uvm_fault: wsmouseopen

Status: upstream: reported on 2026/09/12 14:35
Reported-by: syzbot+4a4ad3aecca49a413769@syzkaller.appspotmail.com
First crash: 7d17h, last: 7d17h

Sample crash report:
uvm_fault(0xffffffff839bd678, 0xffff80000000424c, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      wsmouseopen+0x78:       movzbl  0x24c(%r14),%r12d
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*116858  10130      0           0  0x4000000    0  syz-executor
wsmouseopen(4400,1,2000,ffff80002a7d27f0) at wsmouseopen+0x78 sys/dev/wscons/wsmouse.c:309
spec_open(ffff80002a7f5148) at spec_open+0x2d6 sys/kern/spec_vnops.c:150
VOP_OPEN(fffffd006fb63878,1,fffffd0007ffd618,ffff80002a7d27f0) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138
vn_open(ffff80002a7f53a0,1,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff80002a7d27f0,ffffff9c,200000000040,0,0,0,2529779ad1f2008a) at doopenat+0x352 sys/kern/vfs_syscalls.c:1163
sys_openat(ffff80002a7d27f0,ffff80002a7f5640,ffff80002a7f5590) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1102
syscall(ffff80002a7f5640) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7f5640) at syscall+0x962 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xdbeb5831a40, count: 7
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.
ddb> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffffff839bd678, 0xffff80000000424c, 0, 1) -> e
ddb> show kasan
No such command
ddb> trace
wsmouseopen(4400,1,2000,ffff80002a7d27f0) at wsmouseopen+0x78 sys/dev/wscons/wsmouse.c:309
spec_open(ffff80002a7f5148) at spec_open+0x2d6 sys/kern/spec_vnops.c:150
VOP_OPEN(fffffd006fb63878,1,fffffd0007ffd618,ffff80002a7d27f0) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138
vn_open(ffff80002a7f53a0,1,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff80002a7d27f0,ffffff9c,200000000040,0,0,0,2529779ad1f2008a) at doopenat+0x352 sys/kern/vfs_syscalls.c:1163
sys_openat(ffff80002a7d27f0,ffff80002a7f5640,ffff80002a7f5590) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1102
syscall(ffff80002a7f5640) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7f5640) at syscall+0x962 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xdbeb5831a40, count: -8
ddb> show registers
rdi                                0
rsi                              0x2
rbp               0xffff80002a7f50c0
rbx               0xffff80002a7d27f0
rdx                                0
rcx                                0
rax               0xffff80000002e310
r8                             0x100
r9                0xfffffd0007ffd618
r10               0x87cb57dd2199df3e
r11                0x6968cd6e1322e9c
r12                              0x2
r13                                0
r14               0xffff800000004000
r15                              0x1
rip               0xffffffff82ff8dd8    wsmouseopen+0x78
cs                               0x8
rflags                       0x10286    __ALIGN_SIZE+0xf286
rsp               0xffff80002a7f5080
ss                              0x10
wsmouseopen+0x78:       movzbl  0x24c(%r14),%r12d
ddb> show proc
PROC (syz-executor) tid=116858 pid=10130 tcnt=2 stat=onproc
    flags process=0 proc=4000000<THREAD>
    runpri=32, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a7d2fb8,0xffff80002a7d3260
    process=0xffff800045ff9b18 user=0xffff80002a7f0000, vmspace=0xfffffd006d1bb8b0
    estcpu=0, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID   UID  S      PRLAGS     PFLAGS WAIT      COMMAND
 27693  369154  46286     0  2           0          0           syz-executor
 32733  370041  45274     0  2           0          0           syz-executor
 34464   31699  73025     0  2           0          0           syz-executor
 31410  458320  31430     0  2           0          0           syz-executor
 31410  201221  31430     0  3           0  0x4000080 fsleep    syz-executor
 31410  522568  31430     0  3           0  0x4000080 fsleep    syz-executor
 87160   83424  88944     0  2           0          0           syz-executor
 10130  480716  79965     0  2           0          0           syz-executor
*10130  116858  79965     0  7           0  0x4000000           syz-executor
 28445   26915  22678     0  2         0x2          0           syz-executor
 31430   70511  22678     0  2         0x2      0xc80           syz-executor
 77610  123771  22678     0  3         0x2       0x80 piperd    syz-executor
 79965  479823  22678     0  2         0x2      0xc80           syz-executor
