syzbot


uvm_fault: ffs_nodealloccg (4)

Status: upstream: reported on 2026/03/29 00:14
Reported-by: syzbot+18c0da8db2b18571ff77@syzkaller.appspotmail.com
First crash: 19d, last: 14d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd uvm_fault: ffs_nodealloccg -1 1 1543d 1543d 0/3 auto-closed as invalid on 2022/04/24 17:10
openbsd uvm_fault: ffs_nodealloccg (2) -1 2 579d 580d 0/3 auto-obsoleted due to no activity on 2024/12/13 04:19
openbsd uvm_fault: ffs_nodealloccg (3) -1 1 202d 202d 0/3 auto-obsoleted due to no activity on 2025/12/25 04:08

Sample crash report:
uvm_fault(0xffffffff83ab44f0, 0xffff800025d22004, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ffs_nodealloccg+0x13c:  movl    0x4(%rbx),%r15d
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*464485  27215      0         0x2          0    1K syz-executor
 484036  89747      0         0x2        0x1    0  syz-executor
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c ffs_cgread sys/ufs/ffs/ffs_alloc.c:856 [inline]
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c sys/ufs/ffs/ffs_alloc.c:1106
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a ffs_hashalloc sys/ufs/ffs/ffs_alloc.c:814 [inline]
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a sys/ufs/ffs/ffs_alloc.c:390
ufs_mkdir(ffff80002a3462a0) at ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112
VOP_MKDIR(fffffd8072f678a0,ffff80002a346400,ffff80002a346430,ffff80002a346330) at VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394
domkdirat(ffff8000ffff3ca0,ffffff9c,71c0cf02fda0,1c0) at domkdirat+0x179 sys/kern/vfs_syscalls.c:3143
syscall(ffff80002a3465b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a3465b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71c0cf02fd60, count: 8
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: uvm_fault(0xffffffff83ab44f0, 0xffff800025d22004, 0, 1) -> d
ddb{1}> trace
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c ffs_cgread sys/ufs/ffs/ffs_alloc.c:856 [inline]
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c sys/ufs/ffs/ffs_alloc.c:1106
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a ffs_hashalloc sys/ufs/ffs/ffs_alloc.c:814 [inline]
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a sys/ufs/ffs/ffs_alloc.c:390
ufs_mkdir(ffff80002a3462a0) at ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112
VOP_MKDIR(fffffd8072f678a0,ffff80002a346400,ffff80002a346430,ffff80002a346330) at VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394
domkdirat(ffff8000ffff3ca0,ffffff9c,71c0cf02fda0,1c0) at domkdirat+0x179 sys/kern/vfs_syscalls.c:3143
syscall(ffff80002a3465b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a3465b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71c0cf02fd60, count: -7
ddb{1}> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a346050
rbx               0xffff800025d22000
rdx                                0
rcx               0xffff8000ffff3ca0
rax               0xffff8000299bdff0
r8                0xffffffffffffffff
r9                0xfffffd80097fd1a0
r10               0x5b5a4aeb204b5e4e
r11               0xe883808b5c8cc8ad
r12               0xffff800000c31800
r13               0xfffffd806025d350
r14                                0
r15                                0
rip               0xffffffff821e4cdc    ffs_nodealloccg+0x13c
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002a345fa0
ss                              0x10
ffs_nodealloccg+0x13c:  movl    0x4(%rbx),%r15d
ddb{1}> show proc
PROC (syz-executor) tid=464485 pid=27215 tcnt=1 stat=onproc
    flags process=2<EXEC> proc=0
    runpri=36, usrpri=50, slppri=36, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002eba6a88,0xffffffff83ab4ec8
    process=0xffff8000fffef038 user=0xffff80002a341000, vmspace=0xfffffd806c8b93e8
    estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=1, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
*27215  464485  89747      0  7         0x2                syz-executor
  3375  306943      1      0  3    0x100083  ttyin         getty
 82845  316880  20682      0  3    0x100082  sbwait        ndp
 20682  117118  23201      0  3    0x10008a  sigsusp       sh
 23201  185813  89747      0  3        0x82  wait          syz-executor
 89747  484036  18706      0  7         0x3                syz-executor
 18706  160325  40622      0  3    0x10008a  sigsusp       ksh
