syzbot


panic: vref used where vget required (5)

Status: upstream: reported on 2025/12/20 21:36
Reported-by: syzbot+800aa2a739b75873b3c5@syzkaller.appspotmail.com
First crash: 121d, last: 35d
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd panic: vref used where vget required (4) 2 9 616d 740d 0/3 auto-obsoleted due to no activity on 2024/11/10 09:55
openbsd panic: vref used where vget required 2 1 2422d 2422d 0/3 auto-closed as invalid on 2019/12/01 17:58
openbsd panic: vref used where vget required (2) 2 2 2172d 2175d 0/3 auto-closed as invalid on 2020/08/08 03:01
openbsd panic: vref used where vget required (3) 2 1 1575d 1575d 0/3 auto-closed as invalid on 2022/03/27 19:54

Sample crash report:
panic: vref used where vget required
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*236156  66647      0           0  0x4000000    0K syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834b7b00) at panic+0x1e5 sys/kern/subr_prf.c:198
vref(fffffd806adef980) at vref+0x109 sys/kern/vfs_subr.c:708
namei(ffff80003c3e6558) at namei+0x555 sys/kern/vfs_lookup.c:221
dounlinkat(ffff8000fffe82c0,ffffff9c,200000001dc0,8) at dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1887
syscall(ffff80003c3e6730) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3e6730) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x215aa5bc9c0, 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{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: vref used where vget required
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834b7b00) at panic+0x1e5 sys/kern/subr_prf.c:198
vref(fffffd806adef980) at vref+0x109 sys/kern/vfs_subr.c:708
namei(ffff80003c3e6558) at namei+0x555 sys/kern/vfs_lookup.c:221
dounlinkat(ffff8000fffe82c0,ffffff9c,200000001dc0,8) at dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1887
syscall(ffff80003c3e6730) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3e6730) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x215aa5bc9c0, count: -7
ddb{0}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80003c3e63b0
rbx               0xffffffff8393de07    cpu_info_full_primary+0x2e07
rdx               0xffff8000015f5700
rcx               0xffff8000fffe82c0
rax               0xffffffff8393cff0    cpu_info_full_primary+0x1ff0
r8                 0x101010101010101
r9                0x8080808080808080
r10               0x2f84db9e71e81501
r11               0x3ff5dc2545823298
r12               0xffffffff8393dc08    cpu_info_full_primary+0x2c08
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff8282b645    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80003c3e63a0
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor) tid=236156 pid=66647 tcnt=3 stat=onproc
    flags process=0 proc=4000000<THREAD>
    runpri=79, usrpri=79, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff8000fffe94e8,0xffff8000fffe8d30
    process=0xffff8000fffef508 user=0xffff80003c3e1000, vmspace=0xfffffd806acb4410
    estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
  7229  518393  97784      0  2           0                syz-executor
  7229  357446  97784      0  3   0x4000080  fsleep        syz-executor
  4829  477959  48815      0  2           0                syz-executor
  4829   38531  48815      0  3   0x4000080  fsleep        syz-executor
 33507  419558  53984      0  2           0                syz-executor
 33507  138641  53984      0  3   0x4000080  fsleep        syz-executor
 35205  398544  80506      0  2           0                syz-executor
 35205  299449  80506      0  3   0x4000080  fsleep        syz-executor
 35205  477445  80506      0  3   0x4000080  fsleep        syz-executor
 53268   71390  90323      0  3        0x80  nanoslp       syz-executor
 53268  219130  90323      0  3   0x4000000  smrbar        syz-executor
 53268  417088  90323      0  3   0x4000080  fsleep        syz-executor
 53268  357649  90323      0  3   0x4000080  fsleep        syz-executor
 75482  373445   3788      0  2           0                syz-executor
 75482  458146   3788      0  3   0x4000080  fsleep        syz-executor
 66647  497958  24460      0  2           0                syz-executor
*66647  236156  24460      0  7   0x4000000                syz-executor
 66647  186490  24460      0  3   0x4000080  fsleep        syz-executor
 58131  377736  87888      0  2           0                syz-executor
 58131  194027  87888      0  3   0x4000080  fsleep        syz-executor
 58131   94587  87888      0  3   0x4000080  fsleep        syz-executor
 58131  174625  87888      0  3   0x4000080  fsleep        syz-executor
 62380  523391      0      0  3     0x14200  acct          acct
 87888   29490  12328      0  3        0x82  nanoslp       syz-executor
 90323  522739  12328      0  3        0x82  nanoslp       syz-executor
 24460  462491  12328      0  3        0x82  nanoslp       syz-executor
 48815  325697  12328      0  3        0x82  nanoslp       syz-executor
 80506  289344  12328      0  3        0x82  nanoslp       syz-executor
