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: 38d, last: 34d
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 727d 727d 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
*213606  22713      0           0  0x4000000    0  syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b8dff) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a3e160,9,ffff80003c9211a8) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a3e160,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff80000166af68,2,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff80003c913258,ffff80003c921410,ffff80003c921360) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c921410) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c921410) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xcbffd14b730, 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(ffffffff833b8dff) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a3e160,9,ffff80003c9211a8) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a3e160,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff80000166af68,2,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff80003c913258,ffff80003c921410,ffff80003c921360) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c921410) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c921410) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xcbffd14b730, count: -9
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80003c921020
rbx                                0
rdx                                0
rcx                                0
rax               0xffff80003c913258
r8                 0x101010101010101
r9                0x8080808080808080
r10               0xcc3be0682925ac39
r11               0x420feccdf62135d9
r12                                0
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff82289575    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80003c921010
ss                                 0
db_enter+0x25:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor) tid=213606 pid=22713 tcnt=2 stat=onproc
    flags process=0 proc=4000000<THREAD>
    runpri=83, usrpri=83, slppri=17, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80003c915260,0xffffffff8399f700
    process=0xffff8000ffff4020 user=0xffff80003c91c000, vmspace=0xfffffd8074047748
    estcpu=33, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 22713   62288  98264      0  2           0                syz-executor
*22713  213606  98264      0  7   0x4000000                syz-executor
 42166  303558  10013      0  2           0                syz-executor
 42166   32061  10013      0  3   0x4000080  fsleep        syz-executor
 29887  181963  94417      0  2           0                syz-executor
 29887  309395  94417      0  3   0x4000080  fsleep        syz-executor
 29887  257052  94417      0  3   0x4000080  fsleep        syz-executor
 84877  471833  54785      0  3        0x80  nanoslp       syz-executor
 84877  355855  54785      0  3   0x4000080  bell          syz-executor
 84877  501398  54785      0  3   0x4000080  pipewr        syz-executor
 84877  129358  54785      0  3   0x4000080  fsleep        syz-executor
 84334  512893  92418      0  3        0x80  nanoslp       syz-executor
 84334  293282  92418      0  3   0x4000080  netacc        syz-executor
 84334  438310  92418      0  3   0x4000080  fsleep        syz-executor
 84334  326451  92418      0  3   0x4000080  fsleep        syz-executor
 36634  459096  24498      0  3        0x80  nanoslp       syz-executor
 36634  484778  24498      0  3   0x4000080  wsevent_read  syz-executor
 36634   44568  24498      0  3   0x4000080  fsleep        syz-executor
 36634   53990  24498      0  3   0x4000080  fsleep        syz-executor
 19245  359889  49805      0  3        0x80  nanoslp       syz-executor
 19245  359325  49805      0  3   0x4000080  ttyout        syz-executor
 19245  305787  49805      0  3   0x4000080  fsleep        syz-executor
 55134  322767  36713      0  3      0x3000  suspend       syz-executor
 55134  385264  36713      0  2   0x4081000                syz-executor
 55134   87407  36713      0  3   0x4081000  inode         syz-executor
 55134  118275  36713      0  3   0x4081000  inode         syz-executor
 56337  166371      1      0  3    0x100083  ttyin         getty
 94417  270848  36313      0  3        0x82  nanoslp       syz-executor
 16675   83972      0      0  3     0x14280  nfsidl        nfsio
 58293  252162      0      0  3     0x14280  nfsidl        nfsio
 26005   51109      0      0  3     0x14280  nfsidl        nfsio
 16087  412397      0      0  3     0x14280  nfsidl        nfsio
 14223  216107      0      0  3     0x14280  nfsidl        nfsio
 77629  151459      0      0  3     0x14280  nfsidl        nfsio
  6254  412015      0      0  3     0x14280  nfsidl        nfsio
 38098  355993      0      0  3     0x14280  nfsidl        nfsio
 90811  181412      0      0  3     0x14280  nfsidl        nfsio
 85544   20863      0      0  3     0x14280  nfsidl        nfsio
