KASAN: invalid memory access in knote_processfork

Status: upstream: reported on 2026/08/14 10:23
Reported-by: syzbot+114d7893c5502e911555@syzkaller.appspotmail.com
First crash: 4d21h, last: 4d15h

Sample crash report:
panic: Caught invalid memory access at ffff800001b59652 size 2 op 0
Stopped at      db_enter+0x17:  popq    %rbp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*312607  52940      0           0  0x4000000    1K syz-executor
  24112  72704      0           0          0    0  syz-executor
db_enter() at db_enter+0x17 sys/arch/amd64/amd64/db_interface.c:457
panic(ffffffff846414f3) at panic+0x270 sys/kern/subr_prf.c:198
__asan_load2_noabort(ffff800001b59652) at __asan_load2_noabort+0x107
knote_processfork(ffffffff85423320,5eca) at knote_processfork+0x603 sys/kern/kern_event.c:2289
fork1(ffffffff85422fc0,f0,ffffffff82b481d0,0,0,ffff800036af8720) at fork1+0x1225 sys/kern/kern_fork.c:511
kthread_create(ffffffff82b481d0,0,ffffffff85d6daa0,ffffffff84b32660) at kthread_create+0xa8 sys/kern/kern_kthread.c:61
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e acct_start sys/kern/kern_acct.c:300 [inline]
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e sys/kern/kern_acct.c:151
syscall(ffff800036af8af0) at syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036af8af0) at syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x88d2c7e4090, count: 6
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}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: Caught invalid memory access at ffff800001b59652 size 2 op 0
ddb{1}> show kasan
KASAN: invalid read of 2 bytes at 0xffff800001b59652 from pc 0xffffffff82996e13
KASAN: first bad byte at 0xffff800001b59652 (+0); shadow 0xfd: pool use-after-free (or unallocated item)
KASAN: 0xffff800001b59652 is 50 bytes inside the 120-byte item [0xffff800001b59620..0xffff800001b59698) in pool 'knotepl'
KASAN: allocated at:
#0  pool_get+0x770 sys/kern/subr_pool.c:834
#1  kqueue_register+0x2f2 sys/kern/kern_event.c:1431
#2  sys_kevent+0x409 sys/kern/kern_event.c:1301
#3  syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#3  syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
#4  Xsyscall+0x128
KASAN: freed at:
#0  pool_put+0x79 sys/kern/subr_pool.c:1019
#1  kqueue_scan+0x1191 sys/kern/kern_event.c:1797
#2  sys_kevent+0x997 sys/kern/kern_event.c:1336
#3  syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#3  syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
#4  Xsyscall+0x128
KASAN: pc: knote_processfork+0x603
KASAN: call trace:
#0  __asan_load2_noabort+0xe6 kasan_shadow_check sys/kern/subr_kasan.c:-1 [inline]
#0  __asan_load2_noabort+0xe6 sys/kern/subr_kasan.c:1097
#1  knote_processfork+0x603 sys/kern/kern_event.c:2289
#2  fork1+0x1225 sys/kern/kern_fork.c:511
#3  kthread_create+0xa8 sys/kern/kern_kthread.c:61
#4  sys_acct+0x35e acct_start sys/kern/kern_acct.c:300 [inline]
#4  sys_acct+0x35e sys/kern/kern_acct.c:151
#5  syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#5  syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
#6  Xsyscall+0x128
KASAN: shadow of 0xffff800001b59500..0xffff800001b59780 (1 cell = 8 bytes):
 0xffff800001b59500: 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08
 0xffff800001b59580: 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08
>0xffff800001b59600: 08 08 08 08 fd fd fd fd fd fd[fd]fd fd fd fd fd
 0xffff800001b59680: fd fd fd 08 08 08 08 08 08 08 08 08 08 08 08 08
 0xffff800001b59700: 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08
KASAN: legend: 00 valid; 01..07 partial; fb malloc redzone; fc malloc freed; fd pool freed; fe kmem; fa global; f1..f4/f8 stack/scope
ddb{1}> trace
db_enter() at db_enter+0x17 sys/arch/amd64/amd64/db_interface.c:457
panic(ffffffff846414f3) at panic+0x270 sys/kern/subr_prf.c:198
__asan_load2_noabort(ffff800001b59652) at __asan_load2_noabort+0x107
knote_processfork(ffffffff85423320,5eca) at knote_processfork+0x603 sys/kern/kern_event.c:2289
fork1(ffffffff85422fc0,f0,ffffffff82b481d0,0,0,ffff800036af8720) at fork1+0x1225 sys/kern/kern_fork.c:511
kthread_create(ffffffff82b481d0,0,ffffffff85d6daa0,ffffffff84b32660) at kthread_create+0xa8 sys/kern/kern_kthread.c:61
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e acct_start sys/kern/kern_acct.c:300 [inline]
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e sys/kern/kern_acct.c:151
syscall(ffff800036af8af0) at syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036af8af0) at syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x88d2c7e4090, count: -9
ddb{1}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff800036af82d0
rbx               0xffff800036af8340
rdx                                0