 40622  470215    653      0  3        0x98  kqread        sshd-session
   653  187203  45458      0  3        0x92  kqread        sshd-session
 45458  149723      1      0  3        0x88  kqread        sshd
 29014   92740  21833     74  3   0x1100092  bpf           pflogd
 21833  120157      1      0  3        0x80  sbwait        pflogd
 53626  155110  27047     73  3   0x1100090  kqread        syslogd
 27047   37051      1      0  3    0x100082  sbwait        syslogd
  5411  131919      1      0  3    0x100080  kqread        resolvd
 51563  149112  82998     77  3    0x100092  kqread        dhcpleased
 96482  246724  82998     77  3    0x100092  kqread        dhcpleased
 82998  276119      1      0  3        0x80  kqread        dhcpleased
 34884   12896      0      0  3     0x14200  bored         smr
 21704  315093      0      0  3     0x14200  pgzero        zerothread
 18570  499714      0      0  3     0x14200  aiodoned      aiodoned
 16124  449118      0      0  3     0x14200  syncer        update
 13440   72231      0      0  3     0x14200  cleaner       cleaner
 89753  234368      0      0  3     0x14200  reaper        reaper
 68924  343554      0      0  3     0x14200  pgdaemon      pagedaemon
  2100  223368      0      0  3     0x14200  bored         viomb
 32690  377806      0      0  3  0x40014200  acpi0         acpi0
 97462   85119      0      0  3  0x40014200                idle1
 76809  504653      0      0  3     0x14200  bored         softnet1
 57454  448993      0      0  3     0x14200  bored         softnet0
 47496  437259      0      0  3     0x14200  smrbar        systqmp
 97834  421545      0      0  3     0x14200  bored         systq
 45072  358658      0      0  3     0x14200  tmoslp        softclockmp
 97363  142070      0      0  3  0x40014200  tmoslp        softclock
 88806  207632      0      0  3  0x40014200                idle0
     1  121259      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
Process 27215 (syz-executor) thread 0xffff8000ffff3ca0 (464485)
exclusive rrwlock inode r = 0 (0xfffffd806f8aea18)
#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  domkdirat+0x8b sys/kern/vfs_syscalls.c:3128
#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
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a4a780)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
#1  syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783
#2  Xsyscall+0x128
Process 47496 (systqmp) thread 0xffff8000ffffe530 (437259)
shared rwlock systqmp r = 0 (0xffffffff839418f8)
#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{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11061  12096K   12446K 166960K     12735        0
            pcb    17     13K      14K 166960K       150        0
         rtable   209     10K      11K 166960K       491        0
             pf    32     17K      81K 166960K       204        0
         ifaddr    36      6K       8K 166960K        64        0
        ifgroup    44      1K       2K 166960K        83        0
         sysctl     4      1K       9K 166960K        12        0
       counters    66     36K      37K 166960K       102        0
       ioctlops     0      0K       4K 166960K      1632        0
            iov     0      0K      28K 166960K        36        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1292     81K      82K 166960K      1809        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K         5        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K        36        0
        dirhash    12      2K       2K 166960K        24        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    11     34K      85K 166960K       721        0
          sigio     0      0K       0K 166960K         4        0
           proc    72    115K     147K 166960K       630        0
        subproc    54      3K       4K 166960K        83        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       135        0
       in_multi    74      5K       7K 166960K       121        0
    ether_multi     1      0K       0K 166960K         5        0
            mrt     0      0K       0K 166960K        21        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    91    413K     413K 166960K        91        0
           exec     0      0K       1K 166960K       495        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   177    135K     171K 166960K      8608        0