  3788  330874  12328      0  3        0x82  nanoslp       syz-executor
 53984  375704  12328      0  3        0x82  nanoslp       syz-executor
 97784  312298  12328      0  3        0x82  nanoslp       syz-executor
 12328  409343  26573      0  3        0x82  kqread        syz-executor
 26573   35439  79106      0  3    0x10008a  sigsusp       ksh
 79106  173165  26659      0  3        0x98  kqread        sshd-session
 26659  233041   4555      0  3        0x92  kqread        sshd-session
 32632  381608      1      0  3    0x100083  ttyopn        getty
  4555  521141      1      0  3        0x88  kqread        sshd
 57752   52629  89711     74  3   0x1100092  bpf           pflogd
 89711   70449      1      0  3        0x80  sbwait        pflogd
 29046  442660  79730     73  3   0x1100090  kqread        syslogd
 79730  385797      1      0  3    0x100082  sbwait        syslogd
 15973  234002      1      0  3    0x100080  kqread        resolvd
 78960  265588  76647     77  3    0x100092  kqread        dhcpleased
 55395   73572  76647     77  3    0x100092  kqread        dhcpleased
 76647  150138      1      0  3        0x80  kqread        dhcpleased
 95184   76105      0      0  3     0x14200  bored         smr
 79590  438432      0      0  2     0x14200                zerothread
 77756  410444      0      0  3     0x14200  aiodoned      aiodoned
  5140  150601      0      0  3     0x14200  syncer        update
 12539  271694      0      0  3     0x14200  cleaner       cleaner
 36201  501209      0      0  3     0x14200  reaper        reaper
 68393  184497      0      0  3     0x14200  pgdaemon      pagedaemon
 82351   80775      0      0  3     0x14200  bored         viomb
 43664  449001      0      0  3  0x40014200  acpi0         acpi0
 70499  141306      0      0  7  0x40014200                idle1
  2347  401751      0      0  3     0x14200  bored         softnet1
 81542   95963      0      0  3     0x14200  bored         softnet0
 36107  395332      0      0  3     0x14200  smrbar        systqmp
 91973  391716      0      0  3     0x14200  bored         systq
 18354   60544      0      0  3     0x14200  tmoslp        softclockmp
 94913  492050      0      0  3  0x40014200  tmoslp        softclock
 94629  365371      0      0  3  0x40014200                idle0
     1    8687      0      0  3        0x82  wait          init
     0       0     -1      0  3  0x10010200  scheduler     swapper
ddb{0}> show all locks
Process 66647 (syz-executor) thread 0xffff8000fffe82c0 (236156)
Process 36107 (systqmp) thread 0xffff8000ffffe298 (395332)
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11080  12109K   12392K 166960K     13354        0
            pcb    20     16K      17K 166960K       268        0
         rtable   246     10K      10K 166960K       519        0
             pf    36     17K      81K 166960K       156        0
         ifaddr    44      8K       8K 166960K        96        0
        ifgroup    57      2K       2K 166960K       149        0
         sysctl     4      1K       9K 166960K        13        0
       counters    76     37K      37K 166960K       180        0
       ioctlops     0      0K       8K 166960K      1747        0
            iov     0      0K      16K 166960K        82        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1511     95K      96K 166960K      2394        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K        14        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K        36        0
        dirhash    12      2K       2K 166960K        39        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    18     65K      93K 166960K      1070        0
          sigio     0      0K       0K 166960K         6        0
           proc    78    131K     164K 166960K       694        0
        subproc    72      4K       4K 166960K        90        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       112        0
       in_multi    99      7K       7K 166960K       148        0
    ether_multi     1      0K       0K 166960K         9        0
            mrt     1      0K       0K 166960K        28        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   127    572K     572K 166960K       127        0
           exec     0      0K       1K 166960K       566        0
   fusefs mount     1     32K      32K 166960K         1        0
     pfkey data     0      0K       0K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   248    159K     180K 166960K     11821        0
       UVM aobj    27     14K      14K 166960K        28        0
     pinsyscall    43     86K     104K 166960K      2349        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       1K 166960K        86        0
            NDP    13      0K       1K 166960K        71        0
           temp    77   9088K    9331K 166960K     54647        0
         kqueue    15     24K      34K 166960K       211        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      128    0      125     2     1     1     2     0     8    0
