syzbot


protection_fault: memcmp (2)

Status: upstream: reported on 2026/03/28 07:48
Reported-by: syzbot+d494b03abc0962ba5ad9@syzkaller.appspotmail.com
First crash: 14d, last: 14d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd protection_fault: memcmp -1 1 213d 213d 0/3 auto-obsoleted due to no activity on 2025/12/09 11:21

Sample crash report:
kernel: protection fault trap, code=0
Stopped at      memcmp+0x16:    repe cmpsq      (%rsi),%es:(%rdi)
ddb{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
the kernel did not panic
ddb{1}> trace
memcmp() at memcmp+0x16
pipex_unlink_session_locked(ffff8000373b92b0) at pipex_unlink_session_locked+0x137 sys/net/pipex.c:-1
pipex_destroy_all_sessions(ffff8000015ea000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline]
pipex_destroy_all_sessions(ffff8000015ea000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151
pppacclose(637d,1,2000,ffff80003c3e4a88) at pppacclose+0x16f sys/net/if_pppx.c:1335
spec_close(ffff80002a31ca00) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd80693398c0,1,fffffd80097fd548,ffff80003c3e4a88) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8062f67d10,ffff80003c3e4a88) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8062f67d10,ffff80003c3e4a88) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd8062f67d10,ffff80003c3e4a88) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd8062f67d10,ffff80003c3e4a88) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff80003c3e4a88) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff80003c3e4a88,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003c3e4a88,ffff80002a31cd70,ffff80002a31ccc0) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a31cd70) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a31cd70) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x70bc49d91050, count: -14
ddb{1}> show registers
rdi               0xffff8000373b93b4
rsi               0xdeafbeaddeafbeb1
rbp               0xffff80002a31c8a0
rbx                              0xc
rdx                              0xc
rcx                              0x1
rax               0xffff8000299bdff0
r8                0xffffffffffffffff
r9                               0x1
r10               0xc923bc609a9e6dba
r11               0xf3da6bdb30b645e4
r12               0xffff8000373b93b4
r13                                0
r14               0xffff8000373b9c30
r15                              0x4
rip               0xffffffff81ef8236    memcmp+0x16
cs                               0x8
rflags                       0x10203    __ALIGN_SIZE+0xf203
rsp               0xffff80002a31c838
ss                              0x10
memcmp+0x16:    repe cmpsq      (%rsi),%es:(%rdi)
ddb{1}> show proc
PROC (syz-executor) tid=109021 pid=59199 tcnt=0 stat=onproc
    flags process=1008<EXITING,SINGLEEXIT> proc=2000<WEXIT>
    runpri=32, usrpri=52, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0xffff80003c3e4a88 scnt=-1 ecnt=1
    forw=0xffffffffffffffff, list=0xffff80003c3e4028,0xffffffff839efa38
    process=0xffff80003c3f61d0 user=0xffff80002a317000, vmspace=0xfffffd806c877b88
    estcpu=2, cpticks=18, pctcpu=0.17, user=0, sys=1, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 52584  443464  24226      0  3        0x82  nanoslp       syz-executor
 26800  259178      0      0  3     0x14200  acct          acct
 95463  266963  24226      0  3        0x82  piperd        syz-executor
 12677   37594  24226      0  3        0x82  piperd        syz-executor
 98941  279325  24226      0  3        0x82  piperd        syz-executor
 23508  199033  24226      0  3        0x82  piperd        syz-executor
 47014  271076  24226      0  3        0x82  nanoslp       syz-executor
 10883  313397  24226      0  3        0x82  piperd        syz-executor
 24226   66473   1465      0  3        0x82  nanoslp       syz-executor
  1465  280134  63037      0  3    0x10008a  sigsusp       ksh
 63037   32676     93      0  3        0x98  kqread        sshd-session
    93  427301  89405      0  3        0x92  kqread        sshd-session
 31823   56185      1      0  3    0x100083  ttyin         getty
 89405    3091      1      0  3        0x88  kqread        sshd
 34499  197822  82260     74  3   0x1100092  bpf           pflogd
 82260   15756      1      0  3        0x80  sbwait        pflogd
 80386  510644  85420     73  3   0x1100090  kqread        syslogd
 85420  368139      1      0  3    0x100082  sbwait        syslogd
 71771  457375      1      0  3    0x100080  kqread        resolvd
 36511  474461  83732     77  7    0x100013                dhcpleased
 60862   17846  83732     77  3    0x100092  kqread        dhcpleased
 83732   42135      1      0  3        0x80  kqread        dhcpleased
 55988  232724      0      0  3     0x14200  bored         smr
