assert "!_kernel_lock_held()" failed in kern

[openbsd] assert "!_kernel_lock_held()" failed in kern_fork.c
Status: upstream: reported on 2019/02/04 20:02
Reported-by: syzbot+790495af3d9b4f5e45cd@syzkaller.appspotmail.com
First crash: 14d, last: 11h02m
duplicates:
Title	Repro	Count	Last	Reported	Patched	Status
panic: malloc: allocationp atnoico: lakerrgnee,l tdyiapgen o=s ti2c, saisszeer t=i on "!_kernel_lock_held()" failed:		1	10d	10d	0/3	closed as dup on 2019/02/09 12:22
Sample crash report:
panic: malloc: allocation too lapanic: kernel diagnostic assertion "!_kernel_lock_held()" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_fork.c", line 689
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*456124  93832      0           0          0    1  syz-executor0
 325706  98771      0           0  0x4000000    0  syz-executor1
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399
panic() at panic+0x16c sys/kern/subr_prf.c:208
__assert(ffffffff81d851a4,ffff800020c9afe0,0,1) at __assert+0x24 sys/kern/subr_prf.c:155
proc_trampoline_mp() at proc_trampoline_mp+0x13e
end trace frame: 0x0, count: 11
https://www.openbsd.org/ddb.html describes the minimum info required in bug
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ddb{1}> 
ddb{1}> set $lines = 0
ddb{1}> show panic
malloc: allocation too large, type = 2, size = 2795614184

ddb{1}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399
panic() at panic+0x16c sys/kern/subr_prf.c:208
__assert(ffffffff81d851a4,ffff800020c9afe0,0,1) at __assert+0x24 sys/kern/subr_prf.c:155
proc_trampoline_mp() at proc_trampoline_mp+0x13e
end trace frame: 0x0, count: -4
ddb{1}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff800020c9af40
rbx               0xffff800020c9afe0
rdx               0xffffffff81f35469    cy_pio_rec+0x2087
rcx                                0
rax                                0
r8                0xffffffff81d85b34    kprintf+0x174
r9                               0x1
r10               0x24998f93492e841f
r11               0x9aa35d0ccd32cff1
r12                     0x3000000008
r13               0xffff800020c9af50
r14                            0x104
r15                              0x1
rip               0xffffffff81bb44e8    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff800020c9af30
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor0) pid=456124 stat=onproc
    flags process=0 proc=0
    pri=77, usrpri=77, nice=20
    forw=0xffffffffffffffff, list=0xffff800020b93c38,0xffffffff822f3540
    process=0xffff800020b946a0 user=0xffff800020c96000, vmspace=0xfffffd807f00d5a0
    estcpu=36, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
*93832  456124  45843      0  7           0                syz-executor0
 98771  203516  66159      0  2           0                syz-executor1
 98771  523674  66159      0  2   0x4000000                syz-executor1
 98771  325706  66159      0  7   0x4000000                syz-executor1
 46171  211371      1      0  3    0x100083  ttyin         getty
 66159   38399  10143      0  3        0x82  nanosleep     syz-executor1
  8310    6098      0      0  3     0x14200  bored         sosplice
 45843  403842  10143      0  2         0x2                syz-executor0
 10143  444340  16510      0  3        0x82  thrsleep      syz-fuzzer
 10143   79237  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143  146831  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143  207272  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143  373813  16510      0  2   0x4000082                syz-fuzzer
 10143  317235  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143   51627  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143   44355  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143  206779  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143  158187  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143   41613  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 10143  167307  16510      0  3   0x4000082  thrsleep      syz-fuzzer
 16510  346339  73508      0  3    0x10008a  pause         ksh
 73508  341183  66822      0  3        0x92  select        sshd
 66822  508748      1      0  3        0x80  select        sshd
 13681   89846  82737     73  3    0x100090  kqread        syslogd
 82737  135640      1      0  3    0x100082  netio         syslogd
 61662  186186      1     77  3    0x100090  poll          dhclient
 19689  301258      1      0  3        0x80  poll          dhclient
 74185  290560      0      0  2     0x14200                zerothread
 55813  253497      0      0  3     0x14200  aiodoned      aiodoned
 62673   70834      0      0  3     0x14200  syncer        update
 54296  183453      0      0  3     0x14200  cleaner       cleaner
 47796    4873      0      0  3     0x14200  reaper        reaper
 21049   43707      0      0  3     0x14200  pgdaemon      pagedaemon
 42349   75413      0      0  3     0x14200  bored         crynlk
 98110  381286      0      0  3     0x14200  bored         crypto
 55899  297276      0      0  3  0x40014200  acpi0         acpi0
 58240  186505      0      0  3  0x40014200                idle1
 44493  121655      0      0  3     0x14200  bored         softnet