rtentry    176      153    0       50     6     0     6     6     0     8    0
unpcb      144      835    0      817    12     9     3     4     0     8    2
syncache   336       12    0       12     5     4     1     1     0     8    1
tcpqe       32        3    0        3     2     1     1     1     0     8    1
tcpcb      736      280    0      274     4     3     1     4     0     8    0
arp        136       26    0        7     1     0     1     1     0     8    0
inpcb      328     1303    0     1289    30    23     7     9     0     8    5
nd6        152       34    0        6     2     0     2     2     0     8    0
pkpcb       40       11    0       11     4     3     1     1     0     8    1
kcovpl      48       10    0        2     1     0     1     1     0     8    0
ppxss      1192      48    0       45     3     2     1     1     0     8    0
pffrag     232       11    0        5     1     0     1     1     0   482    0
pffrnode    88        9    0        3     1     0     1     1     0     8    0
pffrent     40       17    0       11     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       7    0        7     1     1     0     1     0     8    0
pfanchor   1288       1    0        1     1     1     0     1     0     8    0
pftag       88        1    0        1     1     1     0     1     0     8    0
pfstitem    24       63    0       25     1     0     1     1     0     8    0
pfstkey    128       63    0       25     2     0     2     2     0     8    0
pfstate    448       63    0       25     5     0     5     5     0     8    0
pfrule     1360      25    0       20     2     1     1     2     0     8    0
rttmr      136        2    0        2     2     2     0     1     0     8    0
art_heap8  4096       2    0        0     2     0     2     2     0     8    0
art_heap4  256      648    0      219    35     8    27    29     0     8    0
art_table   40      650    0      219     5     0     5     5     0     8    0
art_node    32      152    0       59     1     0     1     1     0     8    0
sysvmsgpl   40        3    0        1     1     0     1     1     0     8    0
semapl     112       33    0       23     1     0     1     1     0     8    0
shmpl      112       18    0        0     1     0     1     1     0     8    0
dirhash    1024      36    0       19     3     0     3     3     0     8    0
dino2pl    256     3395    0     1932    93     0    93    93     0     8    0
ffsino     296     3395    0     1932   114     0   114   114     0     8    0
nchpl      144     4912    0     3202    64     0    64    64     0     8    0
rtmask      32       10    0       10     3     3     0     1     0     8    0
vnodes     216     4130    0        0   230     0   230   230     0     8    0
vnodes: pool(0xffffffff83a6e570:vnodes): page inconsistency: page 0x0; at page head addr 0xfffffd806adeff90 (p 0xfffffd806adef000)
namei      1024   16309    0    16308     2     1     1     2     0     8    0
percpumem   16      105    0       52     1     0     1     1     0     8    0
vcpupl     3968       7    0        1     1     0     1     1     0     8    0
vmpool     848        7    0        1     1     0     1     1     0     8    0
pfiaddrpl  120        2    0        2     1     1     0     1     0     8    0
kstatmem   264      102    0       74     5     3     2     3     0     8    0
acpiwqpl    32        1    0        1     1     0     1     1     1     8    1
scsiplug    72        8    0        8     3     2     1     1     0     8    1
scxspl     216    19761    0    19761    13    11     2     8     1     8    2
plimitpl   152      247    0      227     1     0     1     1     0     8    0
sigapl     424     1419    0     1370     8     2     6     8     0     8    0
knotepl    120      494    0        0    15     0    15    15     0     8    0
kqueuepl   224      387    0      374     4     1     3     3     0     8    2
pipepl     344      217    0      190     3     0     3     3     0     8    0
fdescpl    528     1380    0     1348     3     0     3     3     0     8    0
filepl     160     8672    0     8449    28    13    15    18     0     8    4
lockfpl    104      618    0      616     3     2     1     3     0     8    0
lockfspl    48      282    0      280     2     1     1     2     0     8    0
sessionpl  144       33    0       24     1     0     1     1     0     8    0
pgrppl      48       52    0       35     1     0     1     1     0     8    0
ucredpl    104     1252    0     1239     1     0     1     1     0     8    0
zombiepl   144     1779    0     1779     1     0     1     1     0     8    1
processpl  1232    1419    0     1370     6     2     4     6     0     8    0
procpl     664     2989    0     2926     7     1     6     7     0     8    0
sosppl     176        9    0        9     3     3     0     1     0     8    0
sockpl     752     2311    0     2276    34    23    11    13     0     8    6
mcl64k     65536      6    0        0     1     0     1     1     0     8    0
