syzbot


assert "pr->ps_threadcnt == NUM" failed in kern_exit.c (2)

Status: upstream: reported on 2025/11/01 01:28
Reported-by: syzbot+89d36c350dc9849653e3@syzkaller.appspotmail.com
First crash: 71d, last: 3d22h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd assert "pr->ps_threadcnt == NUM" failed in kern_exit.c -1 1 465d 465d 0/3 auto-obsoleted due to no activity on 2024/12/31 12:53

Sample crash report:
panic: kernel diagnostic assertion "pr->ps_threadcnt == 0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_exit.c", line 886
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*106312  31761      0     0x14000      0x200    0  reaper
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8337dcc8) at panic+0x1cf sys/kern/subr_prf.c:198
__assert(ffffffff833bc878,ffffffff833e2974,376,ffffffff833e29a9) at __assert+0x29 sys/kern/subr_prf.c:-1
process_zap(ffff8000318f6d18) at process_zap+0x31d sys/kern/kern_exit.c:887
reaper(ffff80002a72cf90) at reaper+0x290 sys/kern/kern_exit.c:521
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
*cpu0: kernel diagnostic assertion "pr->ps_threadcnt == 0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_exit.c", line 886
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8337dcc8) at panic+0x1cf sys/kern/subr_prf.c:198
__assert(ffffffff833bc878,ffffffff833e2974,376,ffffffff833e29a9) at __assert+0x29 sys/kern/subr_prf.c:-1
process_zap(ffff8000318f6d18) at process_zap+0x31d sys/kern/kern_exit.c:887
reaper(ffff80002a72cf90) at reaper+0x290 sys/kern/kern_exit.c:521
end trace frame: 0x0, count: -5
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80002a763a00
rbx                          0x40000    acpi_pdirpa+0x2be71
rdx                                0
rcx                                0
rax               0xffff80002a72cf90
r8                 0x101010101010101
r9                0x8080808080808080
r10               0xdbd68aef0e0fae70
r11               0xdb2da703359bbed2
r12                                0
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff82ffb8c5    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80002a7639f0
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb> show proc
PROC (reaper) tid=106312 pid=31761 tcnt=1 stat=onproc
    flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>
    runpri=32, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a72c000,0xffff80002a72d768
    process=0xffff8000ffffe880 user=0xffff80002a75e000, vmspace=0xffffffff83995af0
    estcpu=0, cpticks=5, pctcpu=0.0, user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
  4514  487226  54943      0  2           0                syz-executor
  4514  355994  54943      0  3   0x4000080  fsleep        syz-executor
 27909  352119  39127  60929  2        0x10                syz-executor
 27909  428696  39127  60929  3   0x4000090  fsleep        syz-executor
 37128  164855  29914      0  2           0                syz-executor
 37128  343630  29914      0  3   0x4000080  fsleep        syz-executor
 37128  112257  29914      0  3   0x4000080  fsleep        syz-executor
 37128  342212  29914      0  3   0x4000080  fsleep        syz-executor
 22478  492625      0      0  3     0x14280  nfsidl        nfsio
 69031  369111  91335      0  2           0                syz-executor
 69031  338067  91335      0  3   0x4000080  fsleep        syz-executor
 18048  417852      0      0  3     0x14280  nfsidl        nfsio
 99588  309325  66051  60929  3        0x90  nanoslp       syz-executor
 99588  455869  66051  60929  3   0x4000090  fifow         syz-executor
 99588  277705  66051  60929  2   0x4000010                syz-executor
 37639  344886  73379  60928  2        0x10                syz-executor
 37639   59558  73379  60928  3   0x4000090  ttyout        syz-executor
 37639  251437  73379  60928  3   0x4000090  fsleep        syz-executor
 55361  356044  92167      0  2           0                syz-executor
 55361   33096  92167      0  2   0x4000000                syz-executor
 55361  283053  92167      0  3   0x4000080  sysctllk      syz-executor
 66051  170982  34142      0  3        0x82  nanoslp       syz-executor
 63128  495562      0      0  3     0x14200  acct          acct
 29914   66150  34142      0  2         0x2                syz-executor
 23619    5470  34142      0  2       0xc82                syz-executor
 92167  310144  34142      0  3        0x82  nanoslp       syz-executor
 73379  132845  34142      0  3        0x82  nanoslp       syz-executor
 39127   52422  34142      0  3         0x2  kqpsl         syz-executor
 91335  258324  34142      0  2       0xc82                syz-executor
 54943  157626  34142      0  3         0x2  kqpsl         syz-executor
 34142   78098  86777      0  3        0x82  kqread        syz-executor
 86777  154784   7190      0  3    0x10008a  sigsusp       ksh
