syzbot


protection_fault: icmp_mtudisc_timeout (4)

Status: upstream: reported on 2025/07/16 23:24
Reported-by: syzbot+5de334298738b60f07ab@syzkaller.appspotmail.com
First crash: 49d, last: 22d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd protection_fault: icmp_mtudisc_timeout (2) -1 1 357d 357d 0/3 auto-obsoleted due to no activity on 2024/12/10 05:16
openbsd protection_fault: icmp_mtudisc_timeout -1 3 519d 572d 0/3 auto-obsoleted due to no activity on 2024/07/01 04:08
openbsd protection_fault: icmp_mtudisc_timeout (3) -1 1 195d 195d 0/3 auto-obsoleted due to no activity on 2025/05/21 20:37

Sample crash report:
kernel: protection fault trap, code=0
Stopped at      icmp_mtudisc_timeout+0x123:     movq    0(%rax),%rcx
ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
the kernel did not panic
ddb{0}> trace
icmp_mtudisc_timeout(fffffd806b6790c0,0) at icmp_mtudisc_timeout+0x123 sys/netinet/ip_icmp.c:1102
rt_timer_queue_flush(ffffffff839813a8) at rt_timer_queue_flush+0x28d sys/net/route.c:1586
ip_sysctl(ffff80002a346eac,1,0,ffff80002a346ed8,200000001300,4) at ip_sysctl+0x84d sys/netinet/ip_input.c:1750
net_sysctl(ffff80002a346ea4,3,0,ffff80002a346ed8,200000001300,4,4fc51ea41072f126) at net_sysctl+0x64e sys/kern/uipc_domain.c:260
sys_sysctl(ffff80002a322fd0,ffff80002a347010,ffff80002a346f60) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80002a347010) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a347010) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:748
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x551d5d2cc00, count: -7
ddb{0}> show registers
rdi                             0x14
rsi                             0x14
rbp               0xffff80002a346ce0
rbx               0xffff80002a346c01
rdx               0xffff80000147d4c0
rcx               0xffff80002a322fd0
rax               0x63d329d1220e24c9
r8                0xffffffff82047f10    tcp_mtudisc_increase
r9                                 0
r10               0x6ccc95ce3e65378f
r11               0xb8c5f8cae0759052
r12               0xffff800000039058
r13                             0x14
r14                                0
r15               0xfffffd806b6790c0
rip               0xffffffff828f5243    icmp_mtudisc_timeout+0x123
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002a346c90
ss                              0x10
icmp_mtudisc_timeout+0x123:     movq    0(%rax),%rcx
ddb{0}> show proc
PROC (syz-executor) tid=207268 pid=38707 tcnt=2 stat=onproc
    flags process=0 proc=4000000<THREAD>
    runpri=50, usrpri=50, slppri=17, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a3222d8,0xffff80002a322818
    process=0xffff80003c4d1888 user=0xffff80002a342000, vmspace=0xfffffd806b8b73f0
    estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
   419  340270  40296      0  7           0                syz-executor
   419   79053  40296      0  2   0x4000000                syz-executor
 22171   69027   4381      0  2           0                syz-executor
 38707  414076  10517      0  2           0                syz-executor
*38707  207268  10517      0  7   0x4000000                syz-executor
 70985  301713  72640      0  2           0                syz-executor
 46255  510732  91928      0  2         0x2                arp
 91928   79370  58273      0  3    0x10008a  sigsusp       sh
  6211  431339  82201      0  2           0                syz-executor
  6211  382271  82201      0  3   0x4000080  netcon        syz-executor
  6211  367967  82201      0  3   0x4000080  fsleep        syz-executor
 58273  143130  66262      0  3        0x82  wait          syz-executor
 33193  390601      0      0  3     0x14200  acct          acct
 85366  485643  87015      0  3        0x82  sbwait        sshd-session
 46127   55297  87015      0  3        0x82  sbwait        sshd-session
 72640  330649  66262      0  2         0x3                syz-executor
 31059  445228      1      0  3    0x100083  ttyin         getty
  4381  197831  66262      0  2         0x3                syz-executor
 10517  282669  66262      0  3        0x82  nanoslp       syz-executor
   466  269689      0      0  3     0x14200  bored         sosplice
 40296  392238  66262      0  2         0x3                syz-executor
 60443  141391  66262      0  2         0x3                syz-executor
 39542  519559  66262      0  2         0x3                syz-executor
 82201  117138  66262      0  2         0x2                syz-executor
 66262   14180  88540      0  2         0x3                syz-executor
 88540  120269  68217      0  3    0x10008a  sigsusp       ksh
 68217  261553  19870      0  3        0x98  kqread        sshd-session
 19870    7823  87015      0  3        0x92  kqread        sshd-session
 87015  351290      1      0  3        0x88  kqread        sshd
 13377  351993  14332     74  3   0x1100092  bpf           pflogd
 14332  420077      1      0  3        0x80  sbwait        pflogd
 93987   34124  80624     73  3   0x1100090  kqread        syslogd
 80624  443049      1      0  3    0x100082  sbwait        syslogd
 80688  248579      1      0  3    0x100080  kqread        resolvd
 89987  242601  19750     77  3    0x100092  kqread        dhcpleased