mcl16k     16384      1    0        0     1     0     1     1     0     8    0
mcl12k     12288      1    0        0     1     0     1     1     0     8    0
mcl9k      9216       1    0        0     1     0     1     1     0     8    0
mcl8k      8192       2    0        0     1     0     1     1     0     8    0
mcl4k      4096     130    0        0    16     0    16    16     0     8    0
mcl2k      2048      42    0        0     5     0     5     5     0     8    0
mtagpl      96       12    0        0     1     0     1     1     0     8    0
mbufpl     256      208    0        0    13     0    13    13     0     8    0
bufpl      280     6615    0      485   439     0   439   439     0     8    0
anonpl      32    10384    0        0    84     0    84    84     0   246    0
amapchunkpl 152   39644    0    39117    59    25    34    34     0   158   11
amappl16   200     4138    0     4100    35    30     5    18     0     8    1
amappl15   192        6    0        6     1     1     0     1     0     8    0
amappl14   184      453    0      452     1     0     1     1     0     8    0
amappl13   176      152    0      140     1     0     1     1     0     8    0
amappl12   168     1650    0     1619     2     0     2     2     0     8    0
amappl11   160        5    0        5     1     1     0     1     0     8    0
amappl10   152       66    0       52     1     0     1     1     0     8    0
amappl9    144      310    0      310     1     1     0     1     0     8    0
amappl8    136      114    0      112     1     0     1     1     0     8    0
amappl7    128      169    0      156     1     0     1     1     0     8    0
amappl6    120      176    0      171     1     0     1     1     0     8    0
amappl5    112      117    0      106     1     0     1     1     0     8    0
amappl4    104      337    0      316     1     0     1     1     0     8    0
amappl3     96     6901    0     6795     3     0     3     3     0     8    0
amappl2     88     1612    0     1532     3     0     3     3     0     8    0
amappl1     80    17589    0    16980    26     9    17    17     0     8    3
amappl      88    10817    0    10641     6     1     5     5     0    92    0
uvmvnodes   80      140    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        7    0        7     2     2     0     1     0     8    0
dma128     128      255    0      255     3     2     1     1     0     8    1
dma64       64        6    0        6     1     1     0     1     0     8    0
dma32       32        8    0        8     2     1     1     1     0     8    1
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72       27    0        1     1     0     1     1     0     8    0
uaddrrnd    24     1380    0     1348     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1380    0     1348     1     0     1     1     0     8    0
vmmpekpl   168    13887    0    13840     3     0     3     3     0     8    0
vmmpepl    168   100015    0    98016   133    33   100   108     0   357    3
vmsppl     488     1379    0     1348     9     4     5     5     0     8    0
rwobjpl     80    30290    0    29162    35     7    28    31     0     8    0
pdppl      4096    2781    0     2704   145    65    80    85     0     8    3
pvpl        32    18632    0        0   150     0   150   150     0   265    0
pmappl     256     1386    0     1349     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      340    0       85     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(ffffffff834b7b00) at panic+0x1e5 sys/kern/subr_prf.c:198
vref(fffffd806adef980) at vref+0x109 sys/kern/vfs_subr.c:708
namei(ffff80003c3e6558) at namei+0x555 sys/kern/vfs_lookup.c:221
dounlinkat(ffff8000fffe82c0,ffffff9c,200000001dc0,8) at dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1887
syscall(ffff80003c3e6730) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3e6730) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x215aa5bc9c0, count: -7
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
x86_ipi_db(ffff8000299bdff0) 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
acpicpu_idle() at acpicpu_idle+0x457 sys/dev/acpi/acpicpu_x86.c:1224
sched_idle(ffff8000299bdff0) at sched_idle+0x391 sys/kern/kern_sched.c:191
end trace frame: 0x0, count: 10
ddb{1}> trace
x86_ipi_db(ffff8000299bdff0) 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
acpicpu_idle() at acpicpu_idle+0x457 sys/dev/acpi/acpicpu_x86.c:1224
sched_idle(ffff8000299bdff0) at sched_idle+0x391 sys/kern/kern_sched.c:191
end trace frame: 0x0, count: -5

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/16 17:02 openbsd 15ef65f2835f 64e21424 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore panic: vref used where vget required
2026/01/01 06:26 openbsd 6a1433bd6d39 2733a373 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore panic: vref used where vget required
2025/12/20 21:35 openbsd df8f251ef5f9 e14dbeb9 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore panic: vref used where vget required
* Struck through repros no longer work on HEAD.