 93825  518793      0      0  3     0x14200  pgzero        zerothread
 16070  268795      0      0  3     0x14200  aiodoned      aiodoned
 96971  391833      0      0  3     0x14200  syncer        update
  3680  309563      0      0  3     0x14200  cleaner       cleaner
  7886  327419      0      0  3     0x14200  reaper        reaper
 22619  396308      0      0  3     0x14200  pgdaemon      pagedaemon
 87395   79970      0      0  3     0x14200  bored         viomb
 96291  376400      0      0  3  0x40014200  acpi0         acpi0
 76743  104879      0      0  3  0x40014200                idle1
 35169  217485      0      0  3     0x14200  bored         softnet1
 54767  363274      0      0  2     0x14200                softnet0
 35889  319898      0      0  3     0x14200  bored         systqmp
 52143  424488      0      0  3     0x14200  bored         systq
  2919  271968      0      0  3     0x14200  tmoslp        softclockmp
  3322  492023      0      0  3  0x40014200  tmoslp        softclock
 77507  497997      0      0  3  0x40014200                idle0
     1  376931      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
CPU 1:
exclusive mutex /syzkaller/managers/multicore/kernel/sys/net/pipex.c:78 r = 0 (0xffffffff838cfd70)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  mtx_enter+0x4b4 sys/kern/kern_lock.c:487
#2  pipex_destroy_all_sessions+0x2f sys/net/pipex.c:144
#3  pppacclose+0x16f sys/net/if_pppx.c:1335
#4  spec_close+0x417 sys/kern/spec_vnops.c:-1
#5  VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
#6  vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
#6  vn_closefile+0x12b sys/kern/vfs_vnops.c:615
#7  fdrop+0x121 sys/kern/kern_descrip.c:1281
#8  closef+0x192 sys/kern/kern_descrip.c:1265
#9  fdfree+0x116 sys/kern/kern_descrip.c:1196
#10 exit1+0x576 sys/kern/kern_exit.c:215
#11 sys_exit+0x1a sys/kern/kern_exit.c:-1
#12 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#12 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#13 Xsyscall+0x128
Process 54767 (softnet0) thread 0xffff8000ffffe7c8 (363274)
shared rwlock softnet0 r = 0 (0xffff80000002c078)
#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 11066  12090K   12282K 166960K     12449        0
            pcb    17     15K      17K 166960K       137        0
         rtable   209      7K       8K 166960K       447        0
             pf    34     17K      19K 166960K        83        0
         ifaddr    39      6K       7K 166960K        69        0
        ifgroup    55      2K       2K 166960K       106        0
         sysctl     1      1K       9K 166960K         5        0
       counters    74     37K      38K 166960K       110        0
       ioctlops     0      0K       4K 166960K      1506        0
            iov     0      0K      28K 166960K        12        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1364     86K      86K 166960K      1729        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K         4        0
         VM map     2      1K       1K 166960K         2        0
            sem     4      0K       0K 166960K         5        0
        dirhash    12      2K       2K 166960K        15        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    11     37K      93K 166960K       369        0
          sigio     0      0K       0K 166960K        11        0
           proc    72    115K     163K 166960K       593        0
        subproc    63      3K       5K 166960K       252        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    77      5K       7K 166960K       117        0
    ether_multi     1      0K       0K 166960K         2        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    67    307K     307K 166960K        67        0
           exec     0      0K       1K 166960K       466        0
   fusefs mount     1     32K      32K 166960K         1        0
     pfkey data     0      0K       0K 166960K         2        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   190    150K     172K 166960K      4892        0
       UVM aobj     7      2K       2K 166960K         7        0
     pinsyscall    36     72K     107K 166960K      1572        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K         4        0
            NDP    12      0K       2K 166960K        46        0
           temp    39   9074K    9138K 166960K     15368        0
         kqueue    13     20K      28K 166960K        45        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       51    0       48     1     0     1     1     0     8    0
rtentry    176      133    0       45     6     0     6     6     0     8    0
unpcb      144      167    0      150     4     0     4     4     0     8    3
syncache   336        4    0        4     2     1     1     1     0     8    1
