syzbot


panic: Data modified on freelist: word 5 of object ADDR size 0xc0 previous type devbuf (0xd != ADDR)

Status: closed as invalid on 2019/10/13 14:21
Reported-by: syzbot+87cf028c6bb237002fe4@syzkaller.appspotmail.com
First crash: 1874d, last: 1874d

Sample crash report:
panic: Data modified on freelist: word 5 of object 0xffff800000a8bd00 size 0xc0 previous type devbuf (0xd != 0xdeaf4152)

Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
* 39811  37138      0           0          0    0  dhclient
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
malloc(c0,5,9) at malloc+0xa23 sys/kern/kern_malloc.c:331
rtm_report(fffffd8036d71070,4,d886e631,0) at rtm_report+0x2d9 sys/net/rtsock.c:654
route_output(fffffd802f594d00,fffffd803a01b180,0,0) at route_output+0x6b7 sys/net/rtsock.c:824
route_usrreq(fffffd803a01b180,9,fffffd802f594d00,0,0,ffff8000ffff8ed8) at route_usrreq+0x363 sys/net/rtsock.c:275
sosend(fffffd803a01b180,0,ffff800014886440,0,0,0) at sosend+0x63d sys/kern/uipc_socket.c:524
dofilewritev(ffff8000ffff8ed8,6,ffff800014886440,0,ffff800014886530) at dofilewritev+0x1ac sys/kern/sys_generic.c:364
sys_writev(ffff8000ffff8ed8,ffff8000148864e0,ffff800014886530) at sys_writev+0xa7 sys/kern/sys_generic.c:311
syscall(ffff8000148865b0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555
Xsyscall(6,79,0,79,d886e631,77ed60ba000) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffdaef0, count: 4
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
Data modified on freelist: word 5 of object 0xffff800000a8bd00 size 0xc0 previous type devbuf (0xd != 0xdeaf4152)

