syzbot


panic: pool_do_get: pkpcb: page empty (2)

Status: upstream: reported on 2026/03/11 15:17
Reported-by: syzbot+15c98612001d3d2dc023@syzkaller.appspotmail.com
First crash: 19h11m, last: 19h11m
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd panic: pool_do_get: pkpcb: page empty 2 1 690d 690d 0/3 auto-obsoleted due to no activity on 2024/07/20 09:27

Sample crash report:
panic: pool_do_get: pkpcb: page empty
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*260412  90723      0           0  0x4000000    0  syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b9531) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a5da88,9,ffff80003c959138) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a5da88,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff800001618478,0,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff8000368de7f8,ffff80003c9593a0,ffff80003c9592f0) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c9593a0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c9593a0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x5c6d6cd0a20, count: 6
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
*cpu0: pool_do_get: pkpcb: page empty
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b9531) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a5da88,9,ffff80003c959138) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a5da88,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff800001618478,0,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff8000368de7f8,ffff80003c9593a0,ffff80003c9592f0) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c9593a0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c9593a0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x5c6d6cd0a20, count: -9
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80003c958fb0
rbx                                0
rdx               0xffff8000015d8700
rcx                                0
rax               0xffff8000368de7f8
r8                 0x101010101010101
r9                0x8080808080808080
r10               0xb095d7b4a5706125
r11               0x400aa6412d742761
r12                                0
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff816d00e5    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80003c958fa0
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor) tid=260412 pid=90723 tcnt=2 stat=onproc
    flags process=0 proc=4000000<THREAD>
    runpri=32, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff8000368de560,0xffff80002a79c558
    process=0xffff80002a7bcd90 user=0xffff80003c954000, vmspace=0xfffffd800b26f5d8
    estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 97592  386905  73251      0  2           0                syz-executor
 97592  121863  73251      0  3   0x4000080  fsleep        syz-executor
 97708  326901  25745      0  2           0                syz-executor
 97708  149822  25745      0  3   0x4000080  fsleep        syz-executor
 90723  133305  49452      0  2           0                syz-executor
*90723  260412  49452      0  7   0x4000000                syz-executor
 33167  269587  29765      0  2           0                syz-executor
 41572   33716  33688      0  2           0                syz-executor
 41572  429351  33688      0  3   0x4000080  fsleep        syz-executor
  4844  497605  54457      0  2           0                syz-executor
  4844  456702  54457      0  2   0x4000000                syz-executor
  4844  335217  54457      0  3   0x4000000  smrbar        syz-executor
 22960  330220   6739      0  3      0x3000  suspend       syz-executor
 22960   81713   6739      0  2   0x4081000                syz-executor
 73251  135641  40613      0  3        0x82  nanoslp       syz-executor
 33688  118848  40613      0  3        0x82  nanoslp       syz-executor
 25745   11846  40613      0  3        0x82  nanoslp       syz-executor
 83038  464882      1      0  3    0x100083  ttyin         getty
  6739  517412  40613      0  3        0x82  wait          syz-executor
 47624  314422  40613      0  3        0x82  wait          syz-executor
 63945  210035      0      0  3     0x14280  nfsidl        nfsio
 21243  347997      0      0  3     0x14280  nfsidl        nfsio
 71779  317641      0      0  3     0x14280  nfsidl        nfsio
 16947  128317      0      0  3     0x14280  nfsidl        nfsio
 11278  402845      0      0  3     0x14280  nfsidl        nfsio
 68761  198397      0      0  3     0x14280  nfsidl        nfsio
 75669  499097      0      0  3     0x14280  nfsidl        nfsio
 37703  336173      0      0  3     0x14280  nfsidl        nfsio
 66737  444256      0      0  3     0x14280  nfsidl        nfsio
 76342  363752      0      0  3     0x14280  nfsidl        nfsio
 27192  302452      0      0  3     0x14280  nfsidl        nfsio
 81994   42185      0      0  3     0x14280  nfsidl        nfsio
 27569  233620      0      0  3     0x14280  nfsidl        nfsio
