syzbot


panic: free: size too small 24 <= 256 / 2 (ADDR) type in_multi

Status: auto-closed as invalid on 2020/01/10 07:01
Reported-by: syzbot+d77aa43f13941058b685@syzkaller.appspotmail.com
First crash: 1867d, last: 1867d

Sample crash report:
panic: free: size too small 24 <= 256 / 2 (0xffff800000b067e8) type in_multi
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
free(ffff800000b067e8,36,18) at free+0x54c
in6_purgeaddr(ffff800000ad4500) at in6_purgeaddr+0x1b7 sys/netinet6/in6.c:913
in6_ifdetach(ffff800000a75000) at in6_ifdetach+0x74 sys/netinet6/in6_ifattach.c:422
if_detach(ffff800000a75000) at if_detach+0x155 sys/net/if.c:1110
tun_clone_destroy(ffff800000a75000) at tun_clone_destroy+0x1c0 sys/net/if_tun.c:278
spec_close(ffff80001653ddb0) at spec_close+0x3b0 sys/kern/spec_vnops.c:553
VOP_CLOSE(fffffd80365a38f0,7,fffffd803f7c6ba0,ffff8000ffff89e8) at VOP_CLOSE+0xc0 sys/kern/vfs_vops.c:175
vn_closefile(fffffd802de93cb8,ffff8000ffff89e8) at vn_closefile+0xd3 vn_close sys/kern/vfs_vnops.c:301 [inline]
vn_closefile(fffffd802de93cb8,ffff8000ffff89e8) at vn_closefile+0xd3 sys/kern/vfs_vnops.c:613
fdrop(fffffd802de93cb8,ffff8000ffff89e8) at fdrop+0xc2 sys/kern/kern_descrip.c:1273
closef(fffffd802de93cb8,ffff8000ffff89e8) at closef+0x118 sys/kern/kern_descrip.c:1257
fdfree(ffff8000ffff89e8) at fdfree+0x100 sys/kern/kern_descrip.c:1189
exit1(ffff8000ffff89e8,19,1) at exit1+0x32f sys/kern/kern_exit.c:196
end trace frame: 0xffff80001653e100, 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
free: size too small 24 <= 256 / 2 (0xffff800000b067e8) type in_multi
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
free(ffff800000b067e8,36,18) at free+0x54c
in6_purgeaddr(ffff800000ad4500) at in6_purgeaddr+0x1b7 sys/netinet6/in6.c:913
in6_ifdetach(ffff800000a75000) at in6_ifdetach+0x74 sys/netinet6/in6_ifattach.c:422
if_detach(ffff800000a75000) at if_detach+0x155 sys/net/if.c:1110
tun_clone_destroy(ffff800000a75000) at tun_clone_destroy+0x1c0 sys/net/if_tun.c:278
spec_close(ffff80001653ddb0) at spec_close+0x3b0 sys/kern/spec_vnops.c:553
VOP_CLOSE(fffffd80365a38f0,7,fffffd803f7c6ba0,ffff8000ffff89e8) at VOP_CLOSE+0xc0 sys/kern/vfs_vops.c:175
vn_closefile(fffffd802de93cb8,ffff8000ffff89e8) at vn_closefile+0xd3 vn_close sys/kern/vfs_vnops.c:301 [inline]
vn_closefile(fffffd802de93cb8,ffff8000ffff89e8) at vn_closefile+0xd3 sys/kern/vfs_vnops.c:613
fdrop(fffffd802de93cb8,ffff8000ffff89e8) at fdrop+0xc2 sys/kern/kern_descrip.c:1273
closef(fffffd802de93cb8,ffff8000ffff89e8) at closef+0x118 sys/kern/kern_descrip.c:1257
fdfree(ffff8000ffff89e8) at fdfree+0x100 sys/kern/kern_descrip.c:1189
exit1(ffff8000ffff89e8,19,1) at exit1+0x32f sys/kern/kern_exit.c:196
postsig(ffff8000ffff89e8,19) at postsig+0x4a6 sigexit sys/kern/kern_sig.c:1499 [inline]
postsig(ffff8000ffff89e8,19) at postsig+0x4a6 sys/kern/kern_sig.c:1431
userret(ffff8000ffff89e8) at userret+0x159 sys/kern/kern_sig.c:1889
Xsyscall(6,38,7f7ffffcebd0,3,0,67e0507a000) at Xsyscall+0x156
end of kernel
end trace frame: 0x7f7ffffcebc0, count: -17
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80001653da50
rbx               0xffff80001653db00
rdx                              0x2
rcx                                0
rax                                0
r8                0xffff80001653da10
r9                               0x1
r10                                0
r11               0x4d72e25e86620980
r12                     0x3000000008
r13               0xffff80001653da60
r14                            0x100
r15                              0x1
rip               0xffffffff81878d48    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff80001653da40
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor.0) pid=57824 stat=onproc
    flags process=a<EXEC,EXITING> proc=2000<WEXIT>
    pri=17, usrpri=78, nice=20
    forw=0xffffffffffffffff, list=0xffff8000ffff93c8,0xffff8000ffff5658
    process=0xffff8000148a2a38 user=0xffff800016539000, vmspace=0xfffffd803f014000
    estcpu=28, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 94786  163048   1472      0  2         0x2                syz-executor.1
  3875  356581      0      0  3     0x14200  acct          acct
   921   93914      0      0  3     0x14200  bored         sosplice
  1472  459902  60157      0  3        0x82  thrsleep      syz-fuzzer
