uvm_fault: device_lookup

Status: upstream: reported on 2026/07/25 03:44
Reported-by: syzbot+2cbc1aa46b0f2ece7b02@syzkaller.appspotmail.com
First crash: 11d, last: 11d

Sample crash report:
uvm_fault(0xffffef807f230000, 0x798e267b, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      device_lookup+0x7b:     movl    0x40(%rax),%r15d
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*  3958  49582      0         0x2          0    0  syz-executor
device_lookup(ffffffff83920d10,0) at device_lookup+0x7b sys/kern/subr_autoconf.c:954
disk_lookup(ffffffff83920d10,0) at disk_lookup+0x3b sys/kern/subr_disk.c:-1
sdstrategy(ffffef806dcbecc8) at sdstrategy+0x53 sys/scsi/sd.c:530
spec_strategy(ffff80002a7d0ce8) at spec_strategy+0x42 sys/kern/spec_vnops.c:448
VOP_STRATEGY(ffffef8009871948,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
ufs_strategy(ffff80002a7d0d88) at ufs_strategy+0x1f0 sys/ufs/ufs/ufs_vnops.c:-1
VOP_STRATEGY(ffffef806e2f0b28,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
bwrite(ffffef806dcbecc8) at bwrite+0x2f5 sys/kern/vfs_bio.c:616
ufs_dirremove(ffffef806e2f0b28,ffffef806f084400,800c,1) at ufs_dirremove+0x28d sys/ufs/ufs/ufs_lookup.c:919
ufs_rmdir(ffff80002a7d0ef0) at ufs_rmdir+0x238 sys/ufs/ufs/ufs_vnops.c:1248
VOP_RMDIR(ffffef806e2f0b28,ffffef8062176a80,ffff80002a7d0fc8) at VOP_RMDIR+0x192 sys/kern/vfs_vops.c:413
dounlinkat(ffff80002a7662a8,ffffff9c,7f5cf1392c90,8) at dounlinkat+0x2e0 sys/kern/vfs_syscalls.c:1840
syscall(ffff80002a7d1130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7d1130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f5cf1392c80, count: 1
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> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffef807f230000, 0x798e267b, 0, 1) -> e
ddb> show kasan
No such command
ddb> trace
device_lookup(ffffffff83920d10,0) at device_lookup+0x7b sys/kern/subr_autoconf.c:954
disk_lookup(ffffffff83920d10,0) at disk_lookup+0x3b sys/kern/subr_disk.c:-1
sdstrategy(ffffef806dcbecc8) at sdstrategy+0x53 sys/scsi/sd.c:530
spec_strategy(ffff80002a7d0ce8) at spec_strategy+0x42 sys/kern/spec_vnops.c:448
VOP_STRATEGY(ffffef8009871948,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
ufs_strategy(ffff80002a7d0d88) at ufs_strategy+0x1f0 sys/ufs/ufs/ufs_vnops.c:-1
VOP_STRATEGY(ffffef806e2f0b28,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
bwrite(ffffef806dcbecc8) at bwrite+0x2f5 sys/kern/vfs_bio.c:616
ufs_dirremove(ffffef806e2f0b28,ffffef806f084400,800c,1) at ufs_dirremove+0x28d sys/ufs/ufs/ufs_lookup.c:919
ufs_rmdir(ffff80002a7d0ef0) at ufs_rmdir+0x238 sys/ufs/ufs/ufs_vnops.c:1248
VOP_RMDIR(ffffef806e2f0b28,ffffef8062176a80,ffff80002a7d0fc8) at VOP_RMDIR+0x192 sys/kern/vfs_vops.c:413
dounlinkat(ffff80002a7662a8,ffffff9c,7f5cf1392c90,8) at dounlinkat+0x2e0 sys/kern/vfs_syscalls.c:1840
syscall(ffff80002a7d1130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7d1130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f5cf1392c80, count: -14
ddb> show registers
rdi                              0x2
rsi                                0
rbp               0xffff80002a7d0c20
rbx               0xffffef807b9b0600
rdx                                0
rcx                                0
rax                       0x798e263b
r8                0xffffffffffffffff
r9                               0x1
r10               0xf4c26ae726c5d522
r11               0x4930f16e10149abf
r12                              0x2
r13                                0
r14                       0x798e263b
r15               0xffffffff83920d10    sd_cd
rip               0xffffffff8263f36b    device_lookup+0x7b
cs                               0x8
rflags                       0x10202    __ALIGN_SIZE+0xf202
rsp               0xffff80002a7d0bf0
ss                              0x10
device_lookup+0x7b:     movl    0x40(%rax),%r15d
ddb> show proc
PROC (syz-executor) tid=3958 pid=49582 tcnt=1 stat=onproc
    flags process=2<EXEC> proc=0
    runpri=50, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a766010,0xffff80002a767a10
    process=0xffff80002a79c010 user=0xffff80002a7cc000, vmspace=0xffffef807f230000