 67909  118769      0      0  3     0x14280  nfsidl        nfsio
 71301  463226      0      0  3     0x14280  nfsidl        nfsio
 11521  309643      0      0  3     0x14280  nfsidl        nfsio
 92711  218093      0      0  3     0x14280  nfsidl        nfsio
 27910  506138      0      0  3     0x14280  nfsidl        nfsio
 82155  172433      0      0  3     0x14280  nfsidl        nfsio
 78682  197865      0      0  3     0x14280  nfsidl        nfsio
 78265  492193      0      0  3     0x14280  nfsidl        nfsio
 59622  411835      0      0  3     0x14280  nfsidl        nfsio
 86488  427160      0      0  3     0x14280  nfsidl        nfsio
 49805  237526  36313      0  3        0x82  nanoslp       syz-executor
 54785   13613  36313      0  3        0x82  nanoslp       syz-executor
 92418  157282  36313      0  3        0x82  nanoslp       syz-executor
 98264  128278  36313      0  3        0x82  nanoslp       syz-executor
 36713  387716  36313      0  3        0x82  wait          syz-executor
 24498   84485  36313      0  3        0x82  nanoslp       syz-executor
 10013  299264  36313      0  3        0x82  nanoslp       syz-executor
 36313    3979    461      0  3        0x82  kqread        syz-executor
   461  420249  54924      0  3    0x10008a  sigsusp       ksh
 54924  118408  69871      0  3        0x98  kqread        sshd-session
 69871  193280  23264      0  3        0x92  kqread        sshd-session
 23264  132713      1      0  3        0x88  kqread        sshd
 78200  461337  57735     73  3   0x1100090  kqread        syslogd
 57735  399458      1      0  3    0x100082  sbwait        syslogd
   790  405843      1      0  3    0x100080  kqread        resolvd
 45514  359095  71109     77  3    0x100092  kqread        dhcpleased
 17258  178453  71109     77  3    0x100092  kqread        dhcpleased
 71109  441266      1      0  3        0x80  kqread        dhcpleased
 72132   96703      0      0  3     0x14200  bored         smr
  5770  518367      0      0  2     0x14200                zerothread
  8857  172685      0      0  3     0x14200  aiodoned      aiodoned
 10440  439938      0      0  3     0x14200  syncer        update
 78982  241810      0      0  3     0x14200  cleaner       cleaner
 38639  262240      0      0  3     0x14200  reaper        reaper
 97516    8350      0      0  3     0x14200  pgdaemon      pagedaemon
 30103   26148      0      0  3     0x14200  bored         viomb
 27974  436039      0      0  3  0x40014200  acpi0         acpi0
 68597  379854      0      0  3     0x14200  bored         softnet0
 78515  268968      0      0  3     0x14200  bored         systqmp
 79901  423142      0      0  3     0x14200  bored         systq
  9442  466867      0      0  3  0x40014200  tmoslp        softclock
 54610  291633      0      0  3  0x40014200                idle0
     1  412654      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 11054  12312K   12627K 166960K     13247        0
            pcb    18     14K      16K 166960K       230        0
         rtable   219      8K       9K 166960K       523        0
             pf    31     13K      15K 166960K        93        0
         ifaddr    37      6K       7K 166960K        80        0
        ifgroup    43      1K       2K 166960K       118        0
         sysctl     3      1K       9K 166960K        11        0
       counters    32     17K      18K 166960K        67        0
       ioctlops     0      0K       4K 166960K       154        0
            iov     0      0K      28K 166960K        44        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1374     86K      87K 166960K      2177        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     3      5K       9K 166960K        13        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K       103        0
        dirhash    12      2K       2K 166960K        18        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    18     65K     240K 166960K       863        0
          sigio     0      0K       0K 166960K        11        0
           proc    60     59K      91K 166960K       597        0
        subproc    72      4K       4K 166960K        81        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        76        0
       in_multi    77      5K       7K 166960K       138        0
    ether_multi     1      0K       0K 166960K        10        0
            mrt     2      0K       0K 166960K        23        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    91    413K     413K 166960K        91        0
           exec     0      0K       1K 166960K       442        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   248    169K     169K 166960K      9489        0
       UVM aobj    97     14K      14K 166960K       103        0
     pinsyscall    39     78K      93K 166960K      1974        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        55        0
            NDP    10      0K       2K 166960K        53        0