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
malloc(c0,5,9) at malloc+0xa23 sys/kern/kern_malloc.c:331
rtm_report(fffffd8036d71070,4,d886e631,0) at rtm_report+0x2d9 sys/net/rtsock.c:654
route_output(fffffd802f594d00,fffffd803a01b180,0,0) at route_output+0x6b7 sys/net/rtsock.c:824
route_usrreq(fffffd803a01b180,9,fffffd802f594d00,0,0,ffff8000ffff8ed8) at route_usrreq+0x363 sys/net/rtsock.c:275
sosend(fffffd803a01b180,0,ffff800014886440,0,0,0) at sosend+0x63d sys/kern/uipc_socket.c:524
dofilewritev(ffff8000ffff8ed8,6,ffff800014886440,0,ffff800014886530) at dofilewritev+0x1ac sys/kern/sys_generic.c:364
sys_writev(ffff8000ffff8ed8,ffff8000148864e0,ffff800014886530) at sys_writev+0xa7 sys/kern/sys_generic.c:311
syscall(ffff8000148865b0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555
Xsyscall(6,79,0,79,d886e631,77ed60ba000) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffdaef0, count: -11
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff800014885d50
rbx               0xffff800014885e00
rdx                              0x2
rcx                                0
rax                                0
r8                0xffff800014885d10
r9                               0x1
r10                                0
r11               0xc0495391444d3ba1
r12                     0x3000000008
r13               0xffff800014885d60
r14                            0x100
r15                              0x1
rip               0xffffffff820d0728    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff800014885d40
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb> show proc
PROC (dhclient) pid=39811 stat=onproc
    flags process=0 proc=0
    pri=50, usrpri=50, nice=20
    forw=0xffffffffffffffff, list=0xffff8000ffff8280,0xffff8000ffff93d8
    process=0xffff8000ffff6d90 user=0xffff800014881000, vmspace=0xfffffd803f013000
    estcpu=0, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 41464  244764  98424      0  3        0x80  nanosleep     syz-executor.1
 41464  498126  98424      0  3   0x4000080  kqread        syz-executor.1
 41464  438878  98424      0  3   0x4000080  fsleep        syz-executor.1
 98424   61734  82163      0  3        0x82  nanosleep     syz-executor.1
 45786  135627      0      0  3     0x14200  bored         sosplice
 78259    5544  82163      0  3        0x82  nanosleep     syz-executor.0
 82163  202603  66700      0  3        0x82  thrsleep      syz-fuzzer
 82163  271375  66700      0  3   0x4000082  thrsleep      syz-fuzzer
 82163  339356  66700      0  3   0x4000082  kqread        syz-fuzzer
 82163  266355  66700      0  3   0x4000082  thrsleep      syz-fuzzer
 82163   16261  66700      0  3   0x4000082  thrsleep      syz-fuzzer
 82163  269192  66700      0  3   0x4000082  thrsleep      syz-fuzzer
 82163  427554  66700      0  3   0x4000082  thrsleep      syz-fuzzer
 82163  483811  66700      0  3   0x4000082  thrsleep      syz-fuzzer
 66700  216092  81294      0  3    0x10008a  pause         ksh
 81294   13600  67671      0  3        0x92  select        sshd
 91131  183036      1      0  3    0x100083  ttyin         getty
 67671  489448      1      0  3        0x80  select        sshd
 11740  177326  91732     73  3    0x100090  kqread        syslogd
 91732  404402      1      0  3    0x100082  netio         syslogd
 48998  134819      1     77  2    0x100010                dhclient
*37138   39811      1      0  7           0                dhclient
 64871  438537      0      0  2     0x14200                zerothread
 69314  183950      0      0  3     0x14200  aiodoned      aiodoned
  6069  170668      0      0  3     0x14200  syncer        update
 28694  150033      0      0  3     0x14200  cleaner       cleaner
 18176  344907      0      0  3     0x14200  reaper        reaper
 66716   87118      0      0  3     0x14200  pgdaemon      pagedaemon
 83111  168862      0      0  3     0x14200  bored         crynlk
 46055  112251      0      0  3     0x14200  bored         crypto
 68628  357077      0      0  3  0x40014200  acpi0         acpi0
  5901  363800      0      0  2     0x14200                softnet
 78990   87533      0      0  3     0x14200  bored         systqmp
 75668   86757      0      0  3     0x14200  bored         systq
 44110  271302      0      0  3  0x40014200  bored         softclock
 31914  151239      0      0  3  0x40014200                idle0
 47852  146826      0      0  3     0x14200  bored         smr
     1  308989      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  9490   6390K    6974K  78643K     11011        0        0
            pcb    13      8K       8K  78643K        54        0        0
         rtable    91      7K       8K  78643K       316        0        0
         ifaddr    48     11K      12K  78643K        76        0        0
       counters    19     16K      16K  78643K        19        0        0
       ioctlops     0      0K       2K  78643K        21        0        0
            iov     0      0K      16K  78643K        37        0        0
          mount     1      1K       1K  78643K         1        0        0
         vnodes  1219     77K      77K  78643K      1414        0        0
      UFS quota     1     32K      32K  78643K         1        0        0
      UFS mount     5     36K      36K  78643K         5        0        0
            shm     2      1K       1K  78643K         2        0        0
         VM map     2      0K       0K  78643K         2        0        0
            sem    12      0K       1K  78643K        25        0        0
        dirhash    12      2K       2K  78643K        12        0        0
           ACPI  1793    195K     288K  78643K     12645        0        0
      file desc     6     17K      25K  78643K       188        0        0
          sigio     0      0K       0K  78643K         4        0        0
           proc    48     38K      63K  78643K       393        0        0
        subproc    32      2K       2K  78643K        51        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        16        0        0
       in_multi    22      1K       2K  78643K        45        0        0
    ether_multi     1      0K       0K  78643K         1        0        0
    ISOFS mount     1     32K      32K  78643K         1        0        0
  MSDOSFS mount     1     16K      16K  78643K         1        0        0
           ttys    48    212K     212K  78643K        48        0        0
           exec     0      0K       1K  78643K       219        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    97     21K      22K  78643K      1386        0        0
       UVM aobj     8      2K       2K  78643K         8        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        22        0        0
