syzbot


protection_fault: memcmp

Status: upstream: reported on 2025/09/10 11:21
Reported-by: syzbot+43738b7a0f9af671a3fb@syzkaller.appspotmail.com
First crash: 2d18h, last: 2d18h

Sample crash report:
kernel: protection fault trap, code=0
Stopped at      memcmp+0x16:    repe cmpsq      (%rsi),%es:(%rdi)
ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
the kernel did not panic
ddb{0}> trace
memcmp() at memcmp+0x16
pipex_unlink_session_locked(ffff80003c440000) at pipex_unlink_session_locked+0x11f sys/net/pipex.c:-1
pipex_destroy_all_sessions(ffff80000148c000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline]
pipex_destroy_all_sessions(ffff80000148c000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:154
pppacclose(637e,41,2000,ffff80003c4262c0) at pppacclose+0x16f sys/net/if_pppx.c:1335
spec_close(ffff80003c413500) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd806b5592b0,41,fffffd80097fb478,ffff80003c4262c0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8069421b88,ffff80003c4262c0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8069421b88,ffff80003c4262c0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd8069421b88,ffff80003c4262c0) at fdrop+0x121 sys/kern/kern_descrip.c:1280
closef(fffffd8069421b88,ffff80003c4262c0) at closef+0x192 sys/kern/kern_descrip.c:1264
fdfree(ffff80003c4262c0) at fdfree+0x116 sys/kern/kern_descrip.c:1195
exit1(ffff80003c4262c0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003c4262c0,ffff80003c413870,ffff80003c4137c0) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c413870) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c413870) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:746
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x76d15293ea40, count: -14
ddb{0}> show registers
rdi               0xffff80003c440104
rsi               0xdeafbeaddeafbeb1
rbp               0xffff80003c4133a0
rbx                              0xc
rdx                              0xc
rcx                              0x1
rax               0xffffffff837bdff0    cpu_info_full_primary+0x1ff0
r8                0xffffffffffffffff
r9                                 0
r10               0x5af7fb8026a51ff6
r11               0x401cd069cd1b8810
r12               0xffff80003c440104
r13                                0
r14               0xffff80003c4412d0
r15                              0x4
rip               0xffffffff810b2d36    memcmp+0x16
cs                               0x8
rflags                       0x10203    __ALIGN_SIZE+0xf203
rsp               0xffff80003c413338
ss                                 0
memcmp+0x16:    repe cmpsq      (%rsi),%es:(%rdi)
ddb{0}> show proc
PROC (syz-executor) tid=518307 pid=53593 tcnt=0 stat=onproc
    flags process=1008<EXITING,SINGLEEXIT> proc=2000<WEXIT>
    runpri=32, usrpri=86, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0xffff80003c4262c0 scnt=-1 ecnt=1
    forw=0xffffffffffffffff, list=0xffff80003c426fb8,0xffff80003c426038
    process=0xffff80002a3d04e8 user=0xffff80003c40e000, vmspace=0xfffffd806b7ce7c0
    estcpu=36, cpticks=6, pctcpu=0.0, user=0, sys=0, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 98805  522641  17389      0  2           0                syz-executor
 98805  453070  17389      0  3   0x4000080  msgwait       syz-executor
 98805  155887  17389      0  3   0x4000080  msgwait       syz-executor
 48258  445441  13451      0  3        0x80  nanoslp       syz-executor
 48258  251327  13451      0  2   0x4000000                syz-executor
 48258   37172  13451      0  3   0x4000080  fsleep        syz-executor
 74178  148700  20105      0  2           0                syz-executor
 74178   76693  20105      0  3   0x4000080  fsleep        syz-executor
 14264  132885  93339      0  3        0x80  nanoslp       syz-executor
 14264  169879  93339      0  3   0x4000080  bell          syz-executor
 14264  484674  93339      0  3   0x4000080  fsleep        syz-executor
 79578  230845  42842      0  3        0x80  nanoslp       syz-executor
 79578  118951  42842      0  3   0x4000080  fsleep        syz-executor
 79578  283103  42842      0  3   0x4000080  ttyin         syz-executor
 79578  310904  42842      0  3   0x4000080  fsleep        syz-executor
 17389  516112  56005      0  2         0x2                syz-executor
 42842  257604  56005      0  3        0x82  nanoslp       syz-executor
 13451  182020  56005      0  3        0x82  nanoslp       syz-executor
 93339  118583  56005      0  3        0x82  nanoslp       syz-executor
 81150  208474  56005      0  3        0x82  nanoslp       syz-executor
 14294  386944  56005      0  7         0x2                syz-executor
 20105  466786  56005      0  3        0x82  nanoslp       syz-executor
 12753  296000  56005      0  3        0x82  nanoslp       syz-executor
 56005  141560  22407      0  3        0x82  kqread        syz-executor