           temp    79   9076K    9148K 166960K     36783        0
         kqueue    14     22K      30K 166960K       139        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       91    0       88     1     0     1     1     0     8    0
rtentry    136      149    0       63     4     0     4     4     0     8    0
unpcb      144      524    0      508     4     1     3     3     0     8    2
syncache   336        5    0        5     1     1     0     1     0     8    0
tcpcb      736      302    0      295    10     3     7     7     0     8    6
arp         96       26    0        8     1     0     1     1     0     8    0
ipq         40        3    0        2     2     1     1     1     0     8    0
ipqe        40        6    0        5     2     1     1     1     0     8    0
inpcb      328      739    0      722    12     5     7     7     0     8    5
ip6q        72        2    0        0     1     0     1     1     0     8    0
ip6af       40        2    0        0     1     0     1     1     0     8    0
nd6        112       30    0       10     1     0     1     1     0     8    0
pkpcb       40       66    0       66     2     1     1     1     0     8    1
pkpcb: pool(0xffffffff83a3e160:pkpcb): page inconsistency: page 0x0; at page head addr 0xfffffd806cbd7f90 (p 0xfffffd806cbd7000)
kcovpl      48        9    0        1     1     0     1     1     0     8    0
mppekey    1024       1    0        1     1     1     0     1     0     8    0
ppxss      1072      26    0       26     2     1     1     1     0     8    1
pppxif     1384       4    0        4     2     1     1     1     0     8    1
pfstscr     40        2    0        2     2     1     1     1     0     8    1
pfrktable  1344       3    0        3     2     1     1     1     0     8    1
pfstitem    24        5    0        0     1     0     1     1     0     8    0
pfstkey    128        9    0        5     1     0     1     1     0     8    0
pfstate    384        5    0        2     1     0     1     1     0     8    0
pfrule     1360       5    0        5     2     1     1     1     0     8    1
art_heap8  4096       3    0        0     3     0     3     3     0     8    0
art_heap4  256      577    0      213    29     4    25    29     0     8    2
art_table   40      580    0      213     5     0     5     5     0     8    0
art_node    32      147    0       70     1     0     1     1     0     8    0
sysvmsgpl   40        2    0        1     2     1     1     1     0     8    0
semupl     112        1    0        1     1     0     1     1     0     8    1
semapl     112      101    0       91     1     0     1     1     0     8    0
shmpl      112       93    0        4     3     0     3     3     0     8    0
dirhash    1024      21    0        4     3     0     3     3     0     8    0
dino2pl    256     2991    0     1544    92     0    92    92     0     8    0
ffsino     256     2991    0     1544    92     0    92    92     0     8    0
nchpl      144     4169    0     2472    64     0    64    64     0     8    0
rtmask      32        4    0        4     2     1     1     1     0     8    1
vnodes     216     3551    0        0   198     0   198   198     0     8    0
namei      1024   13816    0    13816     3     2     1     2     0     8    1
vcpupl     3904       7    0        2     1     0     1     1     0     8    0
vmpool     808        7    0        2     1     0     1     1     0     8    0
kstatmem   264       68    0       48     2     0     2     2     0     8    0
acpiwqpl    32        1    0        1     1     0     1     1     1     8    1
scsiplug    72        4    0        4     2     1     1     1     0     8    1
scxspl     216    20339    0    20339     8     7     1     8     1     8    1
plimitpl   152      181    0      161     1     0     1     1     0     8    0
sigapl     424     1157    0     1094     9     1     8     8     0     8    0
knotepl    120    39816    0    39766    11     1    10    10     0     8    8
kqueuepl   184      262    0      251     3     2     1     3     0     8    0
pipepl     304      184    0      156     3     0     3     3     0     8    0
fdescpl    448     1124    0     1094     5     1     4     5     0     8    0
filepl     120     6530    0     6301    11     2     9    11     0     8    1
lockfpl    104      311    0      309     1     0     1     1     0     8    0
lockfspl    48      120    0      118     1     0     1     1     0     8    0
sessionpl  144       25    0       17     1     0     1     1     0     8    0
pgrppl      48       44    0       28     1     0     1     1     0     8    0
ucredpl    104     1366    0     1354     1     0     1     1     0     8    0
zombiepl   144     1370    0     1369     1     0     1     1     0     8    0
processpl  1152    1157    0     1094     5     0     5     5     0     8    0
procpl     664     2354    0     2273     8     0     8     8     0     8    1
sosppl     176        4    0        4     2     1     1     1     0     8    1
