0      689    64     0    64    64     0     8    0
rtmask      32        1    0        1     1     0     1     1     0     8    1
vnodes     216     2177    0        0   121     0   121   121     0     8    0
namei      1024    7573    0     7572     4     2     2     2     0     8    1
percpumem   16       59    0        7     1     0     1     1     0     8    0
kstatmem   264       39    0       10     3     0     3     3     0     8    1
scxspl     216     9844    0     9843     4     3     1     3     1     8    0
plimitpl   152       82    0       70     1     0     1     1     0     8    0
sigapl     424      657    0      622     7     1     6     7     0     8    0
knotepl    120      544    0        0    17     0    17    17     0     8    0
kqueuepl   224       79    0       78     1     0     1     1     0     8    0
pipepl     344      138    0      111     3     0     3     3     0     8    0
fdescpl    528      641    0      622     3     0     3     3     0     8    0
filepl     160     2678    0     2511    13     1    12    12     0     8    2
lockfpl    104      206    0      206     2     0     2     2     0     8    2
lockfspl    48       99    0       99     1     0     1     1     0     8    1
sessionpl  144       30    0       27     1     0     1     1     0     8    0
pgrppl      48       41    0       30     1     0     1     1     0     8    0
ucredpl    104      283    0      278     1     0     1     1     0     8    0
zombiepl   144      622    0      622     2     1     1     1     0     8    1
processpl  1232     657    0      622     5     0     5     5     0     8    0
procpl     664     1000    0      955     7     1     6     6     0     8    1
sosppl     176        1    0        1     1     0     1     1     0     8    1
sockpl     752      389    0      381     4     0     4     4     0     8    2
mcl64k     65536      2    0        0     1     0     1     1     0     8    0
mcl8k      8192       2    0        0     1     0     1     1     0     8    0
mcl4k      4096     112    0        0    14     0    14    14     0     8    0
mcl2k      2048      28    0        0     4     0     4     4     0     8    0
mextrefs    64       28    0        0     1     0     1     1     0     8    0
mtagpl      96        2    0        0     1     0     1     1     0     8    0
mbufpl     256      172    0        0    11     0    11    11     0     8    0
bufpl      272     4344    0      107   283     0   283   283     0     8    0
anonpl      32     7416    0        0    60     0    60    60     0   247    0
amapchunkpl 152   14744    0    14391    25     3    22    24     0   158    4
amappl16   200     2402    0     2350    23    12    11    14     0     8    7
amappl15   192       80    0       80     1     1     0     1     0     8    0
amappl14   184      451    0      451     1     0     1     1     0     8    1
amappl13   176      126    0      125     1     0     1     1     0     8    0
amappl12   168      890    0      872     2     0     2     2     0     8    0
amappl11   160        7    0        6     1     0     1     1     0     8    0
amappl10   152       64    0       64     1     0     1     1     0     8    1
amappl9    144      275    0      274     2     1     1     1     0     8    0
amappl8    136      123    0      123     1     0     1     1     0     8    1
amappl7    128      195    0      192     1     0     1     1     0     8    0
amappl6    120      154    0      154     1     0     1     1     0     8    1
amappl5    112       98    0       97     1     0     1     1     0     8    0
amappl4    104      293    0      290     1     0     1     1     0     8    0
amappl3     96     2848    0     2769     5     1     4     4     0     8    1
amappl2     88      548    0      538     2     0     2     2     0     8    0
amappl1     80    11319    0    11202    15     2    13    15     0     8    8
amappl      88     4101    0     3982     4     0     4     4     0    92    0
uvmvnodes   80      107    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       14    0        1     1     0     1     1     0     8    0
uaddrrnd    24      641    0      622     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      641    0      622     1     0     1     1     0     8    0
vmmpekpl   168     7163    0     7127     2     0     2     2     0     8    0
vmmpepl    168    50494    0    49624    95     9    86    94     0   357   39
vmsppl     488      640    0      622     5     1     4     5     0     8    0