rcx               0xffff800028fe3ff0
rax               0xffff800000170100
r8                 0x101010101010101
r9                0x8080808080808080
r10               0xffff800036af80b8
r11               0xffffffff81fc8940    x86_bus_space_io_read_1
r12               0xffffffff846414f3    .str.219+0x9bc53
r13               0xffff800028fe4c08
r14               0xffff800028fe4e07
r15                              0x1
rip               0xffffffff83ac6a17    db_enter+0x17
cs                               0x8
rflags                         0x246
rsp               0xffff800036af82d0
ss                              0x10
db_enter+0x17:  popq    %rbp
ddb{1}> show proc
PROC (syz-executor) tid=312607 pid=52940 tcnt=3 stat=onproc
    flags process=0 proc=4000000<THREAD>
    runpri=32, usrpri=74, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff800037b0b4e8,0xffff800037b0a800
    process=0xffff800045ffb038 user=0xffff800036aed000, vmspace=0xffff800001c503e8
    estcpu=24, cpticks=25, pctcpu=0.3, user=0, sys=25, intr=0
ddb{1}> ps
   PID     TID   PPID   UID  S      PRLAGS     PFLAGS WAIT      COMMAND
 24266  518676      0     0  2     0x14000      0x200           swapper
  3507   85361  76976     0  2           0          0           syz-executor
  3507   15847  76976     0  3           0  0x4000080 fsleep    syz-executor
 92941  417040  92625     0  2      0x1000    0x80000           syz-executor
 92941  136697  92625     0  3      0x1000  0x4002000 suspend   syz-executor
 67335  427700  58046     0  2           0          0           syz-executor
 67335  470748  58046     0  3           0  0x4000080 fsleep    syz-executor
 67335   58111  58046     0  3           0  0x4000080 fsleep    syz-executor
 67335  511080  58046     0  2           0  0x4000000           syz-executor
 55907  263144  29959     0  2           0          0           syz-executor
 55907  133089  29959     0  3           0  0x4000080 kqread    syz-executor
 55907  251696  29959     0  3           0  0x4000080 fsleep    syz-executor
 52940  112046  50056     0  2           0          0           syz-executor
 52940  211639  50056     0  3           0  0x4000080 kqread    syz-executor
*52940  312607  50056     0  7           0  0x4000000           syz-executor
 72704   24112  95468     0  7           0          0           syz-executor
 72704  463004  95468     0  3           0  0x4000080 kqread    syz-executor
 72704  256958  95468     0  3           0  0x4000080 fsleep    syz-executor
 76976    6346  61916     0  3         0x2       0x80 nanoslp   syz-executor
 58046  235216  61916     0  3         0x2       0x80 nanoslp   syz-executor
 37955  518846  61916     0  3  0x10000002       0x80 nanoslp   syz-executor
 50056  374594  61916     0  3         0x2       0x80 nanoslp   syz-executor
 95468  457033  61916     0  3         0x2       0x80 nanoslp   syz-executor
   584  315026  61916     0  3         0x2       0x80 nanoslp   syz-executor
 29959  366554  61916     0  3         0x2       0x80 nanoslp   syz-executor
 92625  276284  61916     0  3         0x2       0x80 nanoslp   syz-executor
 61916  207672  44665     0  3         0x2       0x80 kqread    syz-executor
 44665  368168  76309     0  3    0x100002       0x88 sigsusp   ksh
 76309   52314  31843     0  3        0x10       0x88 kqread    sshd-session
 31843  251869  77931     0  3        0x12       0x80 kqread    sshd-session
 12156   67748      1     0  3    0x100003       0x80 ttyin     getty
 77931  323278      1     0  3           0       0x88 kqread    sshd
 21316  491250  41389    74  3   0x1100012       0x80 bpf       pflogd
 41389  326940      1     0  3           0       0x80 sbwait    pflogd
  7819  156510  65232    73  3   0x1100010       0x80 kqread    syslogd
 65232  232378      1     0  3    0x100002       0x80 sbwait    syslogd
 95096  313603      1     0  3    0x100000       0x80 kqread    resolvd
 52402  313058  25953    77  3    0x100012       0x80 kqread    dhcpleased
 64621  193008  25953    77  3    0x100012       0x80 kqread    dhcpleased
 25953  462614      1     0  3           0       0x80 kqread    dhcpleased
 11307  486772      0     0  3     0x14000      0x200 bored     smr
  3240  324798      0     0  2     0x14000      0x200           zerothread
 33501  388890      0     0  3     0x14000      0x200 aiodoned  aiodoned
 67712  254057      0     0  3     0x14000      0x200 syncer    update
 59053  495542      0     0  3     0x14000      0x200 cleaner   cleaner
 35793  292096      0     0  3     0x14000      0x200 reaper    reaper
 41084  147552      0     0  3     0x14000      0x200 pgdaemon  pagedaemon
 92695  464529      0     0  3     0x14000      0x200 bored     viomb