       UVM aobj    93      7K       7K 166960K        97        0
     pinsyscall    37     74K     103K 166960K      1925        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        39        0
            NDP    10      0K       1K 166960K        42        0
           temp    72   9087K    9156K 166960K     23105        0
         kqueue    13     20K      30K 166960K       130        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       86    0       82     1     0     1     1     0     8    0
rtentry    176      143    0       60     5     0     5     5     0     8    0
unpcb      144      400    0      383     3     1     2     2     0     8    1
syncache   336        9    0        9     1     0     1     1     0     8    1
tcpcb      736      268    0      264     7     3     4     7     0     8    3
arp        136       25    0        7     1     0     1     1     0     8    0
inpcb      328      787    0      779    15     6     9    12     0     8    8
nd6        152       28    0       10     1     0     1     1     0     8    0
pkpcb       40        4    0        4     1     0     1     1     0     8    1
kcovpl      48        9    0        3     1     0     1     1     0     8    0
ppxss      1192      13    0       13     1     0     1     1     0     8    1
pppxif     1576       1    0        1     1     1     0     1     0     8    0
pfstscr     40        3    0        2     1     0     1     1     0     8    0
pffrag     232        7    0        2     1     0     1     1     0   482    0
pffrnode    88        7    0        2     1     0     1     1     0     8    0
pffrent     40       13    0        8     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
pfrktable  1344       5    0        5     2     1     1     1     0     8    1
pfsrclim   320        2    0        2     1     0     1     1     0     8    1
pfanchor   1288       4    0        1     1     0     1     1     0     8    0
pfstitem    24       59    0       11     1     0     1     1     0     8    0
pfstkey    128       63    0       15     2     0     2     2     0     8    0
pfstate    448       59    0       13     6     0     6     6     0     8    0
pfrule     1360      58    0       52     2     1     1     2     0     8    0
art_heap8  4096       2    0        0     2     0     2     2     0     8    0
art_heap4  256      568    0      175    29     4    25    29     0     8    0
art_table   40      570    0      175     5     0     5     5     0     8    0
art_node    32      140    0       58     1     0     1     1     0     8    0
sysvmsgpl   40        2    0        1     1     0     1     1     0     8    0
semupl     112        1    0        1     1     1     0     1     0     8    0
semapl     112       32    0       22     1     0     1     1     0     8    0
shmpl      112       94    0        4     3     0     3     3     0     8    0
dirhash    1024      25    0        8     3     0     3     3     0     8    0
dino2pl    256     2661    0     1207    93     0    93    93     0     8    0
ffsino     296     2662    0     1208   114     0   114   114     0     8    0
nchpl      144     3670    0     1967    64     0    64    64     0     8    0
rtmask      32        3    0        3     2     1     1     1     0     8    1
vnodes     216     2983    0        0   166     0   166   166     0     8    0
namei      1024   12068    0    12067     3     1     2     2     0     8    1
percpumem   16       66    0       18     1     0     1     1     0     8    0
pfiaddrpl  120        1    0        1     1     0     1     1     0     8    1
kstatmem   264       46    0       24     3     1     2     3     0     8    0
scsiplug    72        2    0        2     1     0     1     1     0     8    1
scxspl     216    29863    0    29863    11     3     8     8     1     8    8
plimitpl   152      218    0      201     1     0     1     1     0     8    0
sigapl     424     1039    0      997     6     0     6     6     0     8    0
knotepl    120      555    0        0    17     0    17    17     0     8    0
kqueuepl   224      202    0      193     2     0     2     2     0     8    1
pipepl     344      167    0      140     3     0     3     3     0     8    0
fdescpl    528     1023    0      998     3     0     3     3     0     8    0