  6844  163203  19750     77  3    0x100092  kqread        dhcpleased
 19750  423177      1      0  3        0x80  kqread        dhcpleased
 37292  469626      0      0  3     0x14200  bored         smr
 25395  436603      0      0  2     0x14200                zerothread
 80780  135891      0      0  3     0x14200  aiodoned      aiodoned
 34579  216951      0      0  3     0x14200  syncer        update
 87691   92600      0      0  3     0x14200  cleaner       cleaner
 29086    2510      0      0  3     0x14200  reaper        reaper
 23249  310260      0      0  3     0x14200  pgdaemon      pagedaemon
 12986  269677      0      0  3     0x14200  bored         viomb
 80363   68215      0      0  3  0x40014200  acpi0         acpi0
 67819  512103      0      0  3  0x40014200                idle1
 26921   82911      0      0  3     0x14200  bored         softnet7
 83026  415582      0      0  3     0x14200  bored         softnet6
 61423   36280      0      0  3     0x14200  bored         softnet5
  4332   99991      0      0  3     0x14200  bored         softnet4
 67704  285596      0      0  3     0x14200  bored         softnet3
 73621   86963      0      0  3     0x14200  bored         softnet2
 96244  420446      0      0  3     0x14200  bored         softnet1
 65536  340465      0      0  3     0x14200  bored         softnet0
 58894  501155      0      0  2     0x14200                systqmp
  7413  369590      0      0  3     0x14200  bored         systq
 47802  229862      0      0  3     0x14200  tmoslp        softclockmp
 37196  346917      0      0  3  0x40014200  tmoslp        softclock
 31007  468894      0      0  3  0x40014200                idle0
     1  314881      0      0  3     0x80082  wait          init
     0       0     -1      0  3  0x10010200  scheduler     swapper
ddb{0}> show all locks
Process 38707 (syz-executor) thread 0xffff80002a322fd0 (207268)
exclusive rwlock netlock r = 0 (0xffffffff837b8b60)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2  ip_sysctl+0x838 sys/netinet/ip_input.c:1749
#3  net_sysctl+0x64e sys/kern/uipc_domain.c:260
#4  sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
#5  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#5  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:748
#6  Xsyscall+0x128
Process 46255 (arp) thread 0xffff80002a323500 (510732)
exclusive rwlock vmmaplk r = 0 (0xfffffd806e3e44e0)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2  vm_map_lock_ln+0x12e sys/uvm/uvm_map.c:5168
#3  uvm_map_protect+0xe0 sys/uvm/uvm_map.c:3064
#4  sys_mprotect+0x351 sys/uvm/uvm_mmap.c:590
#5  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#5  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:748
#6  Xsyscall+0x128
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 10274  11235K   11774K 166960K     15026        0
            pcb    17     17K      30K 166960K       802        0
         rtable   201     13K      14K 166960K       911        0
             pf    44     19K      83K 166960K       301        0
         ifaddr    37      6K       9K 166960K       209        0
        ifgroup    65      2K       3K 166960K       356        0
         sysctl     4      1K       9K 166960K        87        0
       counters    70     37K      38K 166960K       452        0
       ioctlops     0      0K       4K 166960K      2185        0
            iov     0      0K      32K 166960K       142        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1528     96K      96K 166960K      4290        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      2K       6K 166960K        26        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K       151        0
        dirhash    12      2K       2K 166960K        51        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    18     65K     240K 166960K      2811        0
          sigio     1      0K       0K 166960K        39        0
           proc    72    115K     164K 166960K      1253        0
        subproc    72      4K       4K 166960K       198        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       468        0
       in_multi    70      5K       7K 166960K       317        0
    ether_multi     1      0K       0K 166960K        27        0
            mrt     2      0K       0K 166960K        20        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   235   1049K    1049K 166960K       235        0
           exec     0      0K       1K 166960K      1110        0
   fusefs mount     1     32K      32K 166960K         1        0
     pfkey data     0      0K       0K 166960K         3        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   242    180K     194K 166960K     27093        0
       UVM aobj    55      2K       2K 166960K        62        0
     pinsyscall    47     94K     105K 166960K      4279        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K       152        0
            NDP    13      0K       2K 166960K       156        0
           temp    78   8652K    8778K 166960K    124010        0
         kqueue    13     20K      32K 166960K       515        0