   436  105585      0     0  3     0x14000 0x40000200 acpi0     acpi0
 35421  180931      0     0  3     0x14000 0x40000200           idle1
 89392  186780      0     0  3     0x14000      0x200 bored     softnet1
 58200  206325      0     0  3     0x14000      0x200 bored     softnet0
 78751  170519      0     0  3     0x14000      0x200 bored     systqmp
  5092  161070      0     0  3     0x14000      0x200 bored     systq
 79914  105436      0     0  3     0x14000      0x200 tmoslp    softclockmp
 18490  117108      0     0  3     0x14000 0x40000200 tmoslp    softclock
 92942   73226      0     0  3     0x14000 0x40000200           idle0
     1  143660      0     0  3         0x2       0x80 wait      init
     0       0     -1     0  3     0x10000      0x200 scheduler swapper
ddb{1}> show all locks
Process 52940 (syz-executor) thread 0xffff800037b0aa88 (312607)
exclusive rwlock acctlk r = 0 (0xffffffff8518f338)
#0  witness_lock+0x632 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x632 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x53e sys/kern/kern_rwlock.c:320
#2  sys_acct+0x1be sys/kern/kern_acct.c:137
#3  syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#3  syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
#4  Xsyscall+0x128
exclusive kernel_lock &kernel_lock r = 1 (0xffffffff85439c00)
#0  witness_lock+0x632 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x632 sys/kern/subr_witness.c:1160
#1  syscall+0x1048 mi_syscall sys/sys/syscall_mi.h:175 [inline]
#1  syscall+0x1048 sys/arch/amd64/amd64/trap.c:783
#2  Xsyscall+0x128
ddb{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11058  12244K   12533K 166960K     12194        0
            pcb    17     24K      24K 166960K        19        0
         rtable   240     13K      13K 166960K       354        0
             pf    35     22K      22K 166960K        46        0
         ifaddr    43     12K      12K 166960K        45        0
        ifgroup    55      2K       2K 166960K        55        0
         sysctl     1      1K      13K 166960K         5        0
       counters    70     42K      42K 166960K        70        0
       ioctlops     0      0K       4K 166960K      1484        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1295     83K      83K 166960K      1379        0
      UFS quota     1     36K      36K 166960K         1        0
      UFS mount     5     44K      44K 166960K         5        0
            shm     2      2K       2K 166960K         2        0
         VM map     2      1K       1K 166960K         2        0
            sem     2      0K       0K 166960K         2        0
        dirhash    12      2K       2K 166960K        12        0
           ACPI  1734    201K     292K 166960K     11964        0
      file desc    17     61K      93K 166960K       154        0
           proc    70    128K     177K 166960K       552        0
        subproc    72      9K       9K 166960K        72        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     20K      20K 166960K         1        0
       in_multi    99      7K       7K 166960K        99        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K         2        0
    ISOFS mount     1     36K      36K 166960K         1        0
  MSDOSFS mount     1     20K      20K 166960K         1        0
           ttys    61    425K     425K 166960K        61        0
           exec     0      0K       2K 166960K       383        0
   fusefs mount     1     36K      36K 166960K         1        0
            tdb     3      1K       1K 166960K         3        0
        VM swap    14    124K     124K 166960K        15        0
       UVM amap   236    244K     264K 166960K      3273        0
       UVM aobj     4      4K       4K 166960K         4        0
     pinsyscall  1066   1722K    1727K 166960K      1313        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K         2        0
            NDP    18      0K       1K 166960K        28        0
           temp    34   9166K    9176K 166960K      3904        0
         kqueue    18     48K      48K 166960K        32        0
      SYN cache     2     16K      16K 166960K         2        0
ddb{1}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache    128       28    0        0     1     0     1     1     0     8    0
rtpcb      120       33    0       30     1     0     1     1     0     8    0
rtentry    176      111    0        1     5     0     5     5     0     8    0
unpcb      144       46    0       29     1     0     1     1     0     8    0
syncache   336        4    0        4     1     0     1     1     0     8    1