 42689  205245      0      0  3     0x14280  nfsidl        nfsio
 67108  309409      0      0  3     0x14280  nfsidl        nfsio
 51698  329118      0      0  3     0x14280  nfsidl        nfsio
 41952  411575      0      0  3     0x14280  nfsidl        nfsio
 48907  191305      0      0  3     0x14280  nfsidl        nfsio
 98557   85929      0      0  3     0x14280  nfsidl        nfsio
 56757  135302      0      0  3     0x14280  nfsidl        nfsio
 54457  520197  40613      0  3        0x82  nanoslp       syz-executor
 49452  154856  40613      0  3        0x82  nanoslp       syz-executor
 29765  517562  40613      0  3        0x82  nanoslp       syz-executor
 40613  156282  20811      0  3        0x82  kqread        syz-executor
 20811  455942   8837      0  3    0x10008a  sigsusp       ksh
  8837  430626  68290      0  3        0x98  kqread        sshd-session
 68290  158201  87526      0  3        0x92  kqread        sshd-session
 87526  195581      1      0  3        0x88  kqread        sshd
 46685  379052   6030     73  3   0x1100090  kqread        syslogd
  6030  366449      1      0  3    0x100082  sbwait        syslogd
 76106   82441      1      0  3    0x100080  kqread        resolvd
 92375  136883  86102     77  3    0x100092  kqread        dhcpleased
 18904  426655  86102     77  3    0x100092  kqread        dhcpleased
 86102  246801      1      0  3        0x80  kqread        dhcpleased
 86156  151673      0      0  3     0x14200  bored         smr
 82349  120072      0      0  2     0x14200                zerothread
 23096   48957      0      0  3     0x14200  aiodoned      aiodoned
 80937  253754      0      0  3     0x14200  syncer        update
 59372  361908      0      0  3     0x14200  cleaner       cleaner
 32051   98688      0      0  3     0x14200  reaper        reaper
  6664  252636      0      0  3     0x14200  pgdaemon      pagedaemon
 76410   72473      0      0  3     0x14200  bored         viomb
  4243   20281      0      0  3  0x40014200  acpi0         acpi0
 78154   31481      0      0  2     0x14200                softnet0
 19357   45696      0      0  3     0x14200  bored         systqmp
 43217   16766      0      0  3     0x14200  bored         systq
 53910  368685      0      0  3  0x40014200  tmoslp        softclock
 39287  361058      0      0  3  0x40014200                idle0
     1   38123      0      0  3        0x82  wait          init
     0       0     -1      0  3  0x10010200  scheduler     swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11071  12142K   13250K 166960K     15466        0
            pcb    17     15K      23K 166960K       585        0
         rtable   248     11K      11K 166960K       978        0
             pf    36     13K      15K 166960K       235        0
         ifaddr    42      7K       8K 166960K       171        0
        ifgroup    55      2K       2K 166960K       266        0
         sysctl     4      1K       9K 166960K        23        0
       counters    37     18K      18K 166960K       180        0
       ioctlops     0      0K       4K 166960K       802        0
            iov     0      0K      28K 166960K        89        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1452     91K      91K 166960K      3253        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K        25        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K       171        0
        dirhash    12      2K       3K 166960K        39        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    17     61K      93K 166960K      1809        0
          sigio     0      0K       0K 166960K        42        0
           proc    60     59K     100K 166960K       911        0
        subproc    72      4K       4K 166960K       135        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       417        0
       in_multi    90      6K       7K 166960K       274        0
    ether_multi     1      0K       0K 166960K        22        0
            mrt     3      0K       0K 166960K        44        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   115    519K     519K 166960K       115        0
           exec     0      0K       1K 166960K       688        0
   fusefs mount     1     32K      32K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   224    151K     174K 166960K     17657        0
       UVM aobj    22     20K      20K 166960K        25        0
     pinsyscall    38     76K      94K 166960K      3064        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K       142        0
            NDP    14      0K       2K 166960K       117        0
           temp    84   9076K    9318K 166960K     74320        0
         kqueue    15     24K      32K 166960K       336        0
      SYN cache     2     16K      16K 166960K         2        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
rtpcb      120      181    0      178     1     0     1     1     0     8    0
