syzbot


panic: free: size too large NUM > NUM (ADDR) type rtable

Status: upstream: reported on 2026/07/15 15:02
Reported-by: syzbot+064084701f73ec75ad93@syzkaller.appspotmail.com
First crash: 4d16h, last: 2d01h

Sample crash report:
panic: free: size too large 100 > 16 (0xffff800000c57c40) type rtable
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834c06a2) at panic+0x1cf sys/kern/subr_prf.c:198
free(ffff800000c57c40,5,64) at free+0x690 sys/kern/kern_malloc.c:387
rtfree(fffff3800df8b1a0) at rtfree+0x34e sys/net/route.c:646
rt_ifa_dellocal(ffff800001603c00) at rt_ifa_dellocal+0x1ea sys/net/route.c:1452
in_purgeaddr(ffff800001603c00) at in_purgeaddr+0x1c5 sys/netinet/in.c:754
in_ifdetach(ffff8000015f4800) at in_ifdetach+0x7e sys/netinet/in.c:1015
if_detach(ffff8000015f4800) at if_detach+0x322 sys/net/if.c:1311
tun_clone_destroy(ffff8000015f4800) at tun_clone_destroy+0x2a2 sys/net/if_tun.c:343
if_clone_destroy(ffff80002a885910) at if_clone_destroy+0x1d5 sys/net/if.c:1479
tun_dev_close(5d06,7) at tun_dev_close+0x1d9 sys/net/if_tun.c:526
spec_close(ffff80002a8859d0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffff3806fb68898,7,fffff38007ffd548,ffff80002a736f98) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621
end trace frame: 0xffff80002a885af0, count: 0
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: free: size too large 100 > 16 (0xffff800000c57c40) type rtable
ddb> show kasan
No such command
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834c06a2) at panic+0x1cf sys/kern/subr_prf.c:198
free(ffff800000c57c40,5,64) at free+0x690 sys/kern/kern_malloc.c:387
rtfree(fffff3800df8b1a0) at rtfree+0x34e sys/net/route.c:646
rt_ifa_dellocal(ffff800001603c00) at rt_ifa_dellocal+0x1ea sys/net/route.c:1452
in_purgeaddr(ffff800001603c00) at in_purgeaddr+0x1c5 sys/netinet/in.c:754
in_ifdetach(ffff8000015f4800) at in_ifdetach+0x7e sys/netinet/in.c:1015
if_detach(ffff8000015f4800) at if_detach+0x322 sys/net/if.c:1311
tun_clone_destroy(ffff8000015f4800) at tun_clone_destroy+0x2a2 sys/net/if_tun.c:343
if_clone_destroy(ffff80002a885910) at if_clone_destroy+0x1d5 sys/net/if.c:1479
tun_dev_close(5d06,7) at tun_dev_close+0x1d9 sys/net/if_tun.c:526
spec_close(ffff80002a8859d0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffff3806fb68898,7,fffff38007ffd548,ffff80002a736f98) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621
fdrop(fffff3807c1e79e8,ffff80002a736f98) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffff3807c1e79e8,ffff80002a736f98) at closef+0x190 sys/kern/kern_descrip.c:1265
fdfree(ffff80002a736f98) at fdfree+0x115 sys/kern/kern_descrip.c:1196
exit1(ffff80002a736f98,1,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80002a736f98,ffff80002a885d30,ffff80002a885c80) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a885d30) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a885d30) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7558aa1ebbc0, count: -21
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80002a885590
rbx                             0x10
rdx                                0
rcx                                0
rax               0xffff80002a736f98
r8                 0x101010101010101
r9                0x8080808080808080
r10               0x5db9692a918d81f8
r11               0x993e4331ea8f93f0
r12                                0
r13                             0x64
r14                                0
r15                              0x1
rip               0xffffffff832a51f5    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80002a885580
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor) tid=249751 pid=16071 tcnt=0 stat=onproc
    flags process=a<EXEC,EXITING> proc=2000<WEXIT>
    runpri=32, usrpri=51, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=1
    forw=0xffffffffffffffff, list=0xffff80002a737c90,0xffff80002a7362b0
    process=0xffff80002a79ed10 user=0xffff80002a880000, vmspace=0xfffff3807c2745c8
    estcpu=1, cpticks=2, pctcpu=0.0, user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID   UID  S      PRLAGS     PFLAGS WAIT      COMMAND
 34674  370881  10911     0  4      0x2000    0x80000           syz-executor
 34674  204108  10911     0  4      0x2000  0x4080000           syz-executor
 34674  407159  10911     0  2      0x2000  0x4080000           syz-executor
 34674  250551  10911     0  4      0x2000  0x4080000           syz-executor
 34674   98920  10911     0  4      0x2000  0x4080000           syz-executor
 34674  192567  10911     0  3      0x2000  0x4000000 suspend   syz-executor
  4425   82753  18193     0  2           0          0           syz-executor
  4425  308381  18193     0  3           0  0x4000080 msgwait   syz-executor
  4425  266701  18193     0  3           0  0x4000080 msgwait   syz-executor