    estcpu=36, cpticks=3, pctcpu=0.0, user=0, sys=3, intr=0
ddb> ps
   PID     TID   PPID   UID  S      PRLAGS     PFLAGS WAIT      COMMAND
 11386  228466  47738     0  2           0          0           syz-executor
 11386  454276  47738     0  3           0  0x4000080 fsleep    syz-executor
 38721   96864  11732     0  2           0          0           syz-executor
 38721  108111  11732     0  3           0  0x4000080 fsleep    syz-executor
 72474  213142  86292     0  2           0          0           syz-executor
 72474  130541  86292     0  3           0  0x4000080 fsleep    syz-executor
 44421  147616  94376     0  2           0          0           syz-executor
 44421  509918  94376     0  3           0  0x4000080 fsleep    syz-executor
 79737  252436   9420     0  2           0          0           syz-executor
 79737  447361   9420     0  3           0  0x4000080 fsleep    syz-executor
 79737    8552   9420     0  3           0  0x4000080 fsleep    syz-executor
 79737  251378   9420     0  3           0  0x4000080 fsleep    syz-executor
 89237  411361  58192     0  2           0          0           syz-executor
 89237   41694  58192     0  3           0  0x4000080 fsleep    syz-executor
 89237  401663  58192     0  2           0  0x4000000           syz-executor
 52664  498709  71757     0  2         0x2          0           syz-executor
 86292  488104  71757     0  2         0x2      0xc80           syz-executor
  9420   20657  71757     0  2         0x2      0xc80           syz-executor
 47738   80080  71757     0  3         0x2       0x80 nanoslp   syz-executor
 94376  346783  71757     0  2         0x2      0xc80           syz-executor
 11732  295231  71757     0  2         0x2      0xc80           syz-executor
 58192  309647  71757     0  2         0x2      0xc80           syz-executor
*49582    3958  71757     0  7         0x2          0           syz-executor
 71757  242951  18445     0  2         0x2          0           syz-executor
 18445   92835  10832     0  3    0x100002       0x88 sigsusp   ksh
 10832  318100  30299     0  3        0x10       0x88 kqread    sshd-session
 30299  440627  65718     0  3        0x12       0x80 kqread    sshd-session
  4891  126530      1     0  3    0x100003       0x80 ttyin     getty
 65718  170754      1     0  3           0       0x88 kqread    sshd
 41534  396871  61805    73  3   0x1100010       0x80 kqread    syslogd
 61805  298445      1     0  3    0x100002       0x80 sbwait    syslogd
 66458  168600      1     0  3    0x100000       0x80 kqread    resolvd
 88383  288228  86912    77  3    0x100012       0x80 kqread    dhcpleased
 74006  361894  86912    77  3    0x100012       0x80 kqread    dhcpleased
 86912  347443      1     0  3           0       0x80 kqread    dhcpleased
 87495  243005      0     0  3     0x14000      0x200 bored     smr
 42592  426686      0     0  2     0x14000      0x200           zerothread
 12867   54869      0     0  3     0x14000      0x200 aiodoned  aiodoned
 67338  266951      0     0  3     0x14000      0x200 syncer    update
  2743  339382      0     0  3     0x14000      0x200 cleaner   cleaner
 96317   26285      0     0  3     0x14000      0x200 reaper    reaper
 78987   84631      0     0  3     0x14000      0x200 pgdaemon  pagedaemon
  9853  449597      0     0  3     0x14000      0x200 bored     viomb
 86465  185614      0     0  3     0x14000 0x40000200 acpi0     acpi0
 64024  241106      0     0  3     0x14000      0x200 bored     softnet0
 91803   42679      0     0  3     0x14000      0x200 bored     systqmp
 42487   13393      0     0  3     0x14000      0x200 bored     systq
 60644  247666      0     0  3     0x14000 0x40000200 tmoslp    softclock
 37796  493355      0     0  3     0x14000 0x40000200           idle0
     1  237749      0     0  3         0x2       0x80 wait      init
     0       0     -1     0  3     0x10000      0x200 scheduler swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11042  12183K   12251K 166960K     12374        0
            pcb    17     12K      12K 166960K        47        0
