syzbot


panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr ADDR+24 ADDR!=ADDR (2)

Status: closed as dup on 2019/10/23 13:31
Reported-by: syzbot+7f790d25478dfb11f18c@syzkaller.appspotmail.com
First crash: 1887d, last: 1859d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
pool: cpu free list modified: mbufpl syz 15863 1570d 1856d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr ADDR+24 ADDR!=ADDR 1 2175d 2175d 0/3 closed as dup on 2019/01/02 21:02

Sample crash report:
login: panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f7bde00+24 0x4f2056623dbe4c86!=0x4f2056e250dc8086
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
  16335   6941      0         0x2  0x4000000    1  syz-execprog
*233966  96312      0     0x14000 0x40000200    0K softclock
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
pool_cache_get(ffffffff8266e920) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline]
pool_cache_get(ffffffff8266e920) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892
pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572
m_get(2,1) at m_get+0x4c sys/kern/uipc_mbuf.c:250
ip6_output(fffffd806f2b3a00,ffffffff82525c08,0,0,ffff800020a25368,0) at ip6_output+0x203 sys/netinet6/ip6_output.c:198
mld6_sendpkt(ffff800000a5ff00,83,0) at mld6_sendpkt+0x2da sys/netinet6/mld6.c:465
mld6_fasttimeo() at mld6_fasttimeo+0x162 mld6_checktimer sys/netinet6/mld6.c:363 [inline]
mld6_fasttimeo() at mld6_fasttimeo+0x162 sys/netinet6/mld6.c:341
pffasttimo(ffffffff825254c8) at pffasttimo+0x85 sys/kern/uipc_domain.c:292
timeout_run(ffffffff825254c8) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline]
timeout_run(ffffffff825254c8) at timeout_run+0xc4 sys/kern/kern_timeout.c:474
softclock_thread(ffff800020a109e0) at softclock_thread+0x16a sys/kern/kern_timeout.c:553
end trace frame: 0x0, 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{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f7bde00+24 0x4f2056623dbe4c86!=0x4f2056e250dc8086
ddb{0}> 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
pool_cache_get(ffffffff8266e920) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline]
pool_cache_get(ffffffff8266e920) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892
pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572
m_get(2,1) at m_get+0x4c sys/kern/uipc_mbuf.c:250
ip6_output(fffffd806f2b3a00,ffffffff82525c08,0,0,ffff800020a25368,0) at ip6_output+0x203 sys/netinet6/ip6_output.c:198
mld6_sendpkt(ffff800000a5ff00,83,0) at mld6_sendpkt+0x2da sys/netinet6/mld6.c:465
mld6_fasttimeo() at mld6_fasttimeo+0x162 mld6_checktimer sys/netinet6/mld6.c:363 [inline]
mld6_fasttimeo() at mld6_fasttimeo+0x162 sys/netinet6/mld6.c:341
pffasttimo(ffffffff825254c8) at pffasttimo+0x85 sys/kern/uipc_domain.c:292
timeout_run(ffffffff825254c8) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline]
timeout_run(ffffffff825254c8) at timeout_run+0xc4 sys/kern/kern_timeout.c:474
softclock_thread(ffff800020a109e0) at softclock_thread+0x16a sys/kern/kern_timeout.c:553
end trace frame: 0x0, count: -11
ddb{0}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff800020a24fa0
rbx               0xffff800020a25050
rdx                             0x8b
rcx                              0x2
rax                              0x1
r8                0xffffffff81918aaf    kprintf+0x16f
r9                               0x1
r10               0x3b6d92addafe76b3
r11               0x5c8f88fb0ea67fb4
r12                     0x3000000008
r13               0xffff800020a24fb0
r14                            0x100
r15                              0x1
rip               0xffffffff814a9118    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff800020a24f90
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb{0}> show proc
PROC (softclock) pid=233966 stat=onproc
    flags process=14000<NOZOMBIE,SYSTEM> proc=40000200<SYSTEM,CPUPEG>
    pri=0, usrpri=50, nice=20
    forw=0xffffffffffffffff, list=0xffff800020a10ed0,0xffff800020a10500
    process=0xffff800020a12000 user=0xffff800020a20000, vmspace=0xffffffff8264e768
    estcpu=0, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 34585  205451   6941      0  2       0x482                syz-executor.0
  6941  154567  44399      0  3        0x82  thrsleep      syz-execprog
  6941   16335  44399      0  7   0x4000002                syz-execprog
  6941   40422  44399      0  3   0x4000082  thrsleep      syz-execprog