tcpcb      736        8    0        4     1     0     1     1     0     8    0
arp        136       18    0        0     1     0     1     1     0     8    0
inpcb      328       72    0       65     1     0     1     1     0     8    0
nd6        152       24    0        0     1     0     1     1     0     8    0
kcovpl      48        8    0        0     1     0     1     1     0     8    0
pffrag     232        2    0        1     1     0     1     1     0   482    0
pffrnode    88        2    0        1     1     0     1     1     0     8    0
pffrent     40        3    0        2     1     0     1     1     0     8    0
pfosfp      40     1428    0     1005     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfrktable  1344       1    0        0     1     0     1     1     0     8    0
pfstitem    24       21    0        0     1     0     1     1     0     8    0
pfstkey    128       21    0        0     1     0     1     1     0     8    0
pfstate    448       21    0        0     3     0     3     3     0     8    0
pfrule     1360      22    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      452    0        0    29     0    29    29     0     8    0
art_table   40      453    0        0     5     0     5     5     0     8    0
art_node    32      111    0       11     1     0     1     1     0     8    0
shmpl      112        1    0        0     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1591    0      121    92     0    92    92     0     8    0
ffsino     296     1591    0      121   114     0   114   114     0     8    0
nchpl      144     1809    0      105    64     0    64    64     0     8    0
vnodes     216     1691    0        0    94     0    94    94     0     8    0
namei      1024    5539    0     5539     1     0     1     1     0     8    1
percpumem   16       51    0        0     1     0     1     1     0     8    0
kstatmem   264       27    0        0     2     0     2     2     0     8    0
scxspl     216     6676    0     6676     4     3     1     3     1     8    1
plimitpl   152       30    0       12     1     0     1     1     0     8    0
sigapl     424      473    0      424     7     0     7     7     0     8    0
knotepl    120       57    0        0     2     0     2     2     0     8    0
kqueuepl   224       32    0       18     1     0     1     1     0     8    0
pipepl     344      126    0       99     3     0     3     3     0     8    0
fdescpl    528      456    0      425     3     0     3     3     0     8    0
filepl     160     1643    0     1416    10     0    10    10     0     8    0
lockfpl    104       12    0       10     1     0     1     1     0     8    0
lockfspl    48        7    0        5     1     0     1     1     0     8    0
sessionpl  144       25    0       15     1     0     1     1     0     8    0
pgrppl      48       33    0       15     1     0     1     1     0     8    0
ucredpl    104      114    0      101     1     0     1     1     0     8    0
zombiepl   144      427    0      424     1     0     1     1     0     8    0
processpl  1232     473    0      424     5     0     5     5     0     8    1
procpl     664      508    0      448     6     0     6     6     0     8    0
sockpl     752      151    0      124     4     0     4     4     0     8    1
mcl64k     65536      4    0        0     1     0     1     1     0     8    0
mcl16k     16384      3    0        0     1     0     1     1     0     8    0
mcl12k     12288      2    0        0     1     0     1     1     0     8    0
mcl9k128   9344       2    0        0     1     0     1     1     0     8    0
mcl8k      8192       3    0        0     1     0     1     1     0     8    0
mcl4k      4096     117    0        0    15     0    15    15     0     8    0
mcl2k      2048      12    0        0     2     0     2     2     0     8    0
mextrefs    64       12    0        0     1     0     1     1     0     8    0
mtagpl      96        3    0        0     1     0     1     1     0     8    0
mbufpl     256      137    0        0     9     0     9     9     0     8    0
bufpl      272     2347    0      106   150     0   150   150     0     8    0
anonpl      32     3811    0        0    31     0    31    31     0   222    0
amapchunkpl 152    8971    0     8472    21     0    21    21     0   158    0
amappl16   200     1857    0     1829     5     2     3     5     0     8    0
amappl15   192        1    0        1     1     1     0     1     0     8    0
amappl14   184      441    0      440     1     0     1     1     0     8    0
amappl13   176      125    0      113     1     0     1     1     0     8    0