 72936  346411      0      0  3     0x14200  bored         systqmp
  5537  284790      0      0  3     0x14200  bored         systq
 16049  123987      0      0  3  0x40014200  bored         softclock
 22349  203629      0      0  3  0x40014200                idle0
     1  255570      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
Process 98771 (syz-executor1) thread 0xffff800020b93c38 (325706)
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff822d6828) locked @ /syzkaller/managers/multicore/kernel/sys/sys/syscall_mi.h:90
Process 45843 (syz-executor0) thread 0xffff800020b759d0 (403842)
exclusive rrwlock inode r = 0 (0xfffffd8066708a28) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_ihash.c:140
exclusive rrwlock inode r = 0 (0xfffffd8077ca6e70) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547
ddb{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim Kern Lim
         devbuf  9517  10470K   10470K  78643K     10930        0        0
            pcb    23      9K      10K  78643K       423        0        0
         rtable   100      3K       4K  78643K       432        0        0
         ifaddr    52     12K      13K  78643K       163        0        0
       counters    39     33K      33K  78643K        39        0        0
       ioctlops     0      0K       2K  78643K        22        0        0
            iov     0      0K      16K  78643K        82        0        0
          mount     1      1K       1K  78643K         1        0        0
         vnodes  1203     75K      76K  78643K      1852        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        22        0        0
         VM map     2      1K       1K  78643K         2        0        0
            sem    12      0K       1K  78643K       113        0        0
        dirhash    12      2K       2K  78643K        12        0        0
           ACPI  1792    194K     288K  78643K     12592        0        0
      file desc     6     17K      25K  78643K       956        0        0
          sigio     1      0K       0K  78643K        20        0        0
           proc    42     38K      58K  78643K       486        0        0
        subproc    64  65538K   67586K  78643K       175        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       118        0        0
       in_multi    33      2K       2K  78643K        97        0        0
    ether_multi     1      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    90    397K     397K  78643K        90        0        0
           exec     0      0K       1K  78643K       227        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    90     20K      21K  78643K      3839        0        0
       UVM aobj    54      2K       2K  78643K        59        0        0
        memdesc     1      4K       4K  78643K         1        0        0
    crypto data     1      1K       1K  78643K         1        0        0
    ip6_options     0      0K       1K  78643K        13        0        0
            NDP    10      0K       0K  78643K        49        0        0
           temp   156   2367K    2434K  78643K      5558        0        0
         kqueue     0      0K       0K  78643K        17        0        0
      SYN cache     2     16K      16K  78643K         2        0        0
ddb{1}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64        7    0        3     1     0     1     1     0     8    0
inpcbpl    280      417    0      410     1     0     1     1     0     8    0
plimitpl   152       28    0       21     1     0     1     1     0     8    0
plcache    128       20    0        0     1     0     1     1     0     8    0
rtentry    112       68    0       28     2     0     2     2     0     8    0
syncache   264        4    0        4     1     1     0     1     0     8    0
tcpcb      544      153    0      149     1     0     1     1     0     8    0
nd6         48       10    0        6     1     0     1     1     0     8    0
ppxss      1128      17    0       17     6     5     1     1     0     8    1
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      317    0      129    12     0    12    12     0     8    0
art_table   32      318    0      129     2     0     2     2     0     8    0
art_node    16       67    0       33     1     0     1     1     0     8    0
sysvmsgpl   40       16    0        7     2     1     1     1     0     8    0
semupl     112        2    0        2     2     2     0     1     0     8    0
semapl     112      107    0       97     1     0     1     1     0     8    0
shmpl      112       57    0        5     2     0     2     2     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     3254    0     1860    46     0    46    46     0     8    0
ffsino     272     3254    0     1860    94     0    94    94     0     8    0
nchpl      144     4742    0     3169    59     0    59    59     0     8    0
uvmvnodes   72     3436    0        0    63     0    63    63     0     8    0
vnodes     200     3436    0        0   181     0   181   181     0     8    0
namei      1024   13608    0    13608     1     0     1     1     0     8    1