  1472  280627  60157      0  3   0x4000082  nanosleep     syz-fuzzer
  1472   60454  60157      0  2   0x4000082                syz-fuzzer
  1472  434517  60157      0  3   0x4000082  thrsleep      syz-fuzzer
  1472  165355  60157      0  3   0x4000082  thrsleep      syz-fuzzer
  1472  342708  60157      0  3   0x4000082  thrsleep      syz-fuzzer
  1472   38055  60157      0  3   0x4000082  thrsleep      syz-fuzzer
 60157  256245  45101      0  3    0x10008a  pause         ksh
 45101  120596  67840      0  3        0x92  select        sshd
 35768  144160      1      0  3    0x100083  ttyin         getty
 67840  153936      1      0  3        0x80  select        sshd
 94435  264288  78621     73  3    0x100090  kqread        syslogd
 78621  314512      1      0  3    0x100082  netio         syslogd
 10450   15222      1     77  2    0x100090                dhclient
 97397   95766      1      0  3        0x80  poll          dhclient
 55943  385882      0      0  2     0x14200                zerothread
  4029  183268      0      0  3     0x14200  aiodoned      aiodoned
 33571  479297      0      0  3     0x14200  syncer        update
 40630  426923      0      0  3     0x14200  cleaner       cleaner
 66597  324091      0      0  3     0x14200  reaper        reaper
 39816  352101      0      0  3     0x14200  pgdaemon      pagedaemon
 91594  167358      0      0  3     0x14200  bored         crynlk
 52945  436200      0      0  3     0x14200  bored         crypto
 82782  504608      0      0  3  0x40014200  acpi0         acpi0
 36313   37249      0      0  2     0x14200                softnet
 76218  448742      0      0  2     0x14200                systqmp
 26445  117137      0      0  3     0x14200  bored         systq
 17298  453197      0      0  3  0x40014200  bored         softclock
 82197  351250      0      0  3  0x40014200                idle0
 52543  523600      0      0  3     0x14200  bored         smr
     1  148139      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim Kern Lim
         devbuf  9533   6351K    7493K  78643K     12690        0        0
            pcb    13      9K       9K  78643K       364        0        0
         rtable    75      3K       4K  78643K       628        0        0
         ifaddr    63     13K      13K  78643K       100        0        0
       counters    19     16K      16K  78643K        19        0        0
       ioctlops     0      0K       2K  78643K        83        0        0
            iov     0      0K      24K  78643K       191        0        0
          mount     1      1K       1K  78643K         1        0        0
         vnodes  1228     77K      77K  78643K      2032        0        0
      UFS quota     1     32K      32K  78643K         1        0        0
      UFS mount     5     36K      36K  78643K         5        0        0
            shm     2      1K       5K  78643K        12        0        0
         VM map     8      2K       2K  78643K        11        0        0
            sem    12      0K       1K  78643K       251        0        0
        dirhash    12      2K       2K  78643K        12        0        0
           ACPI  1793    195K     288K  78643K     12645        0        0
      file desc     4      9K      25K  78643K       844        0        0
          sigio     0      0K       0K  78643K        19        0        0
           proc    49     38K      63K  78643K       481        0        0
        subproc    23      1K       2K  78643K        68        0        0
    NFS srvsock     1      0K       0K  78643K         1        0        0
     NFS daemon     1     16K      16K  78643K         1        0        0
    ip_moptions     0      0K       0K  78643K        41        0        0
       in_multi    12      0K       2K  78643K        63        0        0
    ether_multi     1      0K       0K  78643K         3        0        0
            mrt     0      0K       0K  78643K         4        0        0
    ISOFS mount     1     32K      32K  78643K         1        0        0
  MSDOSFS mount     1     16K      16K  78643K         1        0        0
           ttys    84    371K     371K  78643K        84        0        0
           exec     0      0K       1K  78643K       306        0        0
     pfkey data     0      0K       4K  78643K         2        0        0