  6941  406182  44399      0  2   0x4000482                syz-execprog
  6941  204358  44399      0  3   0x4000082  thrsleep      syz-execprog
  6941  218268  44399      0  3   0x4000082  thrsleep      syz-execprog
  6941  211326  44399      0  3   0x4000082  thrsleep      syz-execprog
  6941  231970  44399      0  3   0x4000082  kqread        syz-execprog
  6941   50409  44399      0  3   0x4000082  thrsleep      syz-execprog
 44399  164548  33624      0  3    0x10008a  pause         ksh
 33624  172677  85636      0  3        0x92  select        sshd
 88851  334876      1      0  3    0x100083  ttyin         getty
 85636    4516      1      0  3        0x80  select        sshd
 50094    6671  67254     74  3    0x100092  bpf           pflogd
 67254  478384      1      0  3        0x80  netio         pflogd
 30728  401288   9354     73  3    0x100090  kqread        syslogd
  9354  352130      1      0  3    0x100082  netio         syslogd
 69346  340816      1     77  3    0x100090  poll          dhclient
 22319   11148      1      0  3        0x80  poll          dhclient
 92912  194794      0      0  3     0x14200  pgzero        zerothread
 19892   14843      0      0  3     0x14200  aiodoned      aiodoned
 71510   80580      0      0  3     0x14200  syncer        update
 41573  185418      0      0  3     0x14200  cleaner       cleaner
 56991  259665      0      0  3     0x14200  reaper        reaper
 77657  413955      0      0  3     0x14200  pgdaemon      pagedaemon
 42855  484986      0      0  3     0x14200  bored         crynlk
 91755  146741      0      0  3     0x14200  bored         crypto
 26605  294576      0      0  3  0x40014200  acpi0         acpi0
 64377  281100      0      0  3  0x40014200                idle1
 31253  451183      0      0  3     0x14200  bored         softnet
 18924  159260      0      0  3     0x14200  bored         systqmp
 99261  430370      0      0  3     0x14200  bored         systq
*96312  233966      0      0  7  0x40014200                softclock
 46376  243500      0      0  3  0x40014200                idle0
 11992  268674      0      0  3     0x14200  bored         smr
     1  259211      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
Process 96312 (softclock) thread 0xffff800020a109e0 (233966)
exclusive rwlock netlock r = 0 (0xffffffff824ca238)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1163
#1  mld6_fasttimeo+0x1d sys/netinet6/mld6.c:336
#2  pffasttimo+0x85 sys/kern/uipc_domain.c:292
#3  timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline]
#3  timeout_run+0xc4 sys/kern/kern_timeout.c:474
#4  softclock_thread+0x16a sys/kern/kern_timeout.c:553
#5  proc_trampoline+0x1c
shared rwlock timeout r = 0 (0xffffffff824b5210)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1163
#1  timeout_run+0xb9 sys/kern/kern_timeout.c:473
#2  softclock_thread+0x16a sys/kern/kern_timeout.c:553
#3  proc_trampoline+0x1c
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82625ee0)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1163
#1  __mp_acquire_count+0x51 sys/kern/kern_lock.c:227
#2  mi_switch+0x392 sys/kern/sched_bsd.c:436
#3  sleep_finish+0x113 sys/kern/kern_synch.c:373
#4  softclock_thread+0x103 sys/kern/kern_timeout.c:548
#5  proc_trampoline+0x1c
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim Kern Lim
         devbuf  9457   6385K    6385K  78643K     10544        0        0
            pcb    13      8K       8K  78643K        13        0        0
         rtable    77      2K       2K  78643K       165        0        0
         ifaddr    32      9K       9K  78643K       210        0        0
       counters    39     33K      33K  78643K        39        0        0
       ioctlops     0      0K       4K  78643K      1468        0        0
          mount     1      1K       1K  78643K         1        0        0
         vnodes  1181     74K      74K  78643K      1186        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      1K       1K  78643K         2        0        0
            sem     2      0K       0K  78643K         2        0        0
        dirhash    12      2K       2K  78643K        12        0        0
           ACPI  1808    196K     290K  78643K     12765        0        0
      file desc     2      4K      12K  78643K       195        0        0
           proc    59     63K      83K  78643K       384        0        0
    NFS srvsock     1      0K       0K  78643K         1        0        0
