syzbot


panic: pool_p_free: mbufpl free list modified: page ADDR; item addr ADDR; offset 0x0=0x0

Status: closed as dup on 2019/12/09 09:34
Reported-by: syzbot+6980ff29287b4cd0ee4e@syzkaller.appspotmail.com
First crash: 1810d, last: 1810d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
pool: free list modified: mbufpl syz 13 2165d 2179d

Sample crash report:
panic: pool_p_free: mbufpl free list modified: page 0xfffffd802d6db000; item addr 0xfffffd802d6db000; offset 0x0=0x0
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*197063  72445      0     0x14000      0x200    0  systqmp
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic(ffffffff821fd447) at panic+0x15c sys/kern/subr_prf.c:207
pool_p_free(ffffffff82563c50,fffffd802d7a3b80) at pool_p_free+0x1de sys/kern/subr_pool.c:991
pool_gc_pages(0) at pool_gc_pages+0x225 sys/kern/subr_pool.c:1586
taskq_thread(ffffffff824771f0) at taskq_thread+0x52 sys/kern/kern_task.c:369
end trace frame: 0x0, count: 10
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
pool_p_free: mbufpl free list modified: page 0xfffffd802d6db000; item addr 0xfffffd802d6db000; offset 0x0=0x0
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic(ffffffff821fd447) at panic+0x15c sys/kern/subr_prf.c:207
pool_p_free(ffffffff82563c50,fffffd802d7a3b80) at pool_p_free+0x1de sys/kern/subr_pool.c:991
pool_gc_pages(0) at pool_gc_pages+0x225 sys/kern/subr_pool.c:1586
taskq_thread(ffffffff824771f0) at taskq_thread+0x52 sys/kern/kern_task.c:369
end trace frame: 0x0, count: -5
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80001482e760
rbx               0xffff80001482e810
rdx                              0x2
rcx                                0
rax                                0
r8                0xffff80001482e720
r9                               0x1
r10                                0
r11               0x932f7961ae9c2ec4
r12                     0x3000000008
r13               0xffff80001482e770
r14                            0x100
r15                              0x1
rip               0xffffffff817e9708    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff80001482e750
ss                                 0
db_enter+0x18:  addq    $0x8,%rsp
ddb> show proc
PROC (systqmp) pid=197063 stat=onproc
    flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>
    pri=32, usrpri=51, nice=20
    forw=0xffffffffffffffff, list=0xffff8000ffffec58,0xffff8000ffffe288
    process=0xffff8000ffffcd80 user=0xffff800014829000, vmspace=0xffffffff82578d90
    estcpu=1, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 75698  166079   7084      0  2           0                syz-executor.0
 75698   42857   7084      0  3   0x4000080  fsleep        syz-executor.0
 74018  463707  48612      0  2           0                syz-executor.1
 74018   38864  48612      0  3   0x4000080  fsleep        syz-executor.1
 74018   84271  48612      0  2   0x4000000                syz-executor.1
 18544  189310      0      0  3     0x14200  bored         sosplice
 81466   66650      0      0  3     0x14200  acct          acct
  7084    9238  69229      0  2       0x482                syz-executor.0
 48612  236595  69229      0  2       0x482                syz-executor.1
 69229  142017  37973      0  3        0x82  kqread        syz-fuzzer
 69229   40665  37973      0  3   0x4000082  thrsleep      syz-fuzzer
 69229  230021  37973      0  3   0x4000082  thrsleep      syz-fuzzer
 69229  410713  37973      0  3   0x4000082  thrsleep      syz-fuzzer
 69229  469430  37973      0  3   0x4000082  thrsleep      syz-fuzzer
 69229   52062  37973      0  3   0x4000082  thrsleep      syz-fuzzer
 69229  348145  37973      0  3   0x4000082  thrsleep      syz-fuzzer
 37973  139529  37063      0  3    0x10008a  pause         ksh
 37063  243477  63344      0  3        0x92  select        sshd
 62811  289529      1      0  3    0x100083  ttyin         getty
 63344  434814      1      0  3        0x80  select        sshd
  1710  355926  31173     73  3    0x100090  kqread        syslogd
 31173  374109      1      0  3    0x100082  netio         syslogd
 77201   44435      1     77  3    0x100090  poll          dhclient
 31123  462147      1      0  3        0x80  poll          dhclient
 14295  257297      0      0  2     0x14200                zerothread
 86031  229857      0      0  3     0x14200  aiodoned      aiodoned
 53182  369468      0      0  3     0x14200  syncer        update
 52208  263734      0      0  3     0x14200  cleaner       cleaner
 92913  465412      0      0  3     0x14200  reaper        reaper
 42145  129666      0      0  3     0x14200  pgdaemon      pagedaemon
 91877  519341      0      0  3     0x14200  bored         crynlk
 28170  125857      0      0  3     0x14200  bored         crypto
 52214  131049      0      0  3  0x40014200  acpi0         acpi0
 40284  125302      0      0  3     0x14200  bored         softnet
*72445  197063      0      0  7     0x14200                systqmp
 93192  116727      0      0  3     0x14200  bored         systq