 22407  152354  14603      0  3    0x10008a  sigsusp       ksh
 14603   84991  15313      0  3        0x98  kqread        sshd-session
 15313  260458  99281      0  3        0x92  kqread        sshd-session
 94395  359026      1      0  3    0x100083  ttyin         getty
 99281  511537      1      0  3        0x88  kqread        sshd
 37300  159863  88687     74  3   0x1100092  bpf           pflogd
 88687  325192      1      0  3        0x80  sbwait        pflogd
 71033  241073  99343     73  3   0x1100090  kqread        syslogd
 99343  454731      1      0  3    0x100082  sbwait        syslogd
 71546  417218      1      0  3    0x100080  kqread        resolvd
 59948  506728  64116     77  2    0x100012                dhcpleased
 16189  468382  64116     77  3    0x100092  kqread        dhcpleased
 64116  353442      1      0  3        0x80  kqread        dhcpleased
 84232  458773      0      0  3     0x14200  bored         smr
 52422  198248      0      0  3     0x14200  pgzero        zerothread
 51848  432225      0      0  3     0x14200  aiodoned      aiodoned
 82051  413180      0      0  3     0x14200  syncer        update
 59221  473483      0      0  3     0x14200  cleaner       cleaner
 48722  460689      0      0  3     0x14200  reaper        reaper
 11947   96590      0      0  3     0x14200  pgdaemon      pagedaemon
 86316  400537      0      0  3     0x14200  bored         viomb
 20805  134499      0      0  3  0x40014200  acpi0         acpi0
 19305   19496      0      0  3  0x40014200                idle1
 39450   87163      0      0  3     0x14200  bored         softnet1
 56334  521377      0      0  2     0x14200                softnet0
 43677  402400      0      0  3     0x14200  bored         systqmp
 76737  505129      0      0  3     0x14200  bored         systq
 24471  126428      0      0  3     0x14200  tmoslp        softclockmp
 22182  257703      0      0  3  0x40014200  tmoslp        softclock
 21263  302905      0      0  3  0x40014200                idle0
     1  439821      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
CPU 0:
exclusive mutex /syzkaller/managers/multicore/kernel/sys/net/pipex.c:78 r = 0 (0xffffffff837db5d0)
#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_try+0x1ad sys/kern/kern_lock.c:311
#2  mtx_enter+0x62 sys/kern/kern_lock.c:261
#3  pipex_destroy_all_sessions+0x2f sys/net/pipex.c:147
#4  pppacclose+0x16f sys/net/if_pppx.c:1335
#5  spec_close+0x417 sys/kern/spec_vnops.c:-1
#6  VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
#7  vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
#7  vn_closefile+0x12b sys/kern/vfs_vnops.c:615
#8  fdrop+0x121 sys/kern/kern_descrip.c:1280
#9  closef+0x192 sys/kern/kern_descrip.c:1264
#10 fdfree+0x116 sys/kern/kern_descrip.c:1195
#11 exit1+0x576 sys/kern/kern_exit.c:215
#12 sys_exit+0x1a sys/kern/kern_exit.c:-1
#13 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#13 syscall+0xb17 sys/arch/amd64/amd64/trap.c:746
#14 Xsyscall+0x128
Process 56334 (softnet0) thread 0xffff8000ffffe530 (521377)
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{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 10205  11153K   11264K 166960K     11340        0
            pcb    17     12K      12K 166960K        29        0
         rtable   210      7K       7K 166960K       272        0
             pf    34     17K      19K 166960K        57        0
         ifaddr    43      7K       7K 166960K        51        0
        ifgroup    55      2K       2K 166960K        63        0
         sysctl     1      1K       9K 166960K         5        0
       counters    70     37K      38K 166960K        84        0
       ioctlops     0      0K       4K 166960K      1495        0
            iov     0      0K       2K 166960K         4        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1347     85K      85K 166960K      1401        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       9K 166960K         5        0
         VM map     2      1K       1K 166960K         2        0
            sem     7      0K       0K 166960K        10        0
        dirhash    12      2K       2K 166960K        15        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    18     65K      93K 166960K       181        0
           proc    71    115K     180K 166960K       533        0
        subproc    72      4K       4K 166960K        72        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        13        0
       in_multi    99      7K       7K 166960K       108        0
    ether_multi     1      0K       0K 166960K         1        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    61    281K     281K 166960K        61        0
           exec     0      0K       1K 166960K       377        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   255    160K     169K 166960K      3454        0