     NFS daemon     1     16K      16K  78643K         1        0        0
       in_multi    22      1K       1K  78643K        22        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    18     79K      79K  78643K        18        0        0
           exec     0      0K       1K  78643K       199        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    72     12K      12K  78643K      1134        0        0
       UVM aobj     2      2K       2K  78643K         2        0        0
        memdesc     1      4K       4K  78643K         1        0        0
    crypto data     1      1K       1K  78643K         1        0        0
            NDP     5      0K       0K  78643K         7        0        0
           temp    48   3546K    3610K  78643K      3691        0        0
      SYN cache     2     16K      16K  78643K         2        0        0
ddb{0}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64        4    0        1     1     0     1     1     0     8    0
plcache    128       20    0        0     1     0     1     1     0     8    0
rtpcb       80       17    0       15     1     0     1     1     0     8    0
rtentry    112       34    0        4     1     0     1     1     0     8    0
unpcb      120       29    0       19     1     0     1     1     0     8    0
syncache   264        5    0        5     1     1     0     1     0     8    0
tcpcb      544        8    0        5     1     0     1     1     0     8    0
inpcb      280      211    0      205     1     0     1     1     0     8    0
nd6         48        2    0        0     1     0     1     1     0     8    0
pfosfp      40      846    0      423     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfstitem    24       10    0        0     1     0     1     1     0     8    0
pfstkey    112       10    0        0     1     0     1     1     0     8    0
pfstate    328       10    0        0     1     0     1     1     0     8    0
pfrule     1360      21    0       16     2     1     1     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      168    0        2    11     0    11    11     0     8    0
art_table   32      169    0        2     2     0     2     2     0     8    0
art_node    16       33    0        6     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     1599    0      197    46     0    46    46     0     8    0
ffsino     272     1599    0      197    94     0    94    94     0     8    0
nchpl      144     2015    0      404    60     0    60    60     0     8    0
uvmvnodes   72     1609    0        0    30     0    30    30     0     8    0
vnodes     208     1609    0        0    85     0    85    85     0     8    0
namei      1024    4850    0     4850     1     0     1     1     0     8    1
percpumem   16       30    0        0     1     0     1     1     0     8    0
scxspl     192     5143    0     5143     2     1     1     2     0     8    1
plimitpl   152       15    0        8     1     0     1     1     0     8    0
sigapl     432      403    0      390     2     0     2     2     0     8    0
knotepl    112       39    0       28     1     0     1     1     0     8    0
kqueuepl   104        2    0        0     1     0     1     1     0     8    0
pipepl     112      510    0      497     1     0     1     1     0     8    0
fdescpl    488      404    0      390     3     0     3     3     0     8    0
filepl     152     1831    0     1773     3     0     3     3     0     8    0
lockfpl    104        5    0        4     1     0     1     1     0     8    0
lockfspl    48        3    0        2     1     0     1     1     0     8    0
sessionpl  112       19    0        9     1     0     1     1     0     8    0
pgrppl      48       19    0        9     1     0     1     1     0     8    0
ucredpl     96       52    0       43     1     0     1     1     0     8    0
zombiepl   144      390    0      389     1     0     1     1     0     8    0
processpl  896      419    0      389     4     0     4     4     0     8    0
procpl     632      427    0      389     4     0     4     4     0     8    0
sockpl     384      257    0      239     2     0     2     2     0     8    0
mcl4k      4096       3    0        0     1     0     1     1     0     8    0
mcl2k      2048      78    0        0    10     0    10    10     0     8    0
mtagpl      80        1    0        0     1     0     1     1     0     8    0