  7190  332897  40478      0  3        0x98  kqread        sshd-session
 40478  239979  50585      0  3        0x92  kqread        sshd-session
  5223  403668      1      0  3    0x100083  ttyin         getty
 50585  136392      1      0  3        0x88  kqread        sshd
 90709  121631  92090     73  3   0x1100090  kqread        syslogd
 92090   30344      1      0  3    0x100082  sbwait        syslogd
 53433  182112      1      0  3    0x100080  kqread        resolvd
 11046  283745  32624     77  3    0x100092  kqread        dhcpleased
 81698   28018  32624     77  3    0x100092  kqread        dhcpleased
 32624   43755      1      0  3        0x80  kqread        dhcpleased
 46078  179654      0      0  3     0x14200  bored         smr
 18926  379392      0      0  2     0x14200                zerothread
 96076  455753      0      0  3     0x14200  aiodoned      aiodoned
 46931  419145      0      0  3     0x14200  syncer        update
 14862  359289      0      0  3     0x14200  cleaner       cleaner
*31761  106312      0      0  7     0x14200                reaper
 56537   66092      0      0  3     0x14200  pgdaemon      pagedaemon
 72281   27875      0      0  3     0x14200  bored         viomb
 17456  160930      0      0  3  0x40014200  acpi0         acpi0
 92585  426220      0      0  3     0x14200  bored         softnet0
 27638  441058      0      0  3     0x14200  bored         systqmp
 90525  487360      0      0  3     0x14200  bored         systq
 18163  401579      0      0  3  0x40014200  tmoslp        softclock
 32636  283739      0      0  3  0x40014200                idle0
     1  380305      0      0  3     0x80082  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 11040  12104K   12549K 166960K     13030        0
            pcb    17     16K      18K 166960K       236        0
         rtable   215      7K       8K 166960K       586        0
             pf    32     13K      14K 166960K        83        0
         ifaddr    40      7K       8K 166960K        76        0
        ifgroup    53      2K       2K 166960K       114        0
         sysctl     3      1K       9K 166960K         7        0
       counters    33     17K      18K 166960K        69        0
       ioctlops     0      0K       4K 166960K       255        0
            iov     0      0K      16K 166960K        30        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1337     84K      85K 166960K      2002        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       5K 166960K         6        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K        27        0
        dirhash    12      2K       2K 166960K        21        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    17     61K     240K 166960K       730        0
          sigio     0      0K       0K 166960K         9        0
           proc    60     59K     100K 166960K       533        0
        subproc    72      4K       4K 166960K        85        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        52        0
       in_multi    92      7K       7K 166960K       130        0
    ether_multi     1      0K       0K 166960K         5        0
            mrt     1      0K       0K 166960K         6        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       450        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   231    172K     173K 166960K      8599        0
       UVM aobj    13      4K       4K 166960K        13        0
     pinsyscall    38     76K      91K 166960K      1831        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        16        0
            NDP    11      0K       1K 166960K        48        0
           temp    53   8666K    8794K 166960K     29027        0
         kqueue    16     22K      30K 166960K       134        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       83    0       79     1     0     1     1     0     8    0
rtentry    136      139    0       47     4     0     4     4     0     8    0
unpcb      144      449    0      430     4     0     4     4     0     8    3
syncache   336        6    0        6     2     1     1     1     0     8    1
tcpqe       32        2    0        2     1     0     1     1     0     8    1
tcpcb      736      318    0      312     7     0     7     7     0     8    6
arp         96       21    0        3     1     0     1     1     0     8    0
ipq         40        2    0        0     1     0     1     1     0     8    0
ipqe        40        2    0        0     1     0     1     1     0     8    0
inpcb      328     1081    0     1071    16     7     9    12     0     8    7
ip6q        72        6    0        4     1     0     1     1     0     8    0
ip6af       40       10    0        8     1     0     1     1     0     8    0