filepl     160     5702    0     5521    18     1    17    17     0     8    7
lockfpl    104      241    0      239     1     0     1     1     0     8    0
lockfspl    48      102    0      100     1     0     1     1     0     8    0
sessionpl  144       79    0       70     1     0     1     1     0     8    0
pgrppl      48       94    0       77     1     0     1     1     0     8    0
ucredpl    104      742    0      728     1     0     1     1     0     8    0
zombiepl   144     1003    0      997     1     0     1     1     0     8    0
processpl  1232    1039    0      997     5     0     5     5     0     8    0
procpl     664     2042    0     2000     6     0     6     6     0     8    0
sosppl     176        2    0        2     1     0     1     1     0     8    1
sockpl     752     1301    0     1272    20     9    11    17     0     8    7
mcl64k     65536      6    0        0     1     0     1     1     0     8    0
mcl16k     16384      7    0        0     1     0     1     1     0     8    0
mcl12k     12288      1    0        0     1     0     1     1     0     8    0
mcl8k      8192       3    0        0     1     0     1     1     0     8    0
mcl4k      4096     109    0        0    14     0    14    14     0     8    0
mcl2k      2048      33    0        0     5     0     5     5     0     8    0
mtagpl      96        9    0        0     1     0     1     1     0     8    0
mbufpl     256      200    0        0    13     0    13    13     0     8    0
bufpl      280    13213    0     7083   439     0   439   439     0     8    0
anonpl      32    12701    0        0   103     0   103   103     0   246    0
amapchunkpl 152   35652    0    35372    45     9    36    37     0   158   18
amappl16   200     5088    0     5069    47    20    27    31     0     8   21
amappl15   192       10    0       10     1     1     0     1     0     8    0
amappl14   184      439    0      437     1     0     1     1     0     8    0
amappl13   176      134    0      121     1     0     1     1     0     8    0
amappl12   168     1285    0     1262     2     0     2     2     0     8    0
amappl11   160       27    0       27     1     1     0     1     0     8    0
amappl10   152       66    0       52     1     0     1     1     0     8    0
amappl9    144      281    0      281     1     1     0     1     0     8    0
amappl8    136      121    0      118     1     0     1     1     0     8    0
amappl7    128      157    0      143     1     0     1     1     0     8    0
amappl6    120      194    0      192     1     0     1     1     0     8    0
amappl5    112      108    0       98     1     0     1     1     0     8    0
amappl4    104      319    0      296     1     0     1     1     0     8    0
amappl3     96     5529    0     5460     4     0     4     4     0     8    0
amappl2     88      604    0      539     2     0     2     2     0     8    0
amappl1     80    13543    0    12944    17     0    17    17     0     8    2
amappl      88     7715    0     7612     5     0     5     5     0    92    0
uvmvnodes   80      131    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        8    0        8     3     3     0     1     0     8    0
dma128     128      254    0      254     2     1     1     1     0     8    1
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       19    0       18     1     0     1     1     0     8    0
aobjpl      72       96    0        4     2     0     2     2     0     8    0
uaddrrnd    24     1023    0      998     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1023    0      998     1     0     1     1     0     8    0
vmmpekpl   168    10209    0    10162     3     0     3     3     0     8    0
vmmpepl    168    76744    0    75193   120     1   119   119     0   357   23
vmsppl     488     1022    0      998     5     0     5     5     0     8    0
rwobjpl     80    25110    0    24007    38     0    38    38     0     8    2
pdppl      4096    2053    0     1996   107    30    77    81     0     8   20
pvpl        32    20582    0        0   166     0   166   166     0   265    0
pmappl     256     1022    0      998     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      296    0       43     8     0     8     8     0     8    0
ddb{1}> machine ddbcpu 0
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