        pagedep     1      8K       8K  78643K         1        0        0
       inodedep     1     32K      32K  78643K         1        0        0
         newblk     1      0K       0K  78643K         1        0        0
        VM swap     7     26K      26K  78643K         7        0        0
       UVM amap   116     71K      71K  78643K      2903        0        0
       UVM aobj   104      3K       3K  78643K       108        0        0
        memdesc     1      4K       4K  78643K         1        0        0
    crypto data     1      1K       1K  78643K         1        0        0
    ip6_options     0      0K       0K  78643K       116        0        0
            NDP    15      0K       0K  78643K        29        0        0
           temp   197   3540K    3608K  78643K     36267        0        0
         kqueue     0      0K       0K  78643K         6        0        0
      SYN cache     2     16K      16K  78643K         2        0        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64       17    0       14     1     0     1     1     0     8    0
rtpcb       80      107    0      105     1     0     1     1     0     8    0
rtentry    112       98    0       72     2     0     2     2     0     8    0
unpcb      120      458    0      450     1     0     1     1     0     8    0
syncache   264       13    0       13     3     3     0     1     0     8    0
tcpqe       32      277    0      277     2     2     0     1     0     8    0
tcpcb      544      317    0      312     4     3     1     2     0     8    0
ipq         40       11    0       11     3     2     1     1     0     8    1
ipqe        40      157    0      157     3     2     1     1     0     8    1
inpcb      280     2543    0     2535     5     3     2     4     0     8    1
rttmr       72        2    0        2     1     1     0     1     0     8    0
ip6q        72        1    0        1     1     1     0     1     0     8    0
ip6af       40        3    0        3     1     1     0     1     0     8    0
nd6         48       12    0       11     1     0     1     1     0     8    0
pkpcb       40       10    0       10     3     2     1     1     0     8    1
ppxss      1128       3    0        3     3     2     1     1     0     8    1
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      397    0      201    16     0    16    16     0     8    0
art_table   32      398    0      201     2     0     2     2     0     8    0
art_node    16       97    0       65     1     0     1     1     0     8    0
sysvmsgpl   40       55    0       15     1     0     1     1     0     8    0
semupl     112        3    0        3     1     1     0     1     0     8    0
semapl     112      249    0      239     1     0     1     1     0     8    0
shmpl      112      106    0        4     3     0     3     3     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     2669    0     1278    46     0    46    46     0     8    0
ffsino     240     2669    0     1278    83     0    83    83     0     8    0
nchpl      144     4020    0     2416    60     0    60    60     0     8    0
uvmvnodes   72     3274    0        0    60     0    60    60     0     8    0
vnodes     208     3274    0        0   173     0   173   173     0     8    0
namei      1024   12375    0    12375     1     0     1     1     0     8    1
vcpupl     1984       6    0        0     1     0     1     1     0     8    0
vmpool     520        9    0        3     2     1     1     1     0     8    0
scxspl     192    13019    0    13019    11    10     1     6     0     8    1
plimitpl   152       86    0       79     1     0     1     1     0     8    0
sigapl     432     1009    0      997     2     0     2     2     0     8    0
futexpl     56    23210    0    23210     1     0     1     1     0     8    1
knotepl    112      176    0      157     1     0     1     1     0     8    0
kqueuepl   104      175    0      173     1     0     1     1     0     8    0
pipepl     112      568    0      550     4     3     1     2     0     8    0
fdescpl    424     1010    0      997     2     0     2     2     0     8    0
filepl     120     8775    0     8689     7     2     5     5     0     8    2
lockfpl    104      302    0      301     1     0     1     1     0     8    0