nd6        112       31    0        7     1     0     1     1     0     8    0
pkpcb       40        2    0        2     1     0     1     1     0     8    1
kcovpl      48        9    0        1     1     0     1     1     0     8    0
mppekey    1024       1    0        1     1     0     1     1     0     8    1
ppxss      1072      27    0       27     1     0     1     1     0     8    1
pppxif     1384       6    0        6     1     0     1     1     0     8    1
pfrktable  1344      65    0       65     1     0     1     1     0     8    1
pfrule     1344       1    0        0     1     0     1     1     0     8    0
rttmr      136        2    0        2     1     0     1     1     0     8    1
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      624    0      247    29     1    28    28     0     8    4
art_table   40      625    0      247     5     0     5     5     0     8    0
art_node    32      138    0       55     1     0     1     1     0     8    0
sysvmsgpl   40        8    0        5     1     0     1     1     0     8    0
semapl     112       24    0       14     1     0     1     1     0     8    0
shmpl      112       10    0        0     1     0     1     1     0     8    0
dirhash    1024      23    0        6     3     0     3     3     0     8    0
dino2pl    256     2798    0     1303    95     0    95    95     0     8    0
ffsino     256     2798    0     1303    95     0    95    95     0     8    0
nchpl      144     3799    0     2102    64     0    64    64     0     8    0
rtmask      32        6    0        6     1     0     1     1     0     8    1
vnodes     216     3150    0        0   175     0   175   175     0     8    0
namei      1024   12677    0    12677     5     2     3     3     0     8    3
kstatmem   264       60    0       38     2     0     2     2     0     8    0
scsiplug    72        2    0        2     1     0     1     1     0     8    1
scxspl     216    11261    0    11261    10     2     8     8     1     8    8
plimitpl   152      114    0       97     1     0     1     1     0     8    0
sigapl     424     1009    0      963     6     0     6     6     0     8    0
knotepl    120    29737    0    29686    17     7    10    15     0     8    8
kqueuepl   184      201    0      191     1     0     1     1     0     8    0
pipepl     304      167    0      139     3     0     3     3     0     8    0
fdescpl    448      992    0      963     5     1     4     5     0     8    0
filepl     120     6400    0     6182    16     2    14    14     0     8    6
lockfpl    104      276    0      274     1     0     1     1     0     8    0
lockfspl    48       89    0       87     1     0     1     1     0     8    0
sessionpl  144       25    0       17     1     0     1     1     0     8    0
pgrppl      48       46    0       30     1     0     1     1     0     8    0
ucredpl    104     1238    0     1224     1     0     1     1     0     8    0
zombiepl   144     1343    0     1342     1     0     1     1     0     8    0
processpl  1152    1009    0      963     4     0     4     4     0     8    0
procpl     664     2016    0     1958     6     0     6     6     0     8    1
sosppl     176        8    0        8     1     0     1     1     0     8    1
sockpl     552     1626    0     1593    24    13    11    13     0     8    7
mcl64k     65536     39    0       38     2     1     1     1     0     8    0
mcl16k     16384      9    0        9     1     0     1     1     0     8    1
mcl9k      9216       1    0        1     1     0     1     1     0     8    1
mcl8k      8192      39    0       39     2     1     1     1     0     8    1
mcl4k      4096    3265    0     3214    15     7     8    15     0     8    1
mcl2k2     2112       1    0        1     1     0     1     1     0     8    1
mcl2k      2048    1164    0     1155     3     1     2     2     0     8    0
mtagpl      96       27    0        9     2     1     1     1     0     8    0
mbufpl     256    10931    0    10718    17     0    17    17     0     8    2
bufpl      280     3576    0      120   247     0   247   247     0     8    0
anonpl      24   164057    0   160376    47     2    45    45     0   187   22
amapchunkpl 152   28099    0    27242    41     6    35    35     0   158    0
amappl16   200     2577    0     2519    18     6    12    15     0     8    8
amappl15   192        5    0        5     1     1     0     1     0     8    0
amappl14   184        7    0        7     2     1     1     1     0     8    1
amappl13   176      416    0      415     1     0     1     1     0     8    0
amappl12   168     1345    0     1307     2     0     2     2     0     8    0
amappl11   160       46    0       46     1     1     0     1     0     8    0