         rtable   216      6K       9K 166960K       560        0
             pf    29     12K      17K 166960K        60        0
         ifaddr    38      6K       7K 166960K        71        0
        ifgroup    46      2K       2K 166960K        76        0
         sysctl     2      1K       9K 166960K         7        0
       counters    32     17K      17K 166960K        40        0
       ioctlops     0      0K       4K 166960K        68        0
            iov     0      0K      16K 166960K        13        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1297     82K      82K 166960K      1535        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       9K 166960K        10        0
         VM map     2      1K       1K 166960K         2        0
            sem    11      0K       0K 166960K        80        0
        dirhash    12      2K       2K 166960K        15        0
           ACPI  1734    201K     291K 166960K     11964        0
      file desc    16     57K     236K 166960K       432        0
          sigio     0      0K       0K 166960K         2        0
           proc    60     59K      83K 166960K       690        0
        subproc    64      4K       4K 166960K       127        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        16        0
       in_multi    88      6K       7K 166960K       165        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K        16        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    73    334K     334K 166960K        73        0
           exec     0      0K       1K 166960K       472        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   212    158K     173K 166960K      4971        0
       UVM aobj     9      2K       2K 166960K        10        0
     pinsyscall    37     74K      96K 166960K      1685        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        10        0
            NDP    10      0K       2K 166960K        46        0
           temp    33   9110K    9118K 166960K     14558        0
         kqueue    14     22K      26K 166960K        60        0
      SYN cache     2     16K      16K 166960K         2        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
rtpcb      120       59    0       56     1     0     1     1     0     8    0
rtentry    136      179    0       80     4     0     4     4     0     8    0
unpcb      144      136    0      119     1     0     1     1     0     8    0
syncache   336        7    0        7     2     1     1     1     0     8    1
tcpcb      736       57    0       52     1     0     1     1     0     8    0
arp         96       30    0       14     1     0     1     1     0     8    0
ipq         40        2    0        0     1     0     1     1     0     8    0
ipqe        40        2    0        0     1     0     1     1     0     8    0
inpcb      328      286    0      276     7     0     7     7     0     8    5
ip6q        72        1    0        0     1     0     1     1     0     8    0
ip6af       40        1    0        0     1     0     1     1     0     8    0
nd6        112       43    0       22     1     0     1     1     0     8    0
kcovpl      48       14    0        7     1     0     1     1     0     8    0
ppxss      1072       1    0        1     1     0     1     1     0     8    1
pfrktable  1344       7    0        7     1     0     1     1     0     8    1
pfstlim    224        1    0        0     1     0     1     1     0     8    0
pfanchor   1288       2    0        2     1     0     1     1     0     8    1
pftag       88        1    0        1     1     0     1     1     0     8    1
pfrule     1360       2    0        2     1     0     1     1     0     8    1
rttmr      136        1    0        1     1     0     1     1     0     8    1
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      722    0      310    29     0    29    29     0     8    1
art_table   40      723    0      310     5     0     5     5     0     8    0
art_node    32      179    0       89     1     0     1     1     0     8    0