lockfspl    48      101    0      100     1     0     1     1     0     8    0
sessionpl  112       19    0        9     1     0     1     1     0     8    0
pgrppl      48       27    0       17     1     0     1     1     0     8    0
ucredpl     96     1582    0     1575     1     0     1     1     0     8    0
zombiepl   144      998    0      997     1     0     1     1     0     8    0
processpl  864     1026    0      997     4     0     4     4     0     8    0
procpl     632     2091    0     2056     4     0     4     4     0     8    0
sosppl     128       14    0       14     4     3     1     1     0     8    1
sockpl     384     3214    0     3196     9     5     4     7     0     8    2
mcl64k     65536     70    0       70     2     1     1     1     0     8    1
mcl16k     16384     10    0       10     4     3     1     1     0     8    1
mcl12k     12288     19    0       19     3     2     1     1     0     8    1
mcl9k      9216      14    0       14     2     1     1     1     0     8    1
mcl8k      8192      39    0       39     1     0     1     1     0     8    1
mcl4k      4096      92    0       92     2     1     1     1     0     8    1
mcl2k2     2112       8    0        8     5     4     1     1     0     8    1
mcl2k      2048   64213    0    64170    19    12     7    17     0     8    1
mtagpl      80       18    0       18     2     1     1     1     0     8    1
mbufpl     256   108925    0   108827    34    16    18    22     0     8    8
bufpl      256    10237    0     3919   396     0   396   396     0     8    0
anonpl      16   124898    0   107523   108    31    77   100     0    62    2
amapchunkpl 152    4749    0     4617    19    12     7    16     0   158    0
amappl16   192     5915    0     4904    89    33    56    70     0     8    5
amappl15   184        9    0        9     1     1     0     1     0     8    0
amappl14   176       41    0       38     1     0     1     1     0     8    0
amappl13   168      131    0      130     1     0     1     1     0     8    0
amappl12   160      362    0      359     1     0     1     1     0     8    0
amappl11   152       53    0       42     1     0     1     1     0     8    0
amappl10   144      107    0      104     1     0     1     1     0     8    0
amappl9    136      830    0      821     1     0     1     1     0     8    0
amappl8    128      401    0      369     2     0     2     2     0     8    0
amappl7    120      132    0      126     1     0     1     1     0     8    0
amappl6    112       68    0       58     1     0     1     1     0     8    0
amappl5    104      517    0      507     1     0     1     1     0     8    0
amappl4     96     1352    0     1328     1     0     1     1     0     8    0
amappl3     88      146    0      141     1     0     1     1     0     8    0
amappl2     80     7196    0     7140     3     1     2     3     0     8    0
amappl1     72    26811    0    26413    26    17     9    20     0     8    0
amappl      80     2352    0     2307     2     0     2     2     0    84    0
dma4096    4096       1    0        1     1     1     0     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       17    0       17     1     1     0     1     0     8    0
aobjpl      64      107    0        4     2     0     2     2     0     8    0
uaddrrnd    24     1019    0      997     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1019    0      997     1     0     1     1     0     8    0
vmmpekpl   168    10047    0    10017     2     0     2     2     0     8    0
vmmpepl    168   128361    0   126385   165    46   119   130     0   357   25
vmsppl     272     1009    0      997     2     1     1     2     0     8    0
pdppl      4096    2044    0     2006     7     1     6     6     0     8    0
pvpl        32   374821    0   354479   259    48   211   241     0   265   37
pmappl     200     1018    0     1000     2     0     2     2     0     8    1
extentpl    40       41    0       26     1     0     1     1     0     8    0
phpool     112      577    0       40    16     0    16    16     0     8    0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/12 07:01 openbsd 353d046454df 426631dd .config console log report ci-openbsd-main
* Struck through repros no longer work on HEAD.