amappl10   152       42    0       32     1     0     1     1     0     8    0
amappl9    144      249    0      249     1     1     0     1     0     8    0
amappl8    136       21    0       19     1     0     1     1     0     8    0
amappl7    128       84    0       83     1     0     1     1     0     8    0
amappl6    120      275    0      264     1     0     1     1     0     8    0
amappl5    112       92    0       85     1     0     1     1     0     8    0
amappl4    104      400    0      376     1     0     1     1     0     8    0
amappl3     96     4710    0     4625     3     0     3     3     0     8    0
amappl2     88     1137    0     1064     2     0     2     2     0     8    0
amappl1     80    12093    0    11555    16     1    15    15     0     8    2
amappl      88     7768    0     7605     5     0     5     5     0    92    0
uvmvnodes   80      117    0        0     3     0     3     3     0     8    0
dma4096    4096       2    0        2     2     1     1     1     0     8    1
dma1024    1024       1    0        0     1     0     1     1     0     8    0
dma256     256        7    0        7     2     1     1     1     0     8    1
dma128     128      253    0      253     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       18    0       17     1     0     1     1     0     8    0
aobjpl      72       12    0        0     1     0     1     1     0     8    0
uaddrrnd    24      992    0      963     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      992    0      963     1     0     1     1     0     8    0
vmmpekpl   168     9605    0     9574     2     0     2     2     0     8    0
vmmpepl    168    69722    0    67915    93     3    90    90     0   357    8
vmsppl     368      991    0      962     4     1     3     4     0     8    0
rwobjpl     40    21136    0    20143    14     1    13    13     0     8    1
pdppl      4096    1990    0     1924    96    30    66    78     0     8    0
pvpl        32   435112    0   424838   117     3   114   114     0   265   25
pmappl     216      991    0      962     2     0     2     2     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      388    0       48    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(ffffffff8337dcc8) at panic+0x1cf sys/kern/subr_prf.c:198
__assert(ffffffff833bc878,ffffffff833e2974,376,ffffffff833e29a9) at __assert+0x29 sys/kern/subr_prf.c:-1
process_zap(ffff8000318f6d18) at process_zap+0x31d sys/kern/kern_exit.c:887
reaper(ffff80002a72cf90) at reaper+0x290 sys/kern/kern_exit.c:521
end trace frame: 0x0, count: -5
ddb> machine ddbcpu 1
No such command
ddb> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8337dcc8) at panic+0x1cf sys/kern/subr_prf.c:198
__assert(ffffffff833bc878,ffffffff833e2974,376,ffffffff833e29a9) at __assert+0x29 sys/kern/subr_prf.c:-1
process_zap(ffff8000318f6d18) at process_zap+0x31d sys/kern/kern_exit.c:887
reaper(ffff80002a72cf90) at reaper+0x290 sys/kern/kern_exit.c:521
end trace frame: 0x0, count: -5

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/07 10:02 openbsd c7117ed52e15 15f6fd08 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2026/01/04 15:59 openbsd 079c76c73fb6 e3fbc05e .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/31 15:24 openbsd f516ab5f0d05 49aa01cc .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/24 14:48 openbsd 1dc30a6de584 5dc09de1 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/16 21:12 openbsd 11531c4859ff a066d2bc .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/15 14:37 openbsd 2c50c5af38ad a066d2bc .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/10 10:57 openbsd f5c5b16722b5 48b27acc .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/09 18:13 openbsd 9bea02201100 fc20f974 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/09 05:28 openbsd bf8f637750de fc20f974 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/12/05 11:57 openbsd 9dbbe670f20c cee4cb10 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/26 20:34 openbsd 856b2687a9ff c116feb4 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/24 16:56 openbsd 879ea5f6fdb7 bf6fe8fe .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/14 06:41 openbsd 83ff66b05700 07e030de .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/12 23:22 openbsd 4bd49954ab16 07e030de .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/09 04:05 openbsd e187005a6767 4e1406b4 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/08 19:03 openbsd f09b465a1938 4e1406b4 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/06 12:37 openbsd 05dcfb71c047 a6c9c731 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
2025/11/01 01:28 openbsd c58a321e760c 2c50b6a9 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "pr->ps_threadcnt == NUM" failed in kern_exit.c
* Struck through repros no longer work on HEAD.