sysvmsgpl   40        5    0        3     1     0     1     1     0     8    0
semapl      72       78    0       69     1     0     1     1     0     8    0
shmpl      112        7    0        1     1     0     1     1     0     8    0
dirhash    1024      19    0        2     3     0     3     3     0     8    0
dino2pl    256     1901    0      431    92     0    92    92     0     8    0
ffsino     256     1901    0      431    92     0    92    92     0     8    0
nchpl      144     2382    0      670    64     0    64    64     0     8    0
vnodes     216     2108    0        0   118     0   118   118     0     8    0
namei      1024    7839    0     7839     3     2     1     2     0     8    1
pfiaddrpl  120        2    0        2     1     0     1     1     0     8    1
kstatmem   264       37    0       16     2     0     2     2     0     8    0
scxspl     216     7824    0     7824     4     2     2     3     1     8    2
plimitpl   152       57    0       41     1     0     1     1     0     8    0
sigapl     424      703    0      662     6     1     5     6     0     8    0
knotepl    120     9709    0     9413    11     0    11    11     0     8    2
kqueuepl   184       67    0       57     1     0     1     1     0     8    0
pipepl     304      163    0      136     3     0     3     3     0     8    0
fdescpl    448      690    0      662     5     1     4     5     0     8    0
filepl     120     2799    0     2561     9     0     9     9     0     8    1
lockfpl    104       71    0       68     1     0     1     1     0     8    0
lockfspl    48       34    0       31     1     0     1     1     0     8    0
sessionpl  144       35    0       27     1     0     1     1     0     8    0
pgrppl      48       63    0       47     1     0     1     1     0     8    0
ucredpl    104      312    0      301     1     0     1     1     0     8    0
zombiepl   144      662    0      662     2     1     1     1     0     8    1
processpl  1152     703    0      662     4     0     4     4     0     8    0
procpl     664      975    0      925     5     0     5     5     0     8    0
sockpl     552      491    0      461     8     0     8     8     0     8    5
mcl64k     65536     10    0       10     1     0     1     1     0     8    1
mcl16k     16384      7    0        7     2     1     1     1     0     8    1
mcl12k     12288      1    0        1     1     0     1     1     0     8    1
mcl8k      8192       9    0        7     1     0     1     1     0     8    0
mcl4k      4096    2797    0     2748    13     5     8    12     0     8    1
mcl2k      2048     407    0      405     6     1     5     5     0     8    4
mextrefs    64      177    0      176     2     1     1     1     0     8    0
mtagpl      96        4    0        4     1     1     0     1     0     8    0
mbufpl     256     6745    0     6584    15     0    15    15     0     8    2
bufpl      272     2832    0      102   182     0   182   182     0     8    0
anonpl      24    89287    0    78037    69     0    69    69     0   187    0
amapchunkpl 152   14490    0    14018    29     0    29    29     0   158    9
amappl16   200     1027    0      525    30     3    27    27     0     8    0
amappl15   192       33    0       32     1     0     1     1     0     8    0
amappl14   184      480    0      479     1     0     1     1     0     8    0
amappl13   176      124    0      114     1     0     1     1     0     8    0
amappl12   168      986    0      959     2     0     2     2     0     8    0
amappl11   160        4    0        4     1     1     0     1     0     8    0
amappl10   152       54    0       44     1     0     1     1     0     8    0
amappl9    144      278    0      278     1     1     0     1     0     8    0
amappl8    136      114    0      113     1     0     1     1     0     8    0
amappl7    128      175    0      164     1     0     1     1     0     8    0
amappl6    120      220    0      218     1     0     1     1     0     8    0
amappl5    112      118    0      109     1     0     1     1     0     8    0