tcpqe       32        1    0        1     1     0     1     1     0     8    1
tcpcb      736       38    0       33     1     0     1     1     0     8    0
arp        136       22    0        6     1     0     1     1     0     8    0
inpcb      328      484    0      476    12    10     2    12     0     8    1
nd6        152       30    0        9     1     0     1     1     0     8    0
pkpcb       40        2    0        2     2     1     1     1     0     8    1
kcovpl      48       28    0       21     1     0     1     1     0     8    0
ppxss      1192      13    0       11     3     2     1     1     0     8    0
pffrag     232        1    0        0     1     0     1     1     0   482    0
pffrnode    88        1    0        0     1     0     1     1     0     8    0
pffrent     40        1    0        0     1     0     1     1     0     8    0
pfosfp      40     1428    0     1005     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfstitem    24       34    0       11     1     0     1     1     0     8    0
pfstkey    128       34    0       11     2     0     2     2     0     8    0
pfstate    448       34    0       11     4     0     4     4     0     8    0
pfrule     1360      21    0       16     2     1     1     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      543    0      173    29     5    24    29     0     8    0
art_table   40      544    0      173     5     0     5     5     0     8    0
art_node    32      133    0       57     1     0     1     1     0     8    0
sysvmsgpl   40        1    0        1     1     0     1     1     0     8    1
semapl     112        2    0        0     1     0     1     1     0     8    0
shmpl      112        4    0        0     1     0     1     1     0     8    0
dirhash    1024      19    0        2     3     0     3     3     0     8    0
dino2pl    256     1910    0      424    94     0    94    94     0     8    0
ffsino     296     1910    0      424   115     0   115   115     0     8    0
nchpl      144     2321    0      603    64     0    64    64     0     8    0
rtmask      32        2    0        1     2     1     1     1     0     8    0
vnodes     216     2296    0        0   128     0   128   128     0     8    0
namei      1024    7939    0     7939     1     0     1     1     0     8    1
percpumem   16       70    0       18     1     0     1     1     0     8    0
kstatmem   264       60    0       32     5     2     3     3     0     8    1
scsiplug    72        2    0        2     2     1     1     1     0     8    1
scxspl     216     8029    0     8029    11     3     8     8     1     8    8
plimitpl   152       68    0       50     1     0     1     1     0     8    0
sigapl     424      653    0      611     7     1     6     7     0     8    0
knotepl    120      289    0        0     9     0     9     9     0     8    0
kqueuepl   224       70    0       60     1     0     1     1     0     8    0
pipepl     344      203    0      176     3     0     3     3     0     8    0
fdescpl    528      636    0      611     3     0     3     3     0     8    1
filepl     160     3318    0     3113    22     6    16    16     0     8    5
lockfpl    104      120    0      118     1     0     1     1     0     8    0
lockfspl    48       26    0       24     1     0     1     1     0     8    0
sessionpl  144       44    0       35     1     0     1     1     0     8    0
pgrppl      48      138    0      122     1     0     1     1     0     8    0
ucredpl    104      217    0      203     1     0     1     1     0     8    0
zombiepl   144      613    0      611     1     0     1     1     0     8    0
processpl  1232     653    0      611     5     0     5     5     0     8    0
procpl     664      946    0      904     6     1     5     6     0     8    0
sockpl     752      705    0      677    24    14    10    17     0     8    6
mcl64k     65536      5    0        0     1     0     1     1     0     8    0
mcl16k     16384      3    0        0     1     0     1     1     0     8    0
mcl8k      8192       3    0        0     1     0     1     1     0     8    0
mcl4k      4096     115    0        0    15     0    15    15     0     8    0
mcl2k      2048      16    0        0     2     0     2     2     0     8    0
mtagpl      96        7    0        0     1     0     1     1     0     8    0
mbufpl     256      239    0        0    15     0    15    15     0     8    0
bufpl      280     2759    0      106   190     0   190   190     0     8    0
anonpl      32     5411    0        0    44     0    44    44     0   246    0
amapchunkpl 152   14602    0    14253    25     5    20    25     0   158    3
amappl16   200     2085    0     2066     5     3     2     5     0     8    0