 37713  221598  98137     0  3         0x2       0x80 nanoslp   syz-executor
 10911     777  98137     0  3         0x2       0x80 nanoslp   syz-executor
 18193  490353  98137     0  3         0x2       0x80 nanoslp   syz-executor
 98137  319656  29710     0  3         0x2       0x80 wait      syz-executor
 29710   57181  13642     0  3    0x100002       0x88 sigsusp   ksh
 13642  149226   4321     0  3        0x10       0x88 kqread    sshd-session
  4321  438324  56652     0  3        0x12       0x80 kqread    sshd-session
 45310  503149      1     0  3    0x100003       0x80 ttyin     getty
 56652  341644      1     0  3           0       0x88 kqread    sshd
 25984  135380   6273    73  3   0x1100010       0x80 kqread    syslogd
  6273  476498      1     0  3    0x100002       0x80 sbwait    syslogd
 77518  460342      1     0  3    0x100000       0x80 kqread    resolvd
 36004  413035   1612    77  3    0x100012       0x80 kqread    dhcpleased
 63317    2704   1612    77  3    0x100012       0x80 kqread    dhcpleased
  1612   36295      1     0  3           0       0x80 kqread    dhcpleased
 26504  240451      0     0  3     0x14000      0x200 bored     smr
 58664  217035      0     0  2     0x14000      0x200           zerothread
 28462  181284      0     0  3     0x14000      0x200 aiodoned  aiodoned
 58500  470957      0     0  3     0x14000      0x200 syncer    update
 37770  265726      0     0  3     0x14000      0x200 cleaner   cleaner
 61006  461931      0     0  3     0x14000      0x200 reaper    reaper
  2375  317929      0     0  3     0x14000      0x200 pgdaemon  pagedaemon
 39844    1153      0     0  3     0x14000      0x200 bored     viomb
 61868  174312      0     0  3     0x14000 0x40000200 acpi0     acpi0
 58881   56825      0     0  3     0x14000      0x200 bored     softnet0
 75169  317234      0     0  3     0x14000      0x200 smrbar    systqmp
 47385  236793      0     0  3     0x14000      0x200 bored     systq
 33704  484378      0     0  3     0x14000 0x40000200 tmoslp    softclock
 79354  208030      0     0  3     0x14000 0x40000200           idle0
     1   23122      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 11024  12100K   12118K 166960K     12115        0
            pcb    17     12K      12K 166960K        17        0
         rtable   210      5K       6K 166960K       355        0
             pf    28     12K      12K 166960K        30        0
         ifaddr    38      6K       7K 166960K        44        0
        ifgroup    46      2K       2K 166960K        50        0
         sysctl     2      1K       9K 166960K         6        0
       counters    32     17K      17K 166960K        33        0
       ioctlops     0      0K       4K 166960K        36        0
            iov     0      0K       0K 166960K         1        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1291     81K      81K 166960K      1363        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       1K 166960K         2        0
         VM map     2      1K       1K 166960K         2        0
            sem     2      0K       0K 166960K         2        0
        dirhash    12      2K       2K 166960K        12        0
           ACPI  1734    201K     291K 166960K     11964        0
      file desc    12     41K      89K 166960K       147        0
           proc    59     59K      83K 166960K       503        0
        subproc    63      3K       4K 166960K        72        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
       in_multi    88      6K       6K 166960K        99        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K         4        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    43    201K     201K 166960K        43        0
           exec     0      0K       1K 166960K       370        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   185    141K     157K 166960K      3012        0
       UVM aobj     4      2K       2K 166960K         4        0
     pinsyscall    33     66K      91K 166960K      1259        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
            NDP    12      0K       1K 166960K        27        0
           temp    33   9106K    9113K 166960K      4674        0
         kqueue    13     20K      22K 166960K        30        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       39    0       36     1     0     1     1     0     8    0
rtentry    136      111    0       14     4     0     4     4     0     8    0
unpcb      144       42    0       27     1     0     1     1     0     8    0
syncache   336        4    0        4     1     0     1     1     0     8    1
tcpcb      736       12    0        8     1     0     1     1     0     8    0