rwobjpl     80    17254    0    16789    26     2    24    26     0     8    1
pdppl      4096    1289    0     1244    99    50    49    87     0     8    4
pvpl        32    13525    0        0   110     0   110   110     0   265    0
pmappl     256      640    0      622     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      560    0       56    15     0    15    15     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
witness_checkorder(fffffd00651cb318,9,0) at witness_checkorder+0x10d1 sys/kern/subr_witness.c:-1
rw_do_enter_write(fffffd00651cb300,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234
rrw_enter(fffffd00651cb300,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
VOP_LOCK(fffffd006a1b97b0,2001) at VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
vn_lock(fffffd006a1b97b0,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:576
vfs_lookup(ffff80003739c3a0) at vfs_lookup+0x12b sys/kern/vfs_lookup.c:431
namei(ffff80003739c3a0) at namei+0x7c5 sys/kern/vfs_lookup.c:250
unp_connect(ffff800010fde5e8,fffffd006db31a00,ffff800045ffc7d0) at unp_connect+0x29d sys/kern/uipc_usrreq.c:872
uipc_dgram_send(ffff800010fde5e8,fffffd006d8e2800,fffffd006db31a00,0) at uipc_dgram_send+0x163 sys/kern/uipc_usrreq.c:609
sosend(ffff800010fde5e8,fffffd006db31a00,ffff80003739c628,0,0,400) at sosend+0x804 sys/kern/uipc_socket.c:-1
sendit(ffff800045ffc7d0,6,ffff80003739c720,400,ffff80003739c7d0) at sendit+0x5a5 sys/kern/uipc_syscalls.c:785
sys_sendto(ffff800045ffc7d0,ffff80003739c880,ffff80003739c7d0) at sys_sendto+0x8d sys/kern/uipc_syscalls.c:563
syscall(ffff80003739c880) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003739c880) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x311f8ffa350, count: -15
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
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
__mp_lock(ffffffff83b40b00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83b40b00) at __mp_lock+0x192 sys/kern/kern_lock.c:173
__mp_acquire_count(ffffffff83b40b00,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1
sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:369
biowait(fffffd006ceaa550) at biowait+0xc6 sys/kern/vfs_bio.c:1110
bwrite(fffffd006ceaa550) at bwrite+0x359 sys/kern/vfs_bio.c:625
ffs_write(ffff80002a2291b0) at ffs_write+0x810 sys/ufs/ffs/ffs_vnops.c:377
VOP_WRITE(fffffd006399d448,ffff80002a229368,7,fffffd00097fd208) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
vn_write(fffffd00632c84c0,ffff80002a229368,0) at vn_write+0x1d3 sys/kern/vfs_vnops.c:414
dofilewritev(ffff800045ffd9f8,3,ffff80002a229368,0,ffff80002a229420) at dofilewritev+0x2bd sys/kern/sys_generic.c:384
sys_write(ffff800045ffd9f8,ffff80002a2294d0,ffff80002a229420) at sys_write+0xa2 sys/kern/sys_generic.c:300
syscall(ffff80002a2294d0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2294d0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x358e95780e0, count: -15
ddb{1}> 

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/12 13:38 openbsd e38f82204f65 d78ea535 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore witness: reversal: sbufsnd inode
2026/07/03 23:06 openbsd 2f91687338ee aa437a8a .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore witness: reversal: sbufsnd inode
2026/06/26 06:21 openbsd a5986fc34424 7ff32d8b .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore witness: reversal: sbufsnd inode
2026/06/26 00:02 openbsd a5986fc34424 7ff32d8b .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore witness: reversal: sbufsnd inode
2026/06/22 13:04 openbsd a1ed62b580c9 62cc6db3 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore witness: reversal: sbufsnd inode
2026/05/23 21:29 openbsd 19a8be4fa5c4 c69befb3 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore witness: reversal: sbufsnd inode
2026/07/20 05:17 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan 7db9963a4e65 72524a66 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan witness: reversal: sbufsnd inode
2026/07/16 10:40 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan b0ea410f6c4b 851bd571 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan witness: reversal: sbufsnd inode
2026/07/13 18:16 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan dbfd7807b1e0 a870962e .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan witness: reversal: sbufsnd inode
2026/07/10 06:43 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan 275dedaf93b0 4167ee25 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan witness: reversal: sbufsnd inode
* Struck through repros no longer work on HEAD.