mbufpl     256       99    0        0     6     0     6     6     0     8    0
bufpl      256     6065    0     1315   297     0   297   297     0     8    0
anonpl      16    26702    0    24904    14     1    13    13     0   124    5
amapchunkpl 152     927    0      862     5     0     5     5     0   158    2
amappl16   192      878    0      833     3     0     3     3     0     8    0
amappl14   176       22    0       20     1     0     1     1     0     8    0
amappl13   168        1    0        1     1     0     1     1     0     8    1
amappl12   160      187    0      183     2     1     1     1     0     8    0
amappl11   152       53    0       37     1     0     1     1     0     8    0
amappl10   144       18    0       15     1     0     1     1     0     8    0
amappl9    136      463    0      457     1     0     1     1     0     8    0
amappl8    128      129    0      119     1     0     1     1     0     8    0
amappl7    120       33    0       30     1     0     1     1     0     8    0
amappl6    112       78    0       70     1     0     1     1     0     8    0
amappl5    104      298    0      285     1     0     1     1     0     8    0
amappl4     96      677    0      650     1     0     1     1     0     8    0
amappl3     88      117    0      111     1     0     1     1     0     8    0
amappl2     80     1305    0     1244     3     0     3     3     0     8    1
amappl1     72    16587    0    16174    25     7    18    20     0     8    8
amappl      80      655    0      627     1     0     1     1     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        1    0        0     1     0     1     1     0     8    0
uaddrrnd    24      404    0      390     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      404    0      390     1     0     1     1     0     8    0
vmmpekpl   168     7477    0     7454     2     0     2     2     0     8    0
vmmpepl    168    40312    0    39384    86     6    80    80     0   357   37
vmsppl     368      403    0      390     2     0     2     2     0     8    0
pdppl      4096     815    0      780     6     0     6     6     0     8    1
pvpl        32   130719    0   126541   115     0   115   115     0   265   81
pmappl     232      403    0      390     1     0     1     1     0     8    0
extentpl    40       41    0       26     1     0     1     1     0     8    0
phpool     112      437    0        3    13     0    13    13     0     8    0
ddb{0}> 

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/20 19:47 openbsd 06f3ae2aae65 8c88c9c1 .config console log report syz ci-openbsd-multicore
2019/09/28 15:56 openbsd dd0887e41377 eb6b9855 .config console log report syz ci-openbsd-multicore
2019/09/22 18:35 openbsd 2f346d2b6595 d96e88f3 .config console log report syz ci-openbsd-multicore
2019/10/16 19:18 openbsd 1ef0822a19b5 8c88c9c1 .config console log report ci-openbsd-multicore
2019/10/13 23:20 openbsd cfc53b516f65 2f661ec4 .config console log report ci-openbsd-multicore
2019/10/12 02:50 openbsd b8fc78b9a375 426631dd .config console log report ci-openbsd-multicore
2019/10/10 20:50 openbsd 1eea934d9376 a4efa8c0 .config console log report ci-openbsd-multicore
2019/10/08 16:57 openbsd 0767cd885e7f 64612bfd .config console log report ci-openbsd-multicore
2019/10/08 10:22 openbsd 0767cd885e7f 28ac6e64 .config console log report ci-openbsd-multicore
2019/10/07 16:12 openbsd 29a2b068f14b 28ac6e64 .config console log report ci-openbsd-multicore
2019/10/05 06:48 openbsd b5642e9fefea f3f7d9c8 .config console log report ci-openbsd-multicore
2019/10/03 14:27 openbsd 0a65a5060995 fc17ba49 .config console log report ci-openbsd-multicore
2019/10/03 08:07 openbsd c722278fddec 2e29b534 .config console log report ci-openbsd-multicore
2019/10/03 07:31 openbsd c722278fddec 2e29b534 .config console log report ci-openbsd-multicore
2019/10/02 23:06 openbsd c722278fddec 2e29b534 .config console log report ci-openbsd-multicore
2019/10/02 10:05 openbsd 65ab43f212c4 2e29b534 .config console log report ci-openbsd-multicore
2019/09/30 05:07 openbsd f6e3733c141c c1ad5441 .config console log report ci-openbsd-multicore
2019/09/28 14:06 openbsd dd0887e41377 eb6b9855 .config console log report ci-openbsd-multicore
2019/09/22 17:56 openbsd 2f346d2b6595 d96e88f3 .config console log report ci-openbsd-multicore
* Struck through repros no longer work on HEAD.