amappl4    104      277    0      262     1     0     1     1     0     8    0
amappl3     96     2880    0     2778     3     0     3     3     0     8    0
amappl2     88      573    0      520     2     0     2     2     0     8    0
amappl1     80    11650    0    11112    14     1    13    14     0     8    1
amappl      88     4131    0     3982     4     0     4     4     0    92    0
uvmvnodes   80      101    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
dma512     512        1    0        1     1     0     1     1     0     8    1
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      690    0      662     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      690    0      662     1     0     1     1     0     8    0
vmmpekpl   168     7173    0     7126     3     0     3     3     0     8    0
vmmpepl    168    51257    0    49075   101     3    98    98     0   357    0
vmsppl     368      689    0      662     4     1     3     4     0     8    0
rwobjpl     40    16357    0    14943    15     0    15    15     0     8    0
pdppl      4096    1386    0     1324   116    50    66    80     0     8    4
pvpl        32   289567    0   272909   140     3   137   137     0   265    0
pmappl     216      689    0      662     3     0     3     3     0     8    1
extentpl    40       46    0       28     1     0     1     1     0     8    0
phpool     112      573    0       64    15     0    15    15     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
device_lookup(ffffffff83920d10,0) at device_lookup+0x7b sys/kern/subr_autoconf.c:954
disk_lookup(ffffffff83920d10,0) at disk_lookup+0x3b sys/kern/subr_disk.c:-1
sdstrategy(ffffef806dcbecc8) at sdstrategy+0x53 sys/scsi/sd.c:530
spec_strategy(ffff80002a7d0ce8) at spec_strategy+0x42 sys/kern/spec_vnops.c:448
VOP_STRATEGY(ffffef8009871948,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
ufs_strategy(ffff80002a7d0d88) at ufs_strategy+0x1f0 sys/ufs/ufs/ufs_vnops.c:-1
VOP_STRATEGY(ffffef806e2f0b28,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
bwrite(ffffef806dcbecc8) at bwrite+0x2f5 sys/kern/vfs_bio.c:616
ufs_dirremove(ffffef806e2f0b28,ffffef806f084400,800c,1) at ufs_dirremove+0x28d sys/ufs/ufs/ufs_lookup.c:919
ufs_rmdir(ffff80002a7d0ef0) at ufs_rmdir+0x238 sys/ufs/ufs/ufs_vnops.c:1248
VOP_RMDIR(ffffef806e2f0b28,ffffef8062176a80,ffff80002a7d0fc8) at VOP_RMDIR+0x192 sys/kern/vfs_vops.c:413
dounlinkat(ffff80002a7662a8,ffffff9c,7f5cf1392c90,8) at dounlinkat+0x2e0 sys/kern/vfs_syscalls.c:1840
syscall(ffff80002a7d1130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7d1130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f5cf1392c80, count: -14
ddb> machine ddbcpu 1
No such command
ddb> trace
device_lookup(ffffffff83920d10,0) at device_lookup+0x7b sys/kern/subr_autoconf.c:954
disk_lookup(ffffffff83920d10,0) at disk_lookup+0x3b sys/kern/subr_disk.c:-1
sdstrategy(ffffef806dcbecc8) at sdstrategy+0x53 sys/scsi/sd.c:530
spec_strategy(ffff80002a7d0ce8) at spec_strategy+0x42 sys/kern/spec_vnops.c:448
VOP_STRATEGY(ffffef8009871948,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
ufs_strategy(ffff80002a7d0d88) at ufs_strategy+0x1f0 sys/ufs/ufs/ufs_vnops.c:-1
VOP_STRATEGY(ffffef806e2f0b28,ffffef806dcbecc8) at VOP_STRATEGY+0x65 sys/kern/vfs_vops.c:636
bwrite(ffffef806dcbecc8) at bwrite+0x2f5 sys/kern/vfs_bio.c:616
ufs_dirremove(ffffef806e2f0b28,ffffef806f084400,800c,1) at ufs_dirremove+0x28d sys/ufs/ufs/ufs_lookup.c:919
ufs_rmdir(ffff80002a7d0ef0) at ufs_rmdir+0x238 sys/ufs/ufs/ufs_vnops.c:1248
VOP_RMDIR(ffffef806e2f0b28,ffffef8062176a80,ffff80002a7d0fc8) at VOP_RMDIR+0x192 sys/kern/vfs_vops.c:413
dounlinkat(ffff80002a7662a8,ffffff9c,7f5cf1392c90,8) at dounlinkat+0x2e0 sys/kern/vfs_syscalls.c:1840
syscall(ffff80002a7d1130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7d1130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f5cf1392c80, count: -14

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/25 03:43 openbsd f3d8a5574675 492bab15 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: device_lookup
* Struck through repros no longer work on HEAD.