rtentry    136      251    0      158     4     0     4     4     0     8    0
unpcb      144     1456    0     1440     5     3     2     4     0     8    1
syncache   336        4    0        4     2     2     0     1     0     8    0
tcpqe       32        6    0        6     1     1     0     1     0     8    0
tcpcb      736      725    0      719    14     7     7     7     0     8    6
arp         96       40    0       23     1     0     1     1     0     8    0
ipq         40        8    0        5     1     0     1     1     0     8    0
ipqe        40       15    0       12     1     0     1     1     0     8    0
inpcb      328     1942    0     1932    16     9     7     7     0     8    6
ip6q        72        5    0        0     1     0     1     1     0     8    0
ip6af       40        5    0        0     1     0     1     1     0     8    0
nd6        112       51    0       30     1     0     1     1     0     8    0
pkpcb       40        5    0        5     3     2     1     1     0     8    1
pkpcb: pool(0xffffffff83a5da88:pkpcb): page inconsistency: page 0x0; at page head addr 0xfffffd8066fa0f90 (p 0xfffffd8066fa0000)
kcovpl      48       15    0        7     1     0     1     1     0     8    0
mppekey    1024       2    0        2     2     1     1     1     0     8    1
ppxss      1072     120    0      117     3     2     1     1     0     8    0
pppxif     1384      13    0       13     3     2     1     1     0     8    1
pfrktable  1344      67    0       67     3     2     1     1     0     8    1
rttmr      136        4    0        4     1     1     0     1     0     8    0
art_heap8  4096       4    0        0     4     0     4     4     0     8    0
art_heap4  256     1092    0      685    39    11    28    29     0     8    1
art_table   40     1096    0      685     5     0     5     5     0     8    0
art_node    32      247    0      163     1     0     1     1     0     8    0
sysvmsgpl   40        7    0        6     1     0     1     1     0     8    0
semupl     112        5    0        5     4     3     1     1     0     8    1
semapl     112      164    0      154     1     0     1     1     0     8    0
shmpl      112       11    0        1     1     0     1     1     0     8    0
dirhash    1024      35    0       18     3     0     3     3     0     8    0
dino2pl    256     4670    0     3198    93     0    93    93     0     8    0
ffsino     256     4670    0     3198    93     0    93    93     0     8    0
nchpl      144     7194    0     5479    64     0    64    64     0     8    0
rtmask      32       19    0       18     5     4     1     1     0     8    0
vnodes     216     5926    0        0   330     0   330   330     0     8    0
namei      1024   26198    0    26198     5     3     2     2     0     8    2
vcpupl     3904      11    0        2     2     0     2     2     0     8    0
vmpool     808       11    0        2     1     0     1     1     0     8    0
kstatmem   264      172    0      144     2     0     2     2     0     8    0
acpiwqpl    32        2    0        2     1     0     1     1     1     8    1
scsiplug    72       11    0       11     4     3     1     1     0     8    1
scxspl     216    36659    0    36659    11     9     2     8     1     8    2
plimitpl   152      436    0      420     1     0     1     1     0     8    0
sigapl     424     2107    0     2044     8     0     8     8     0     8    0
knotepl    120    74994    0    74493   101    85    16    31     0     8    0
kqueuepl   184      658    0      646     7     6     1     4     0     8    0
pipepl     304      320    0      293     8     5     3     8     0     8    0
fdescpl    448     2069    0     2040     5     1     4     5     0     8    0
filepl     120    14658    0    14444    22    11    11    14     0     8    2
lockfpl    104      886    0      880     2     1     1     2     0     8    0
lockfspl    48      307    0      301     1     0     1     1     0     8    0
sessionpl  144       31    0       23     1     0     1     1     0     8    0
pgrppl      48       62    0       46     1     0     1     1     0     8    0
ucredpl    104     2049    0     2037     1     0     1     1     0     8    0
zombiepl   144     2218    0     2216     2     1     1     1     0     8    0
processpl  1152    2107    0     2044     5     0     5     5     0     8    0
procpl     664     4516    0     4446     7     0     7     7     0     8    0
sosppl     176       10    0       10     3     2     1     1     0     8    1
sockpl     552     3695    0     3665    18     8    10    10     0     8    7
mcl64k     65536     52    0       52     5     4     1     1     0     8    1
mcl16k     16384      4    0        4     2     1     1     1     0     8    1
mcl12k     12288      3    0        3     2     1     1     1     0     8    1
mcl9k      9216       2    0        2     1     0     1     1     0     8    1