sockpl     552     1436    0     1399    12     4     8     8     0     8    4
mcl64k     65536     62    0       61     1     0     1     1     0     8    0
mcl12k     12288      1    0        1     1     1     0     1     0     8    0
mcl8k      8192      12    0       12     2     1     1     1     0     8    1
mcl4k      4096    3444    0     3390    15     7     8    15     0     8    1
mcl2k      2048     808    0      797     3     0     3     3     0     8    1
mtagpl      96       87    0        9     2     0     2     2     0     8    0
mbufpl     256    13706    0    13451    18     0    18    18     0     8    0
bufpl      280     8677    0     2459   445     0   445   445     0     8    0
anonpl      24   181653    0   176243    58     4    54    58     0   187   15
amapchunkpl 152   30801    0    30071    39     4    35    35     0   158    6
amappl16   200     3789    0     3631    22     7    15    21     0     8    6
amappl15   192        9    0        9     1     1     0     1     0     8    0
amappl14   184      424    0      423     1     0     1     1     0     8    0
amappl13   176      137    0      127     1     0     1     1     0     8    0
amappl12   168     1373    0     1343     2     0     2     2     0     8    0
amappl11   160        5    0        5     1     1     0     1     0     8    0
amappl10   152       59    0       49     1     0     1     1     0     8    0
amappl9    144      260    0      259     1     0     1     1     0     8    0
amappl8    136      105    0      103     1     0     1     1     0     8    0
amappl7    128       82    0       80     1     0     1     1     0     8    0
amappl6    120      259    0      249     1     0     1     1     0     8    0
amappl5    112      177    0      170     1     0     1     1     0     8    0
amappl4    104      477    0      443     2     0     2     2     0     8    0
amappl3     96     5357    0     5258     3     0     3     3     0     8    0
amappl2     88     1222    0     1157     2     0     2     2     0     8    0
amappl1     80    12506    0    11968    13     0    13    13     0     8    0
amappl      88     8663    0     8479     5     0     5     5     0    92    0
uvmvnodes   80      118    0        0     3     0     3     3     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        6    0        6     1     1     0     1     0     8    0
dma128     128      253    0      253     1     1     0     1     0     8    0
dma64       64        7    0        7     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      72      102    0        6     2     0     2     2     0     8    0
uaddrrnd    24     1124    0     1094     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1124    0     1094     1     0     1     1     0     8    0
vmmpekpl   168    10606    0    10571     2     0     2     2     0     8    0
vmmpepl    168    78482    0    76486    97     4    93    97     0   357    6
vmsppl     368     1123    0     1094     4     1     3     4     0     8    0
rwobjpl     40    23351    0    22139    14     0    14    14     0     8    0
pdppl      4096    2268    0     2197   104    33    71    78     0     8    0
pvpl        32   504139    0   492693   143    11   132   143     0   265   26
pmappl     216     1130    0     1096     2     0     2     2     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      392    0       57    10     0    10    10     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(ffffffff833b8dff) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a3e160,9,ffff80003c9211a8) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a3e160,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff80000166af68,2,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff80003c913258,ffff80003c921410,ffff80003c921360) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c921410) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c921410) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xcbffd14b730, 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(ffffffff833b8dff) at panic+0x1cf sys/kern/subr_prf.c:198
pool_do_get(ffffffff83a3e160,9,ffff80003c9211a8) at pool_do_get+0x537 sys/kern/subr_pool.c:732
pool_get(ffffffff83a3e160,9) at pool_get+0x11a sys/kern/subr_pool.c:-1
pfkeyv2_attach(ffff80000166af68,2,1) at pfkeyv2_attach+0xe9 sys/net/pfkeyv2.c:-1
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f pru_attach sys/sys/protosw.h:275 [inline]
socreate(1e,ffff80003c9212d0,3,2) at socreate+0x22f sys/kern/uipc_socket.c:220
sys_socket(ffff80003c913258,ffff80003c921410,ffff80003c921360) at sys_socket+0x124 sys/kern/uipc_syscalls.c:102
syscall(ffff80003c921410) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c921410) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xcbffd14b730, count: -9

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/15 03:59 openbsd fd49698d88e5 351cb5cf .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main panic: pool_do_get: pkpcb: page empty
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.