 23728  184757      0      0  3  0x40014200  bored         softclock
  9274   15531      0      0  3  0x40014200                idle0
 40893  386305      0      0  3     0x14200  bored         smr
     1  204246      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
         devbuf  9523   6357K    7000K  78643K     11929        0
            pcb    14      8K       9K  78643K       112        0
         rtable   104      3K       3K  78643K       392        0
         ifaddr    87     16K      17K  78643K       156        0
       counters    19     16K      16K  78643K        19        0
       ioctlops     0      0K       2K  78643K        44        0
            iov     0      0K      24K  78643K       190        0
          mount     1      1K       1K  78643K         1        0
         vnodes  1224     77K      77K  78643K      1648        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       5K  78643K        12        0
         VM map     2      0K       0K  78643K         2        0
            sem    12      0K       1K  78643K        97        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1794    195K     288K  78643K     12646        0
      file desc     6     17K      25K  78643K       464        0
          sigio     0      0K       0K  78643K         5        0
           proc    49     38K      63K  78643K       416        0
        subproc    32      2K       2K  78643K        34        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
    ip_moptions     0      0K       0K  78643K        81        0
       in_multi    63      3K       3K  78643K        96        0
    ether_multi     1      0K       0K  78643K         3        0
            mrt     0      0K       0K  78643K         4        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys    78    344K     344K  78643K        78        0
           exec     0      0K       1K  78643K       241        0
        pagedep     1      8K       8K  78643K         1        0
       inodedep     1     32K      32K  78643K         1        0
         newblk     1      0K       0K  78643K         1        0
        VM swap     7     26K      26K  78643K         7        0
       UVM amap   133    119K     120K  78643K      1993        0
       UVM aobj    27      2K       2K  78643K        42        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K        91        0
            NDP    15      0K       0K  78643K        34        0
           temp   144   3019K    3106K  78643K     30383        0
         kqueue     0      0K       0K  78643K        14        0
      SYN cache     2     16K      16K  78643K         2        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64        9    0        2     1     0     1     1     0     8    0
rtpcb       80       67    0       65     1     0     1     1     0     8    0
rtentry    112       72    0       30     2     0     2     2     0     8    0
unpcb      120      302    0      294     1     0     1     1     0     8    0
syncache   264       10    0       10     3     2     1     1     0     8    1
tcpqe       32      176    0      176     1     1     0     1     0     8    0
tcpcb      544      214    0      209     2     1     1     2     0     8    0
ipq         40        2    0        2     2     2     0     1     0     8    0
ipqe        40       90    0       90     2     2     0     1     0     8    0
inpcb      280      612    0      603     6     4     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        2    0        2     1     1     0     1     0     8    0
nd6         48        8    0        6     1     0     1     1     0     8    0
pkpcb       40        2    0        2     1     1     0     1     0     8    0
ppxss      1128       6    0        6     1     0     1     1     0     8    1
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      322    0      130    15     1    14    15     0     8    0
art_table   32      323    0      130     2     0     2     2     0     8    0
art_node    16       71    0       32     1     0     1     1     0     8    0
sysvmsgpl   40       24    0       10     1     0     1     1     0     8    0
semupl     112        1    0        1     1     1     0     1     0     8    0
semapl     112       95    0       85     1     0     1     1     0     8    0
shmpl      112       40    0       15     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     2295    0      893    46     0    46    46     0     8    0
ffsino     240     2295    0      893    83     0    83    83     0     8    0
nchpl      144     3444    0     1829    60     0    60    60     0     8    0
uvmvnodes   72     2657    0        0    49     0    49    49     0     8    0
vnodes     208     2657    0        0   140     0   140   140     0     8    0
namei      1024   10477    0    10477     1     0     1     1     0     8    1
vcpupl     1984      13    0        0     2     0     2     2     0     8    0
vmpool     528       17    0        4     1     0     1     1     0     8    0