mcl8k      8192      19    0       19     5     4     1     1     0     8    1
mcl4k      4096    4603    0     4548    16     7     9    15     0     8    1
mcl2k      2048    1786    0     1775     8     6     2     5     0     8    0
mtagpl      96      167    0       39     4     0     4     4     0     8    0
mbufpl     256    23416    0    23127    96    67    29    84     0     8    8
bufpl      280    12487    0     6269   445     0   445   445     0     8    0
anonpl      24   332986    0   329663   130    58    72    72     0   187   31
amapchunkpl 152   62453    0    61972    69    34    35    35     0   158   16
amappl16   200     7158    0     7124    86    70    16    29     0     8    8
amappl15   192        4    0        3     1     0     1     1     0     8    0
amappl14   184      484    0      483     1     0     1     1     0     8    0
amappl13   176      124    0      114     1     0     1     1     0     8    0
amappl12   168     2330    0     2301     2     0     2     2     0     8    0
amappl11   160       30    0       30     1     1     0     1     0     8    0
amappl10   152       97    0       87     1     0     1     1     0     8    0
amappl9    144      266    0      266     1     1     0     1     0     8    0
amappl8    136      124    0      121     1     0     1     1     0     8    0
amappl7    128       48    0       45     1     0     1     1     0     8    0
amappl6    120      360    0      349     1     0     1     1     0     8    0
amappl5    112       76    0       69     1     0     1     1     0     8    0
amappl4    104      485    0      453     1     0     1     1     0     8    0
amappl3     96    10425    0    10335     3     0     3     3     0     8    0
amappl2     88     2125    0     2060     2     0     2     2     0     8    0
amappl1     80    16080    0    15533    13     1    12    13     0     8    0
amappl      88    16569    0    16408     5     0     5     5     0    92    0
uvmvnodes   80      160    0        0     4     0     4     4     0     8    0
dma32768   32768      1    0        1     1     1     0     1     0     8    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       2    0        1     1     0     1     1     0     8    0
dma256     256        8    0        8     2     2     0     1     0     8    0
dma128     128      254    0      254     1     1     0     1     0     8    0
dma64       64        7    0        7     2     1     1     1     0     8    1
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       19    0       18     1     0     1     1     0     8    0
aobjpl      72       24    0        3     1     0     1     1     0     8    0
uaddrrnd    24     2069    0     2039     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     2069    0     2039     1     0     1     1     0     8    0
vmmpekpl   168    16389    0    16351     3     0     3     3     0     8    0
vmmpepl    168   133940    0   132096   138    35   103   103     0   357   17
vmsppl     368     2068    0     2039     4     1     3     4     0     8    0
rwobjpl     40    35834    0    34805    16     0    16    16     0     8    1
pdppl      4096    4166    0     4091   117    42    75    80     0     8    0
pvpl        32   938986    0   930436   272   117   155   155     0   265   50
pmappl     216     2079    0     2041     4     1     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      519    0      161    12     0    12    12     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b9531) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a5da88,9,ffff80003c959138) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a5da88,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff800001618478,0,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff8000368de7f8,ffff80003c9593a0,ffff80003c9592f0) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c9593a0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c9593a0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x5c6d6cd0a20, count: -9
ddb> machine ddbcpu 1
No such command
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b9531) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a5da88,9,ffff80003c959138) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a5da88,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff800001618478,0,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c959260,3,0) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff8000368de7f8,ffff80003c9593a0,ffff80003c9592f0) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c9593a0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c9593a0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x5c6d6cd0a20, count: -9

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/11 15:17 openbsd 177cf78f1bc3 b4075e21 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main panic: pool_do_get: pkpcb: page empty
* Struck through repros no longer work on HEAD.