       UVM aobj     5      2K       2K 166960K         5        0
     pinsyscall    43     86K     107K 166960K      1292        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     2      0K       0K 166960K         8        0
            NDP    14      0K       1K 166960K        32        0
           temp    37   8638K    8702K 166960K      4776        0
         kqueue    13     20K      28K 166960K        31        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       42    0       39     1     0     1     1     0     8    0
rtentry    176       95    0        1     5     0     5     5     0     8    0
unpcb      144       41    0       24     1     0     1     1     0     8    0
syncache   336        3    0        3     1     0     1     1     0     8    1
tcpcb      736       22    0       16     1     0     1     1     0     8    0
arp        136       10    0        0     1     0     1     1     0     8    0
inpcb      328      109    0       98     2     0     2     2     0     8    1
nd6        144       16    0        0     1     0     1     1     0     8    0
kcovpl      48        8    0        0     1     0     1     1     0     8    0
ppxss      1192       8    0        7     1     0     1     1     0     8    0
pffrag     232        3    0        0     1     0     1     1     0   482    0
pffrnode    88        3    0        0     1     0     1     1     0     8    0
pffrent     40        4    0        1     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
pftag       88        1    0        1     1     0     1     1     0     8    1
pfstitem    24       17    0        0     1     0     1     1     0     8    0
pfstkey    128       17    0        0     1     0     1     1     0     8    0
pfstate    384       17    0        0     2     0     2     2     0     8    0
pfrule     1344      24    0       18     2     0     2     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      437    0        0    28     0    28    28     0     8    0
art_table   40      438    0        0     5     0     5     5     0     8    0
art_node    32       95    0       11     1     0     1     1     0     8    0
sysvmsgpl   40        1    0        0     1     0     1     1     0     8    0
semapl     112        7    0        2     1     0     1     1     0     8    0
shmpl      112        2    0        0     1     0     1     1     0     8    0
dirhash    1024      19    0        2     3     0     3     3     0     8    0
dino2pl    256     1648    0      134    96     0    96    96     0     8    0
ffsino     296     1648    0      134   117     0   117   117     0     8    0
nchpl      144     1890    0      195    63     0    63    63     0     8    0
rtmask      32        2    0        1     1     0     1     1     0     8    0
uvmvnodes   80     1757    0        0    36     0    36    36     0     8    0
vnodes     216     1757    0        0    98     0    98    98     0     8    0
namei      1024    5794    0     5794     1     0     1     1     0     8    1
percpumem   16       57    0        7     1     0     1     1     0     8    0
kstatmem   264       34    0        8     3     0     3     3     0     8    1
scxspl     216     6763    0     6763     3     1     2     2     1     8    2
plimitpl   152       34    0       17     1     0     1     1     0     8    0
sigapl     424      487    0      439     7     0     7     7     0     8    1
knotepl    120      312    0        0    10     0    10    10     0     8    0
kqueuepl   224       38    0       28     2     0     2     2     0     8    1
pipepl     344      107    0       80     3     0     3     3     0     8    0
fdescpl    528      471    0      439     3     0     3     3     0     8    0
filepl     160     1670    0     1436    10     0    10    10     0     8    0
lockfpl    104       25    0       22     1     0     1     1     0     8    0
lockfspl    48       13    0       10     1     0     1     1     0     8    0
sessionpl  144       22    0       13     1     0     1     1     0     8    0
pgrppl      48       30    0       13     1     0     1     1     0     8    0
ucredpl    104      125    0      111     1     0     1     1     0     8    0
zombiepl   144      442    0      439     1     0     1     1     0     8    0
processpl  1232     487    0      439     5     0     5     5     0     8    1
procpl     664      581    0      523     6     0     6     6     0     8    1
sockpl     752      193    0      162     4     0     4     4     0     8    0
mcl64k     65536      2    0        0     1     0     1     1     0     8    0
mcl16k     16384      2    0        0     1     0     1     1     0     8    0
mcl8k      8192       3    0        0     1     0     1     1     0     8    0
mcl4k      4096     113    0        0    15     0    15    15     0     8    0
mcl2k      2048      29    0        0     4     0     4     4     0     8    0