 45274  445438  22678     0  3         0x2       0x80 nanoslp   syz-executor
 46286  251944  22678     0  3         0x2       0x80 nanoslp   syz-executor
 73025  177475  22678     0  2         0x2      0xc80           syz-executor
 88944  162816  22678     0  2         0x2      0xc80           syz-executor
 22678  482419   4501     0  2         0x2          0           syz-executor
  4501  429278   8221     0  3    0x100002       0x88 sigsusp   ksh
  8221  203734  21738     0  3        0x10       0x88 kqread    sshd-session
 21738  444063  59816     0  3        0x12       0x80 kqread    sshd-session
 89702  188469      1     0  3    0x100003       0x80 ttyin     getty
 59816   50026      1     0  3           0       0x88 kqread    sshd
 94566  165571  10087    73  3   0x1100010       0x80 kqread    syslogd
 10087  384792      1     0  3    0x100002       0x80 sbwait    syslogd
 17520  495619      1     0  3    0x100000       0x80 kqread    resolvd
 43879  251061  97743    77  3    0x100012       0x80 kqread    dhcpleased
 85946  436289  97743    77  3    0x100012       0x80 kqread    dhcpleased
 97743  249864      1     0  3           0       0x80 kqread    dhcpleased
 39907  490701      0     0  3     0x14000      0x200 bored     smr
 40462  319830      0     0  2     0x14000      0x200           zerothread
 74689   76288      0     0  3     0x14000      0x200 aiodoned  aiodoned
  2055  515521      0     0  3     0x14000      0x200 syncer    update
 27160  161943      0     0  3     0x14000      0x200 cleaner   cleaner
 14665  333014      0     0  3     0x14000      0x200 reaper    reaper
 35764   92775      0     0  3     0x14000      0x200 pgdaemon  pagedaemon
 97205    7855      0     0  3     0x14000      0x200 bored     viomb
 54101   55010      0     0  3     0x14000 0x40000200 acpi0     acpi0
 45811    5187      0     0  2     0x14000      0x200           softnet0
 83130  323049      0     0  3     0x14000      0x200 smrbar    systqmp
 28233  390054      0     0  3     0x14000      0x200 bored     systq
 64221   31563      0     0  3     0x14000 0x40000200 tmoslp    softclock
 87553   72331      0     0  3     0x14000 0x40000200           idle0
     1   76615      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 11033  12101K   12175K 166960K     12191        0
            pcb    17     12K      12K 166960K        25        0
         rtable   216      6K       8K 166960K       639        0
             pf    28     12K      16K 166960K        68        0
         ifaddr    38      6K       7K 166960K        84        0
        ifgroup    46      2K       2K 166960K        90        0
         sysctl     1      1K       9K 166960K         5        0
       counters    32     17K      17K 166960K        44        0
       ioctlops     0      0K       4K 166960K        45        0
            iov     0      0K       1K 166960K         3        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1293     81K      81K 166960K      1482        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K         7        0
         VM map     2      1K       1K 166960K         2        0
            sem     5      0K       0K 166960K         7        0
        dirhash    12      2K       2K 166960K        12        0
           ACPI  1734    201K     291K 166960K     11964        0
      file desc    16     57K      93K 166960K       331        0
          sigio     0      0K       0K 166960K         1        0
           proc    59     59K      91K 166960K       755        0
        subproc    67      4K       4K 166960K       157        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K         5        0
       in_multi    88      5K       6K 166960K       198        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K         3        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    85    387K     387K 166960K        85        0
           exec     0      0K       1K 166960K       485        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   186    158K     166K 166960K      4113        0
       UVM aobj     4      2K       2K 166960K         4        0
     pinsyscall    37     74K      94K 166960K      1662        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K         1        0
            NDP    14      0K       2K 166960K        56        0
           temp    33   9106K    9170K 166960K      4820        0