      SYN cache     2      8K      16K 166960K         3        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      356    0      352     4     3     1     3     0     8    0
rtentry    176      283    0      213     5     0     5     5     0     8    0
unpcb      144     2406    0     2385    19    17     2     6     0     8    0
syncache   336       11    0       11     2     2     0     1     0     8    0
tcpqe       32        3    0        3     1     1     0     1     0     8    0
tcpcb      736      907    0      893    15    13     2     7     0     8    0
arp        128       34    0       22     1     0     1     1     0     8    0
inpcb      328     2977    0     2959    28    23     5    13     0     8    2
nd6        144       53    0       38     1     0     1     1     0     8    0
pkpcb       40       83    0       83     5     4     1     1     0     8    1
kcovpl      48       22    0       14     1     0     1     1     0     8    0
mppekey    1024       2    0        2     1     1     0     1     0     8    0
ppxss      1192     156    0      156     2     1     1     1     0     8    1
pppxif     1504      10    0       10     6     6     0     1     0     8    0
pfstscr     40        5    0        4     1     0     1     1     0     8    0
pffrag     232       22    0       12     1     0     1     1     0   482    0
pffrnode    88       20    0       10     1     0     1     1     0     8    0
pffrent     40       41    0       30     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       1    0        1     1     1     0     1     0     8    0
pfanchor   1288       1    0        0     1     0     1     1     0     8    0
pfstitem    24      198    0       70     1     0     1     1     0     8    0
pfstkey    128      332    0      204     5     0     5     5     0     8    0
pfstate    384      264    0      137    14     0    14    14     0     8    0
pfrule     1344      28    0       23     2     1     1     2     0     8    0
rttmr      136        7    0        6     2     1     1     1     0     8    0
art_heap8  4096       3    0        0     3     0     3     3     0     8    0
art_heap4  256     1296    0      999    36    10    26    30     0     8    1
art_table   40     1299    0      999     5     0     5     5     0     8    0
art_node    32      281    0      219     1     0     1     1     0     8    0
sysvmsgpl   40       12    0        9     2     1     1     1     0     8    0
semupl     112        1    0        1     1     1     0     1     0     8    0
semapl     112      146    0      135     1     0     1     1     0     8    0
shmpl      112       59    0        7     2     0     2     2     0     8    0
dirhash    1024      43    0       26     3     0     3     3     0     8    0
dino2pl    256     6583    0     5054    96     0    96    96     0     8    0
ffsino     296     6583    0     5054   118     0   118   118     0     8    0
nchpl      144    10295    0     8566    65     0    65    65     0     8    0
rtmask      32       29    0       29     3     3     0     1     0     8    0
uvmvnodes   80     5927    0        0   121     0   121   121     0     8    0
vnodes     216     5927    0        0   330     0   330   330     0     8    0
namei      1024   38273    0    38272     2     1     1     2     0     8    0
percpumem   16      241    0      191     1     0     1     1     0     8    0
kstatmem   264      232    0      202     6     3     3     3     0     8    1
scsiplug    72       13    0       13     6     5     1     1     0     8    1
scxspl     216    66498    0    66498    16    14     2     8     1     8    2
plimitpl   152      538    0      521     1     0     1     1     0     8    0
sigapl     424     3102    0     3044     9     1     8     9     0     8    0
knotepl    120      635    0        0    19     0    19    19     0     8    0
kqueuepl   224      990    0      981    11     9     2     5     0     8    1
pipepl     344      487    0      460     9     6     3     9     0     8    0
fdescpl    528     3053    0     3019     3     0     3     3     0     8    0
filepl     160    22004    0    21779    33    19    14    21     0     8    1
lockfpl    104     1485    0     1483     4     2     2     2     0     8    1
lockfspl    48      545    0      543     1     0     1     1     0     8    0
sessionpl  144       43    0       32     1     0     1     1     0     8    0
pgrppl      48       97    0       78     1     0     1     1     0     8    0
ucredpl    104     3754    0     3739     1     0     1     1     0     8    0
zombiepl   144     4299    0     4298     1     0     1     1     0     8    0
processpl  1248    3102    0     3044     6     0     6     6     0     8    0
procpl     664     7428    0     7366     9     2     7     8     0     8    0
sosppl     168       27    0       26     6     5     1     1     0     8    0
sockpl     752     6101    0     6058    55    47     8    18     0     8    2
mcl64k     65536     17    0        0     3     0     3     3     0     8    0
mcl16k     16384      4    0        0     1     0     1     1     0     8    0
mcl12k     12288      2    0        0     1     0     1     1     0     8    0