mtagpl      96        2    0        0     1     0     1     1     0     8    0
mbufpl     256      140    0        0     9     0     9     9     0     8    0
bufpl      280     3017    0      122   207     0   207   207     0     8    0
anonpl      32     3960    0        0    32     0    32    32     0   246    0
amapchunkpl 152    9789    0     9244    22     1    21    21     0   158    0
amappl16   200     2008    0     1981     5     1     4     5     0     8    2
amappl15   192       10    0       10     2     1     1     1     0     8    1
amappl14   184      115    0      103     1     0     1     1     0     8    0
amappl13   176        3    0        3     1     1     0     1     0     8    0
amappl12   168     1127    0     1095     4     1     3     3     0     8    1
amappl11   160       56    0       42     1     0     1     1     0     8    0
amappl10   152       12    0       12     1     1     0     1     0     8    0
amappl9    144      251    0      250     1     0     1     1     0     8    0
amappl8    136       27    0       25     1     0     1     1     0     8    0
amappl7    128      107    0       95     1     0     1     1     0     8    0
amappl6    120      183    0      180     1     0     1     1     0     8    0
amappl5    112      125    0      116     1     0     1     1     0     8    0
amappl4    104      314    0      293     1     0     1     1     0     8    0
amappl3     96     1507    0     1398     4     1     3     3     0     8    0
amappl2     88      701    0      624     2     0     2     2     0     8    0
amappl1     80     8470    0     7859    15     0    15    15     0     8    2
amappl      88     2758    0     2575     5     0     5     5     0    92    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        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        4    0        0     1     0     1     1     0     8    0
uaddrrnd    24      471    0      439     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      471    0      439     1     0     1     1     0     8    0
vmmpekpl   168     5438    0     5406     2     0     2     2     0     8    0
vmmpepl    168    36933    0    34897    89     0    89    89     0   357    0
vmsppl     488      470    0      439     5     0     5     5     0     8    1
rwobjpl     80    14832    0    12121    56     0    56    56     0     8    0
pdppl      4096     950    0      878   108    32    76    88     0     8    4
pvpl        32    10556    0        0    86     0    86    86     0   265    0
pmappl     256      470    0      439     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      276    0       34     8     0     8     8     0     8    0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
memcmp() at memcmp+0x16
pipex_unlink_session_locked(ffff80003c440000) at pipex_unlink_session_locked+0x11f sys/net/pipex.c:-1
pipex_destroy_all_sessions(ffff80000148c000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline]
pipex_destroy_all_sessions(ffff80000148c000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:154
pppacclose(637e,41,2000,ffff80003c4262c0) at pppacclose+0x16f sys/net/if_pppx.c:1335
spec_close(ffff80003c413500) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd806b5592b0,41,fffffd80097fb478,ffff80003c4262c0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8069421b88,ffff80003c4262c0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8069421b88,ffff80003c4262c0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd8069421b88,ffff80003c4262c0) at fdrop+0x121 sys/kern/kern_descrip.c:1280
closef(fffffd8069421b88,ffff80003c4262c0) at closef+0x192 sys/kern/kern_descrip.c:1264
fdfree(ffff80003c4262c0) at fdfree+0x116 sys/kern/kern_descrip.c:1195
exit1(ffff80003c4262c0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003c4262c0,ffff80003c413870,ffff80003c4137c0) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c413870) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c413870) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:746
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x76d15293ea40, count: -14
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
ddb{1}> trace
x86_ipi_db(ffff8000299edff0) 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(ffffffff839678b8) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline]
__mp_lock(ffffffff839678b8) at __mp_lock+0x192 sys/kern/kern_lock.c:165
syscall(ffff80002a3387e0) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
syscall(ffff80002a3387e0) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:746
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x771551d67d30, count: -6

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/10 11:21 openbsd 98139c2399bf fdeaa69b .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore protection_fault: memcmp
* Struck through repros no longer work on HEAD.