arp         96       18    0        2     1     0     1     1     0     8    0
ipq         40        1    0        0     1     0     1     1     0     8    0
ipqe        40       65    0       64     1     0     1     1     0     8    0
inpcb      328       66    0       59     1     0     1     1     0     8    0
nd6        112       24    0        3     1     0     1     1     0     8    0
pkpcb       40        1    0        1     1     0     1     1     0     8    1
kcovpl      48        8    0        1     1     0     1     1     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      452    0       44    29     0    29    29     0     8    1
art_table   40      453    0       44     5     0     5     5     0     8    0
art_node    32      111    0       20     1     0     1     1     0     8    0
sysvmsgpl   40        2    0        0     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     1573    0      113    92     0    92    92     0     8    0
ffsino     256     1578    0      118    92     0    92    92     0     8    0
nchpl      144     1794    0       97    64     0    64    64     0     8    0
vnodes     216     1664    0        0    93     0    93    93     0     8    0
namei      1024    5362    0     5362     1     0     1     1     0     8    1
kstatmem   264       23    0        2     2     0     2     2     0     8    0
scxspl     216     5994    0     5994     3     0     3     3     1     8    3
plimitpl   152       32    0       15     1     0     1     1     0     8    0
sigapl     424      445    0      407     6     0     6     6     0     8    1
knotepl    120     2059    0     2014     2     0     2     2     0     8    0
kqueuepl   184       26    0       16     1     0     1     1     0     8    0
pipepl     304      127    0      100     3     0     3     3     0     8    0
fdescpl    448      432    0      408     5     0     5     5     0     8    1
filepl     120     1525    0     1330     7     0     7     7     0     8    0
lockfpl    104       13    0       10     1     0     1     1     0     8    0
lockfspl    48        7    0        4     1     0     1     1     0     8    0
sessionpl  144       23    0       15     1     0     1     1     0     8    0
pgrppl      48       32    0       16     1     0     1     1     0     8    0
ucredpl    104      107    0       96     1     0     1     1     0     8    0
zombiepl   144      413    0      407     1     0     1     1     0     8    0
processpl  1152     445    0      407     4     0     4     4     0     8    0
procpl     664      469    0      424     5     0     5     5     0     8    0
sockpl     552      148    0      123     3     0     3     3     0     8    1
mcl8k      8192       5    0        5     1     0     1     1     0     8    1
mcl4k      4096    2525    0     2472    14     0    14    14     0     8    6
mcl2k      2048     211    0      209     1     0     1     1     0     8    0
mextrefs    64       38    0       38     1     0     1     1     0     8    1
mtagpl      96        4    0        4     1     0     1     1     0     8    1
mbufpl     256     4384    0     4293     9     0     9     9     0     8    1
bufpl      272     2275    0      102   145     0   145   145     0     8    0
anonpl      24    79263    0    76519    20     0    20    20     0   187    2
amapchunkpl 152    7903    0     7542    17     0    17    17     0   158    0
amappl16   200     1116    0     1101     4     0     4     4     0     8    3
amappl15   192        5    0        5     1     0     1     1     0     8    1
amappl14   184      440    0      439     1     0     1     1     0     8    0
amappl13   176      116    0      106     1     0     1     1     0     8    0
amappl12   168      676    0      652     2     0     2     2     0     8    0
amappl11   160        4    0        4     1     0     1     1     0     8    1
amappl10   152       56    0       46     1     0     1     1     0     8    0
amappl9    144      271    0      271     1     0     1     1     0     8    1
amappl8    136      101    0      100     1     0     1     1     0     8    0
amappl7    128      158    0      147     1     0     1     1     0     8    0
amappl6    120      146    0      144     1     0     1     1     0     8    0
amappl5    112       94    0       86     1     0     1     1     0     8    0
amappl4    104      266    0      249     1     0     1     1     0     8    0
amappl3     96     1469    0     1387     3     0     3     3     0     8    0
amappl2     88      528    0      474     2     0     2     2     0     8    0
amappl1     80    10154    0     9633    13     0    13    13     0     8    1