         kqueue    14     22K      22K 166960K        33        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       56    0       53     1     0     1     1     0     8    0
rtentry    136      210    0      111     4     0     4     4     0     8    0
unpcb      144       56    0       41     1     0     1     1     0     8    0
syncache   336        6    0        6     1     0     1     1     0     8    1
tcpcb      736       26    0       22     1     0     1     1     0     8    0
arp         96       36    0       20     1     0     1     1     0     8    0
inpcb      328      134    0      127     2     0     2     2     0     8    1
nd6        112       51    0       30     1     0     1     1     0     8    0
kcovpl      48       17    0       10     1     0     1     1     0     8    0
ppxss      1072       2    0        2     1     0     1     1     0     8    1
pfrktable  1344       7    0        7     1     0     1     1     0     8    1
pfanchor   1288       3    0        3     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
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      851    0      396    31     0    31    31     0     8    2
art_table   40      852    0      396     6     0     6     6     0     8    0
art_node    32      210    0      119     1     0     1     1     0     8    0
sysvmsgpl   40        1    0        1     1     0     1     1     0     8    1
semapl      72        5    0        2     1     0     1     1     0     8    0
shmpl      112        1    0        0     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1673    0      192    93     0    93    93     0     8    0
ffsino     256     1673    0      192    93     0    93    93     0     8    0
nchpl      144     1947    0      222    65     0    65    65     0     8    0
vnodes     216     1859    0        0   104     0   104   104     0     8    0
namei      1024    7650    0     7650     2     0     2     2     0     8    2
pfiaddrpl  120        2    0        2     1     0     1     1     0     8    1
kstatmem   264       45    0       24     2     0     2     2     0     8    0
scxspl     216     6521    0     6521     3     0     3     3     1     8    3
plimitpl   152      304    0      288     1     0     1     1     0     8    0
sigapl     424      605    0      564     6     0     6     6     0     8    0
knotepl    120     3531    0     3482     2     0     2     2     0     8    0
kqueuepl   184       43    0       32     1     0     1     1     0     8    0
pipepl     304      155    0      128     3     0     3     3     0     8    0
fdescpl    448      592    0      564     5     0     5     5     0     8    1
filepl     120     2214    0     2015     8     0     8     8     0     8    0
lockfpl    104       26    0       24     1     0     1     1     0     8    0
lockfspl    48       13    0       11     1     0     1     1     0     8    0
sessionpl  144       99    0       91     1     0     1     1     0     8    0
pgrppl      48      117    0      101     1     0     1     1     0     8    0
ucredpl    104      195    0      184     1     0     1     1     0     8    0
zombiepl   144      564    0      564     1     0     1     1     0     8    1
processpl  1152     605    0      564     4     0     4     4     0     8    0
procpl     664      720    0      676     6     0     6     6     0     8    1
sockpl     552      247    0      222     3     0     3     3     0     8    1
mcl64k     65536      1    0        1     1     0     1     1     0     8    1
mcl16k     16384      1    0        1     1     0     1     1     0     8    1
mcl12k     12288      1    0        0     1     0     1     1     0     8    0
mcl8k      8192       4    0        4     1     0     1     1     0     8    1
mcl4k      4096    2555    0     2498    14     0    14    14     0     8    6
mcl2k      2048     451    0      451     1     0     1     1     0     8    1
mextrefs    64       80    0       79     1     0     1     1     0     8    0
mtagpl      96        4    0        4     1     0     1     1     0     8    1
mbufpl     256     5478    0     5338    10     0    10    10     0     8    0
bufpl      272     2305    0      102   147     0   147   147     0     8    0
anonpl      24    96437    0    93652    21     0    21    21     0   187    1
amapchunkpl 152   11214    0    10857    21     0    21    21     0   158    6
amappl16   200     1366    0     1349     4     0     4     4     0     8    2
amappl15   192        7    0        7     1     0     1     1     0     8    1