scxspl     192    10037    0    10037     8     7     1     7     0     8    1
plimitpl   152       57    0       50     1     0     1     1     0     8    0
sigapl     432      635    0      621     2     0     2     2     0     8    0
futexpl     56    15307    0    15305     1     0     1     1     0     8    0
knotepl    112      138    0      117     2     0     2     2     0     8    1
kqueuepl   104      132    0      128     1     0     1     1     0     8    0
pipepl     128      356    0      335     2     1     1     2     0     8    0
fdescpl    424      636    0      621     2     0     2     2     0     8    0
filepl     120     6028    0     5923     8     2     6     6     0     8    2
lockfpl    104      199    0      198     1     0     1     1     0     8    0
lockfspl    48       62    0       61     1     0     1     1     0     8    0
sessionpl  112       17    0        7     1     0     1     1     0     8    0
pgrppl      48       21    0       11     1     0     1     1     0     8    0
ucredpl     96      496    0      489     1     0     1     1     0     8    0
zombiepl   144      621    0      621     1     0     1     1     0     8    1
processpl  864      652    0      621     4     0     4     4     0     8    0
procpl     632     1242    0     1202     4     0     4     4     0     8    0
sosppl     128        6    0        6     2     1     1     1     0     8    1
sockpl     384      985    0      966     8     4     4     7     0     8    2
mcl64k     65536     49    0       49     1     0     1     1     0     8    1
mcl16k     16384      6    0        6     3     2     1     1     0     8    1
mcl12k     12288     13    0       13     2     1     1     1     0     8    1
mcl9k      9216      12    0       12     3     2     1     1     0     8    1
mcl8k      8192      24    0       24     1     0     1     1     0     8    1
mcl4k      4096      63    0       63     2     1     1     1     0     8    1
mcl2k2     2112       5    0        5     1     1     0     1     0     8    0
mcl2k      2048   69832    0    69782    15     8     7    14     0     8    0
mtagpl      80       31    0        3     2     1     1     1     0     8    0
mbufpl     256   114468    0   114288    45    25    20    38     0     8    5
bufpl      280     7605    0     2685   352     0   352   352     0     8    0
anonpl      16    92160    0    71141   105     5   100   100     0    62   15
amapchunkpl 152    3398    0     3239    20    13     7    20     0   158    0
amappl16   192     4127    0     2963    77    11    66    70     0     8    7
amappl15   184      487    0      479     1     0     1     1     0     8    0
amappl14   176      239    0      235     1     0     1     1     0     8    0
amappl13   168        1    0        0     1     0     1     1     0     8    0
amappl12   160        5    0        4     2     1     1     1     0     8    0
amappl11   152       48    0       35     1     0     1     1     0     8    0
amappl10   144        9    0        7     1     0     1     1     0     8    0
amappl9    136      557    0      554     1     0     1     1     0     8    0
amappl8    128      131    0      100     1     0     1     1     0     8    0
amappl7    120       91    0       81     1     0     1     1     0     8    0
amappl6    112       56    0       49     1     0     1     1     0     8    0
amappl5    104      152    0      142     1     0     1     1     0     8    0
amappl4     96      864    0      831     1     0     1     1     0     8    0
amappl3     88      348    0      338     1     0     1     1     0     8    0
amappl2     80     4562    0     4481     3     1     2     3     0     8    0
amappl1     72    20772    0    20330    26    17     9    20     0     8    0
amappl      80     1494    0     1440     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       18    0       17     1     0     1     1     0     8    0
aobjpl      64       41    0       15     1     0     1     1     0     8    0
uaddrrnd    24      653    0      625     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      653    0      625     1     0     1     1     0     8    0
vmmpekpl   168     7809    0     7782     2     0     2     2     0     8    0
vmmpepl    168    84711    0    82298   133    23   110   128     0   357    5
vmsppl     272      652    0      625     2     0     2     2     0     8    0
pdppl      4096    1312    0     1263     7     0     7     7     0     8    0
pvpl        32   251026    0   226931   225     4   221   223     0   265   26
pmappl     200      652    0      625     2     0     2     2     0     8    0
extentpl    40       46    0       29     1     0     1     1     0     8    0
phpool     112      183    0       39     5     0     5     5     0     8    0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/12/09 03:48 openbsd 6577a79c0f80 1508f453 .config console log report ci-openbsd-main
* Struck through repros no longer work on HEAD.