percpumem   16       30    0        0     1     0     1     1     0     8    0
scsiplug    64        1    0        1     1     1     0     1     0     8    0
scxspl     192    12309    0    12309    13    10     3     6     0     8    3
sigapl     432     1116    0     1102     2     0     2     2     0     8    0
futexpl     56    10675    0    10675     1     0     1     1     0     8    1
knotepl    112      378    0      351     4     3     1     2     0     8    0
kqueuepl   104      321    0      319     1     0     1     1     0     8    0
pipepl     112      606    0      587     2     1     1     1     0     8    0
fdescpl    488     1117    0     1102     3     1     2     3     0     8    0
filepl     152     6565    0     6467     9     4     5     5     0     8    1
lockfpl    104      273    0      272     5     4     1     1     0     8    0
lockfspl    32      515    0      514     5     4     1     1     0     8    0
sessionpl  112       22    0       12     1     0     1     1     0     8    0
pgrppl      48       30    0       20     1     0     1     1     0     8    0
ucredpl     96     1698    0     1691     1     0     1     1     0     8    0
zombiepl   144     1102    0     1102     2     1     1     1     0     8    1
processpl  840     1132    0     1102     4     0     4     4     0     8    0
procpl     600     3145    0     3102     6     2     4     5     0     8    0
srpgc       64       18    0       18     1     1     0     1     0     8    0
sosppl     128       18    0       18     3     3     0     1     0     8    0
sockpl     384      811    0      794     5     2     3     3     0     8    1
mcl64k     65536    378    0        0    48    11    37    48     0     8    1
mcl16k     16384      2    0        0     1     0     1     1     0     8    0
mcl12k     12288      8    0        0     1     0     1     1     0     8    0
mcl9k      9216       7    0        0     1     0     1     1     0     8    0
mcl8k      8192       4    0        0     1     0     1     1     0     8    0
mcl4k      4096      11    0        0     2     0     2     2     0     8    0
mcl2k2     2112       3    0        0     1     0     1     1     0     8    0
mcl2k      2048     106    0        0    13     1    12    13     0     8    0
mtagpl      80        1    0        0     1     0     1     1     0     8    0
mbufpl     256      471    0        0    28     0    28    28     0     8    0
bufpl      256     6350    0      980   336     0   336   336     0     8    0
anonpl      16   123312    0   115727    89    56    33    47     0   125    2
amapchunkpl 152    6367    0     6253    18    12     6    10     0   158    0
amappl16   192     6065    0     5692    66    45    21    31     0     8    1
amappl15   184      466    0      465     2     1     1     1     0     8    0
amappl14   176      302    0      298     2     1     1     1     0     8    0
amappl13   168       28    0       25     1     0     1     1     0     8    0
amappl12   160       15    0       15     1     1     0     1     0     8    0
amappl11   152      198    0      189     1     0     1     1     0     8    0
amappl10   144       65    0       63     2     1     1     1     0     8    0
amappl9    136      344    0      343     1     0     1     1     0     8    0
amappl8    128      172    0      145     1     0     1     1     0     8    0
amappl7    120       42    0       35     1     0     1     1     0     8    0
amappl6    112      341    0      332     1     0     1     1     0     8    0
amappl5    104      593    0      582     1     0     1     1     0     8    0
amappl4     96      295    0      275     2     1     1     2     0     8    0
amappl3     88      375    0      370     1     0     1     1     0     8    0
amappl2     80     9498    0     9449     2     0     2     2     0     8    0
amappl1     72    32815    0    32386    24    14    10    19     0     8    0
amappl      72     3408    0     3367     1     0     1     1     0    75    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
dma64       64      259    0      259     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       58    0        5     1     0     1     1     0     8    0
uaddrrnd    24     1117    0     1102     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1117    0     1102     1     0     1     1     0     8    0
vmmpekpl   168    12570    0    12548     2     0     2     2     0     8    0
vmmpepl    168   125935    0   124557   109    45    64    73     0   357    2
vmsppl     360     1116    0     1102     2     0     2     2     0     8    0
pdppl      4096    2241    0     2204     6     1     5     6     0     8    0
pvpl        32   350672    0   340062   172    70   102   123     0   265   13
pmappl     224     1116    0     1102     1     0     1     1     0     8    0
extentpl    40       39    0       25     1     0     1     1     0     8    0
phpool     112      549    0       15    16     0    16    16     0     8    0
All crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-openbsd-multicore	2019/02/04 20:01	openbsd	6e31582a	d672172c	.config	log	report
ci-openbsd-multicore	2019/02/19 08:32	openbsd	644ac04b	59f36113	.config	log	report