amappl      88     2309    0     2184     4     0     4     4     0    92    0
uvmvnodes   80       96    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
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      432    0      408     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      432    0      408     1     0     1     1     0     8    0
vmmpekpl   168     5534    0     5502     2     0     2     2     0     8    0
vmmpepl    168    36551    0    35043    76     0    76    76     0   357    1
vmsppl     368      431    0      408     4     0     4     4     0     8    1
rwobjpl     40    13560    0    12683    10     0    10    10     0     8    0
pdppl      4096     870    0      816    92    30    62    78     0     8    8
pvpl        32   201328    0   194198    65     0    65    65     0   265    0
pmappl     216      431    0      408     2     0     2     2     0     8    0
extentpl    40       46    0       28     1     0     1     1     0     8    0
phpool     112      494    0       30    14     0    14    14     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834c06a2) at panic+0x1cf sys/kern/subr_prf.c:198
free(ffff800000c57c40,5,64) at free+0x690 sys/kern/kern_malloc.c:387
rtfree(fffff3800df8b1a0) at rtfree+0x34e sys/net/route.c:646
rt_ifa_dellocal(ffff800001603c00) at rt_ifa_dellocal+0x1ea sys/net/route.c:1452
in_purgeaddr(ffff800001603c00) at in_purgeaddr+0x1c5 sys/netinet/in.c:754
in_ifdetach(ffff8000015f4800) at in_ifdetach+0x7e sys/netinet/in.c:1015
if_detach(ffff8000015f4800) at if_detach+0x322 sys/net/if.c:1311
tun_clone_destroy(ffff8000015f4800) at tun_clone_destroy+0x2a2 sys/net/if_tun.c:343
if_clone_destroy(ffff80002a885910) at if_clone_destroy+0x1d5 sys/net/if.c:1479
tun_dev_close(5d06,7) at tun_dev_close+0x1d9 sys/net/if_tun.c:526
spec_close(ffff80002a8859d0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffff3806fb68898,7,fffff38007ffd548,ffff80002a736f98) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621
fdrop(fffff3807c1e79e8,ffff80002a736f98) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffff3807c1e79e8,ffff80002a736f98) at closef+0x190 sys/kern/kern_descrip.c:1265
fdfree(ffff80002a736f98) at fdfree+0x115 sys/kern/kern_descrip.c:1196
exit1(ffff80002a736f98,1,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80002a736f98,ffff80002a885d30,ffff80002a885c80) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a885d30) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a885d30) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7558aa1ebbc0, count: -21
ddb> machine ddbcpu 1
No such command
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834c06a2) at panic+0x1cf sys/kern/subr_prf.c:198
free(ffff800000c57c40,5,64) at free+0x690 sys/kern/kern_malloc.c:387
rtfree(fffff3800df8b1a0) at rtfree+0x34e sys/net/route.c:646
rt_ifa_dellocal(ffff800001603c00) at rt_ifa_dellocal+0x1ea sys/net/route.c:1452
in_purgeaddr(ffff800001603c00) at in_purgeaddr+0x1c5 sys/netinet/in.c:754
in_ifdetach(ffff8000015f4800) at in_ifdetach+0x7e sys/netinet/in.c:1015
if_detach(ffff8000015f4800) at if_detach+0x322 sys/net/if.c:1311
tun_clone_destroy(ffff8000015f4800) at tun_clone_destroy+0x2a2 sys/net/if_tun.c:343
if_clone_destroy(ffff80002a885910) at if_clone_destroy+0x1d5 sys/net/if.c:1479
tun_dev_close(5d06,7) at tun_dev_close+0x1d9 sys/net/if_tun.c:526
spec_close(ffff80002a8859d0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffff3806fb68898,7,fffff38007ffd548,ffff80002a736f98) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffff3807c1e79e8,ffff80002a736f98) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621
fdrop(fffff3807c1e79e8,ffff80002a736f98) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffff3807c1e79e8,ffff80002a736f98) at closef+0x190 sys/kern/kern_descrip.c:1265
fdfree(ffff80002a736f98) at fdfree+0x115 sys/kern/kern_descrip.c:1196
exit1(ffff80002a736f98,1,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80002a736f98,ffff80002a885d30,ffff80002a885c80) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a885d30) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a885d30) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7558aa1ebbc0, count: -21

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/18 05:25 openbsd 97f4e10dc0be 72524a66 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main panic: free: size too large NUM > NUM (ADDR) type rtable
2026/07/15 19:52 openbsd af68cf7bb0f1 a4ed0f4f .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-setuid panic: free: size too large NUM > NUM (ADDR) type rtable
2026/07/15 15:01 openbsd af68cf7bb0f1 a4ed0f4f .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main panic: free: size too large NUM > NUM (ADDR) type rtable
* Struck through repros no longer work on HEAD.