amappl15   192        4    0        4     1     1     0     1     0     8    0
amappl14   184      449    0      448     1     0     1     1     0     8    0
amappl13   176      130    0      118     1     0     1     1     0     8    0
amappl12   168      917    0      893     2     0     2     2     0     8    0
amappl11   160        2    0        2     1     1     0     1     0     8    0
amappl10   152       68    0       54     1     0     1     1     0     8    0
amappl9    144      262    0      262     1     1     0     1     0     8    0
amappl8    136      112    0      110     1     0     1     1     0     8    0
amappl7    128      159    0      146     1     0     1     1     0     8    0
amappl6    120      173    0      171     1     0     1     1     0     8    0
amappl5    112      111    0      100     1     0     1     1     0     8    0
amappl4    104      304    0      282     1     0     1     1     0     8    0
amappl3     96     2686    0     2604     3     0     3     3     0     8    0
amappl2     88      556    0      494     2     0     2     2     0     8    0
amappl1     80    10833    0    10251    18     2    16    16     0     8    3
amappl      88     4082    0     3962     4     0     4     4     0    92    0
uvmvnodes   80      104    0        0     3     0     3     3     0     8    0
dma32768   32768      1    0        1     1     1     0     1     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      254    0      254     2     2     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        6    0        0     1     0     1     1     0     8    0
uaddrrnd    24      636    0      611     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      636    0      611     1     0     1     1     0     8    0
vmmpekpl   168     7492    0     7448     3     0     3     3     0     8    0
vmmpepl    168    49404    0    47790    95     5    90    90     0   357    8
vmsppl     488      635    0      611     5     1     4     5     0     8    0
rwobjpl     80    16789    0    15812    24     0    24    24     0     8    0
pdppl      4096    1279    0     1222   113    44    69    87     0     8   12
pvpl        32    11124    0        0    91     1    90    90     0   265    0
pmappl     256      635    0      611     3     1     2     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      293    0       55     8     0     8     8     0     8    0
ddb{1}> machine ddbcpu 0
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
ddb{0}> trace
x86_ipi_db(ffffffff838f7ff0) 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(ffffffff839700c0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff839700c0) at __mp_lock+0x192 sys/kern/kern_lock.c:173
ktrsysret(ffff80002a242d08,48,0,ffff80002a27a270) at ktrsysret+0xde ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrsysret(ffff80002a242d08,48,0,ffff80002a27a270) at ktrsysret+0xde sys/kern/kern_ktrace.c:209
syscall(ffff80002a27a320) at syscall+0xa51 mi_syscall_return sys/sys/syscall_mi.h:204 [inline]
syscall(ffff80002a27a320) at syscall+0xa51 sys/arch/amd64/amd64/trap.c:804
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71e9fedfdc30, count: -7
ddb{0}> machine ddbcpu 1
Stopped at      memcmp+0x16:    repe cmpsq      (%rsi),%es:(%rdi)
ddb{1}> trace
memcmp() at memcmp+0x16
pipex_unlink_session_locked(ffff8000373b92b0) at pipex_unlink_session_locked+0x137 sys/net/pipex.c:-1
pipex_destroy_all_sessions(ffff8000015ea000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline]
pipex_destroy_all_sessions(ffff8000015ea000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151
pppacclose(637d,1,2000,ffff80003c3e4a88) at pppacclose+0x16f sys/net/if_pppx.c:1335
spec_close(ffff80002a31ca00) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd80693398c0,1,fffffd80097fd548,ffff80003c3e4a88) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8062f67d10,ffff80003c3e4a88) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8062f67d10,ffff80003c3e4a88) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd8062f67d10,ffff80003c3e4a88) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd8062f67d10,ffff80003c3e4a88) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff80003c3e4a88) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff80003c3e4a88,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003c3e4a88,ffff80002a31cd70,ffff80002a31ccc0) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a31cd70) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a31cd70) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x70bc49d91050, count: -14

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/28 07:48 openbsd 9d790fdba930 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore protection_fault: memcmp
* Struck through repros no longer work on HEAD.