mcl9k      9216       1    0        0     1     0     1     1     0     8    0
mcl8k      8192       3    0        0     1     0     1     1     0     8    0
mcl4k      4096     112    0        0    14     0    14    14     0     8    0
mcl2k2     2112       1    0        0     1     0     1     1     0     8    0
mcl2k      2048      57    0        0     6     0     6     6     0     8    0
mtagpl      96       20    0        0     1     0     1     1     0     8    0
mbufpl     256     1573    0        0    97     0    97    97     0     8    0
bufpl      280    28659    0    22516   441     1   440   440     0     8    0
anonpl      32    12063    0        0    98     0    98    98     0   246    0
amapchunkpl 152   92043    0    91609    60    31    29    34     0   158    8
amappl16   200     9812    0     9778    43    31    12    22     0     8    2
amappl15   192        4    0        4     2     2     0     1     0     8    0
amappl14   184      158    0      144     1     0     1     1     0     8    0
amappl13   176       12    0       12     2     2     0     1     0     8    0
amappl12   168     3929    0     3896     4     2     2     3     0     8    0
amappl11   160       49    0       35     1     0     1     1     0     8    0
amappl10   152        3    0        3     1     1     0     1     0     8    0
amappl9    144      259    0      259     1     1     0     1     0     8    0
amappl8    136       23    0       20     1     0     1     1     0     8    0
amappl7    128      143    0      128     1     0     1     1     0     8    0
amappl6    120      325    0      318     1     0     1     1     0     8    0
amappl5    112      181    0      171     1     0     1     1     0     8    0
amappl4    104      349    0      327     1     0     1     1     0     8    0
amappl3     96    18816    0    18713     6     2     4     4     0     8    0
amappl2     88      896    0      819     2     0     2     2     0     8    0
amappl1     80    20909    0    20138    20     3    17    17     0     8    0
amappl      88    25720    0    25568     5     0     5     5     0    92    0
dma65536   65536      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     1     0     1     0     8    0
dma256     256        8    0        8     3     3     0     1     0     8    0
dma128     128      254    0      254     2     1     1     1     0     8    1
dma64       64        7    0        7     2     2     0     1     0     8    0
dma32       32        8    0        8     2     2     0     1     0     8    0
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72       61    0        7     1     0     1     1     0     8    0
uaddrrnd    24     3053    0     3019     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     3053    0     3019     1     0     1     1     0     8    0
vmmpekpl   168    24300    0    24254     3     0     3     3     0     8    0
vmmpepl    168   194345    0   192093   129    22   107   112     0   357    4
vmsppl     488     3052    0     3019     6     1     5     5     0     8    0
rwobjpl     80    56557    0    49448   152     2   150   151     0     8    1
pdppl      4096    6114    0     6038   130    52    78    88     0     8    2
pvpl        32    19715    0        0   159     0   159   159     0   265    0
pmappl     256     3052    0     3019     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      420    0       85    10     0    10    10     0     8    0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
icmp_mtudisc_timeout(fffffd806b6790c0,0) at icmp_mtudisc_timeout+0x123 sys/netinet/ip_icmp.c:1102
rt_timer_queue_flush(ffffffff839813a8) at rt_timer_queue_flush+0x28d sys/net/route.c:1586
ip_sysctl(ffff80002a346eac,1,0,ffff80002a346ed8,200000001300,4) at ip_sysctl+0x84d sys/netinet/ip_input.c:1750
net_sysctl(ffff80002a346ea4,3,0,ffff80002a346ed8,200000001300,4,4fc51ea41072f126) at net_sysctl+0x64e sys/kern/uipc_domain.c:260
sys_sysctl(ffff80002a322fd0,ffff80002a347010,ffff80002a346f60) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80002a347010) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a347010) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:748
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x551d5d2cc00, count: -7
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
end of kernel
end trace frame: 0x7a5b87cadcf0, count: -3

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/12 02:52 openbsd 3ae9e49f3bd9 c06e8995 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore protection_fault: icmp_mtudisc_timeout
2025/08/02 09:15 openbsd 4c5c4401a4d8 3cda49cf .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main protection_fault: icmp_mtudisc_timeout
2025/07/27 17:55 openbsd 7b0d12c26b01 3cda49cf .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main protection_fault: icmp_mtudisc_timeout
2025/07/25 17:22 openbsd c5645c128364 3cda49cf .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main protection_fault: icmp_mtudisc_timeout
2025/07/16 23:23 openbsd 9ce74a582983 3cda49cf .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore protection_fault: icmp_mtudisc_timeout
* Struck through repros no longer work on HEAD.