            NDP    10      0K       0K  78643K        22        0        0
           temp   154   3536K    3608K  78643K      3967        0        0
         kqueue     0      0K       0K  78643K         2        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       11    0        7     1     0     1     1     0     8    0
rtpcb       80       28    0       26     1     0     1     1     0     8    0
rtentry    112       62    0       28     2     0     2     2     0     8    0
unpcb      120      102    0       94     1     0     1     1     0     8    0
syncache   264        4    0        4     1     1     0     1     0     8    0
tcpqe       32     3220    0     3220     1     1     0     1     0     8    0
tcpcb      544       68    0       64     2     1     1     2     0     8    0
inpcb      280      172    0      165     3     2     1     3     0     8    0
nd6         48        6    0        4     1     0     1     1     0     8    0
ppxss      1128       2    0        2     1     1     0     1     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      265    0       93    14     0    14    14     0     8    2
art_table   32      266    0       93     2     0     2     2     0     8    0
art_node    16       61    0       30     1     0     1     1     0     8    0
semupl     112        1    0        1     1     1     0     1     0     8    0
semapl     112       20    0       10     1     0     1     1     0     8    0
shmpl      112        6    0        0     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     1658    0      263    46     0    46    46     0     8    0
ffsino     240     1658    0      263    83     0    83    83     0     8    0
nchpl      144     2114    0      512    60     0    60    60     0     8    0
uvmvnodes   72     1854    0        0    34     0    34    34     0     8    0
vnodes     208     1854    0        0    98     0    98    98     0     8    0
namei      1024    5665    0     5665     3     2     1     1     0     8    1
scxspl     192     5826    0     5826    12    11     1     7     0     8    1
plimitpl   152       24    0       16     1     0     1     1     0     8    0
sigapl     432      356    0      342     2     0     2     2     0     8    0
futexpl     56     4115    0     4114     1     0     1     1     0     8    0
knotepl    112      180    0      160     1     0     1     1     0     8    0
kqueuepl   104      197    0      193     1     0     1     1     0     8    0
pipepl     112      212    0      191     3     2     1     2     0     8    0
fdescpl    424      357    0      342     2     0     2     2     0     8    0
filepl     120     2422    0     2318     5     1     4     5     0     8    0
lockfpl    104       41    0       40     1     0     1     1     0     8    0
lockfspl    48       17    0       16     1     0     1     1     0     8    0
sessionpl  112       18    0        8     1     0     1     1     0     8    0
pgrppl      48       18    0        8     1     0     1     1     0     8    0
ucredpl     96      268    0      261     1     0     1     1     0     8    0
zombiepl   144      343    0      342     3     2     1     1     0     8    0
processpl  864      372    0      342     4     0     4     4     0     8    0
procpl     632      648    0      609     5     1     4     5     0     8    0
sosppl     128        3    0        3     1     1     0     1     0     8    0
sockpl     384      306    0      289     6     3     3     6     0     8    1
mcl64k     65536     20    0       20     2     1     1     1     0     8    1
mcl12k     12288      9    0        9     1     0     1     1     0     8    1
mcl9k      9216       1    0        1     1     1     0     1     0     8    0
mcl8k      8192       5    0        5     2     1     1     1     0     8    1
mcl4k      4096      23    0       23     2     1     1     1     0     8    1
mcl2k2     2112       3    0        3     2     1     1     1     0     8    1
mcl2k      2048   64906    0    64863    15     9     6    13     0     8    0
mtagpl      80        8    0        4     3     2     1     1     0     8    0
mbufpl     256   105102    0   105029    14     6     8    10     0     8    1
bufpl      256     6420    0     1580   303     0   303   303     0     8    0
anonpl      16    58776    0    42604    83     9    74    80     0    62    9
amapchunkpl 152    2019    0     1907    10     5     5     8     0   158    0
amappl16   192     2057    0     1124    53     6    47    53     0     8    0
amappl14   176      102    0       97     2     1     1     1     0     8    0
amappl12   160       81    0       76     1     0     1     1     0     8    0
amappl11   152       51    0       40     1     0     1     1     0     8    0
amappl10   144       22    0       18     1     0     1     1     0     8    0
amappl9    136      585    0      579     1     0     1     1     0     8    0
amappl8    128      155    0      131     1     0     1     1     0     8    0
amappl7    120       39    0       35     1     0     1     1     0     8    0
amappl6    112       67    0       58     1     0     1     1     0     8    0
amappl5    104      228    0      215     1     0     1     1     0     8    0
amappl4     96      538    0      510     1     0     1     1     0     8    0
amappl3     88      157    0      151     1     0     1     1     0     8    0
amappl2     80     1965    0     1891     4     2     2     3     0     8    0
amappl1     72    16632    0    16217    28    19     9    20     0     8    0
amappl      80      903    0      864     2     1     1     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        7    0        0     1     0     1     1     0     8    0
uaddrrnd    24      357    0      342     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      357    0      342     1     0     1     1     0     8    0
vmmpekpl   168     6881    0     6857     2     0     2     2     0     8    0
vmmpepl    168    51046    0    48972   158    40   118   123     0   357   26
vmsppl     272      356    0      342     3     2     1     2     0     8    0
pdppl      4096     720    0      684     6     1     5     6     0     8    0
pvpl        32   177618    0   158374   199    17   182   188     0   265   26
pmappl     200      356    0      342     1     0     1     1     0     8    0
extentpl    40       41    0       26     1     0     1     1     0     8    0
phpool     112      455    0       26    13     0    13    13     0     8    0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/05 17:23 openbsd 2b2159bad083 f3f7d9c8 .config console log report ci-openbsd-main
* Struck through repros no longer work on HEAD.