x86_ipi_db(ffffffff83931ff0) 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(ffffffff83a49f80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a49f80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83
dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
__mp_lock(ffffffff83a49f80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a49f80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
ktrgenio(ffff80002a2422a8,18,0,ffff800000c407d0,1e) at ktrgenio+0x228 ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrgenio(ffff80002a2422a8,18,0,ffff800000c407d0,1e) at ktrgenio+0x228 sys/kern/kern_ktrace.c:264
dofilereadv(ffff80002a2422a8,18,ffff80002a2b41f8,0,ffff80002a2b42b0) at dofilereadv+0x474 sys/kern/sys_generic.c:268
sys_read(ffff80002a2422a8,ffff80002a2b4360,ffff80002a2b42b0) at sys_read+0xa2 sys/kern/sys_generic.c:172
syscall(ffff80002a2b4360) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2b4360) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e4b91e5dec0, count: 2
ddb{0}> trace
x86_ipi_db(ffffffff83931ff0) 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(ffffffff83a49f80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a49f80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83
dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
__mp_lock(ffffffff83a49f80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a49f80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
ktrgenio(ffff80002a2422a8,18,0,ffff800000c407d0,1e) at ktrgenio+0x228 ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrgenio(ffff80002a2422a8,18,0,ffff800000c407d0,1e) at ktrgenio+0x228 sys/kern/kern_ktrace.c:264
dofilereadv(ffff80002a2422a8,18,ffff80002a2b41f8,0,ffff80002a2b42b0) at dofilereadv+0x474 sys/kern/sys_generic.c:268
sys_read(ffff80002a2422a8,ffff80002a2b4360,ffff80002a2b42b0) at sys_read+0xa2 sys/kern/sys_generic.c:172
syscall(ffff80002a2b4360) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2b4360) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e4b91e5dec0, count: -13
ddb{0}> machine ddbcpu 1
Stopped at      ffs_nodealloccg+0x13c:  movl    0x4(%rbx),%r15d
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c ffs_cgread sys/ufs/ffs/ffs_alloc.c:856 [inline]
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c sys/ufs/ffs/ffs_alloc.c:1106
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a ffs_hashalloc sys/ufs/ffs/ffs_alloc.c:814 [inline]
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a sys/ufs/ffs/ffs_alloc.c:390
ufs_mkdir(ffff80002a3462a0) at ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112
VOP_MKDIR(fffffd8072f678a0,ffff80002a346400,ffff80002a346430,ffff80002a346330) at VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394
domkdirat(ffff8000ffff3ca0,ffffff9c,71c0cf02fda0,1c0) at domkdirat+0x179 sys/kern/vfs_syscalls.c:3143
syscall(ffff80002a3465b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a3465b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71c0cf02fd60, count: 8
ddb{1}> trace
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c ffs_cgread sys/ufs/ffs/ffs_alloc.c:856 [inline]
ffs_nodealloccg(fffffd806f8ae978,0,0,41c0) at ffs_nodealloccg+0x13c sys/ufs/ffs/ffs_alloc.c:1106
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a ffs_hashalloc sys/ufs/ffs/ffs_alloc.c:814 [inline]
ffs_inode_alloc(fffffd806f8ae978,41c0,fffffd80097fd1a0,ffff80002a346238) at ffs_inode_alloc+0x20a sys/ufs/ffs/ffs_alloc.c:390
ufs_mkdir(ffff80002a3462a0) at ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112
VOP_MKDIR(fffffd8072f678a0,ffff80002a346400,ffff80002a346430,ffff80002a346330) at VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394
domkdirat(ffff8000ffff3ca0,ffffff9c,71c0cf02fda0,1c0) at domkdirat+0x179 sys/kern/vfs_syscalls.c:3143
syscall(ffff80002a3465b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a3465b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71c0cf02fd60, count: -7

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/02 13:15 openbsd 8eafb9a57fa3 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore uvm_fault: ffs_nodealloccg
2026/03/29 18:42 openbsd 8c0bc7d7b019 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore uvm_fault: ffs_nodealloccg
2026/03/29 00:13 openbsd b39c1312a589 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore uvm_fault: ffs_nodealloccg
* Struck through repros no longer work on HEAD.