amappl14   184      526    0      525     1     0     1     1     0     8    0
amappl13   176      131    0      121     1     0     1     1     0     8    0
amappl12   168      874    0      849     2     0     2     2     0     8    0
amappl11   160        5    0        5     1     0     1     1     0     8    1
amappl10   152       55    0       45     1     0     1     1     0     8    0
amappl9    144      275    0      275     1     0     1     1     0     8    1
amappl8    136      145    0      144     1     0     1     1     0     8    0
amappl7    128      159    0      148     1     0     1     1     0     8    0
amappl6    120      321    0      320     1     0     1     1     0     8    0
amappl5    112       93    0       86     1     0     1     1     0     8    0
amappl4    104      296    0      280     1     0     1     1     0     8    0
amappl3     96     2058    0     1991     3     0     3     3     0     8    0
amappl2     88      668    0      603     2     0     2     2     0     8    0
amappl1     80    11514    0    10975    13     0    13    13     0     8    0
amappl      88     3261    0     3138     4     0     4     4     0    92    0
uvmvnodes   80       97    0        0     2     0     2     2     0     8    0
dma4096    4096       1    0        1     1     0     1     1     0     8    1
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     0     1     1     0     8    1
dma128     128      253    0      253     1     0     1     1     0     8    1
dma64       64        6    0        6     1     0     1     1     0     8    1
dma32       32        7    0        7     1     0     1     1     0     8    1
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72        3    0        0     1     0     1     1     0     8    0
uaddrrnd    24      592    0      564     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      592    0      564     1     0     1     1     0     8    0
vmmpekpl   168     6498    0     6450     3     0     3     3     0     8    0
vmmpepl    168    46875    0    45221    82     0    82    82     0   357    7
vmsppl     368      591    0      564     4     0     4     4     0     8    1
rwobjpl     40    16230    0    15350    11     0    11    11     0     8    1
pdppl      4096    1190    0     1128   106    38    68    80     0     8    6
pvpl        32   256116    0   248843    78     0    78    78     0   265    7
pmappl     216      591    0      564     3     0     3     3     0     8    1
extentpl    40       46    0       28     1     0     1     1     0     8    0
phpool     112      520    0       38    14     0    14    14     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
wsmouseopen(4400,1,2000,ffff80002a7d27f0) at wsmouseopen+0x78 sys/dev/wscons/wsmouse.c:309
spec_open(ffff80002a7f5148) at spec_open+0x2d6 sys/kern/spec_vnops.c:150
VOP_OPEN(fffffd006fb63878,1,fffffd0007ffd618,ffff80002a7d27f0) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138
vn_open(ffff80002a7f53a0,1,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff80002a7d27f0,ffffff9c,200000000040,0,0,0,2529779ad1f2008a) at doopenat+0x352 sys/kern/vfs_syscalls.c:1163
sys_openat(ffff80002a7d27f0,ffff80002a7f5640,ffff80002a7f5590) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1102
syscall(ffff80002a7f5640) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7f5640) at syscall+0x962 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xdbeb5831a40, count: -8
ddb> machine ddbcpu 1
No such command
ddb> trace
wsmouseopen(4400,1,2000,ffff80002a7d27f0) at wsmouseopen+0x78 sys/dev/wscons/wsmouse.c:309
spec_open(ffff80002a7f5148) at spec_open+0x2d6 sys/kern/spec_vnops.c:150
VOP_OPEN(fffffd006fb63878,1,fffffd0007ffd618,ffff80002a7d27f0) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138
vn_open(ffff80002a7f53a0,1,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff80002a7d27f0,ffffff9c,200000000040,0,0,0,2529779ad1f2008a) at doopenat+0x352 sys/kern/vfs_syscalls.c:1163
sys_openat(ffff80002a7d27f0,ffff80002a7f5640,ffff80002a7f5590) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1102
syscall(ffff80002a7f5640) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7f5640) at syscall+0x962 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xdbeb5831a40, count: -8

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/12 14:35 openbsd ed62f65fdb3a 70a60e12 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: wsmouseopen
* Struck through repros no longer work on HEAD.