amappl12   168      710    0      678     2     0     2     2     0     8    0
amappl11   160        6    0        6     2     2     0     1     0     8    0
amappl10   152       79    0       65     1     0     1     1     0     8    0
amappl9    144      277    0      277     1     1     0     1     0     8    0
amappl8    136      105    0      103     1     0     1     1     0     8    0
amappl7    128      151    0      137     1     0     1     1     0     8    0
amappl6    120      158    0      157     1     0     1     1     0     8    0
amappl5    112      100    0       90     1     0     1     1     0     8    0
amappl4    104      309    0      289     1     0     1     1     0     8    0
amappl3     96     1527    0     1428     3     0     3     3     0     8    0
amappl2     88      580    0      500     2     0     2     2     0     8    0
amappl1     80    10534    0     9933    15     0    15    15     0     8    0
amappl      88     2549    0     2384     4     0     4     4     0    92    0
uvmvnodes   80       98    0        0     2     0     2     2     0     8    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       1    0        0     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        6    0        6     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        3    0        0     1     0     1     1     0     8    0
uaddrrnd    24      456    0      425     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      456    0      425     1     0     1     1     0     8    0
vmmpekpl   168     5788    0     5755     2     0     2     2     0     8    0
vmmpepl    168    38692    0    36777    87     0    87    87     0   357    0
vmsppl     488      455    0      425     5     0     5     5     0     8    1
rwobjpl     80    14792    0    13761    24     0    24    24     0     8    2
pdppl      4096     921    0      850   103    18    85    87     0     8   14
pvpl        32    13760    0        0   111     0   111   111     0   265    0
pmappl     256      455    0      425     3     0     3     3     0     8    0
extentpl    40       47    0       29     1     0     1     1     0     8    0
phpool     120      421    0       21    13     0    13    13     0     8    0
ddb{1}> machine ddbcpu 0
Stopped at      x86_ipi_db+0x19:        leave
x86_ipi_db(ffffffff850daff0) at x86_ipi_db+0x19 sys/arch/amd64/amd64/db_interface.c:412
x86_ipi_handler() at x86_ipi_handler+0x112 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff85439400) at __mp_lock+0x272 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff85439400) at __mp_lock+0x272 sys/kern/kern_lock.c:173
softintr_dispatch(0) at softintr_dispatch+0x215 sys/kern/kern_softintr.c:83
dosoftint(0) at dosoftint+0x7b sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
end of kernel
end trace frame: 0x7c8220e0bd40, count: 8
ddb{0}> trace
x86_ipi_db(ffffffff850daff0) at x86_ipi_db+0x19 sys/arch/amd64/amd64/db_interface.c:412
x86_ipi_handler() at x86_ipi_handler+0x112 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff85439400) at __mp_lock+0x272 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff85439400) at __mp_lock+0x272 sys/kern/kern_lock.c:173
softintr_dispatch(0) at softintr_dispatch+0x215 sys/kern/kern_softintr.c:83
dosoftint(0) at dosoftint+0x7b sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
end of kernel
end trace frame: 0x7c8220e0bd40, count: -7
ddb{0}> machine ddbcpu 1
Stopped at      db_enter+0x17:  popq    %rbp
db_enter() at db_enter+0x17 sys/arch/amd64/amd64/db_interface.c:457
panic(ffffffff846414f3) at panic+0x270 sys/kern/subr_prf.c:198
__asan_load2_noabort(ffff800001b59652) at __asan_load2_noabort+0x107
knote_processfork(ffffffff85423320,5eca) at knote_processfork+0x603 sys/kern/kern_event.c:2289
fork1(ffffffff85422fc0,f0,ffffffff82b481d0,0,0,ffff800036af8720) at fork1+0x1225 sys/kern/kern_fork.c:511
kthread_create(ffffffff82b481d0,0,ffffffff85d6daa0,ffffffff84b32660) at kthread_create+0xa8 sys/kern/kern_kthread.c:61
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e acct_start sys/kern/kern_acct.c:300 [inline]
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e sys/kern/kern_acct.c:151
syscall(ffff800036af8af0) at syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036af8af0) at syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x88d2c7e4090, count: 6
ddb{1}> trace
db_enter() at db_enter+0x17 sys/arch/amd64/amd64/db_interface.c:457
panic(ffffffff846414f3) at panic+0x270 sys/kern/subr_prf.c:198
__asan_load2_noabort(ffff800001b59652) at __asan_load2_noabort+0x107
knote_processfork(ffffffff85423320,5eca) at knote_processfork+0x603 sys/kern/kern_event.c:2289
fork1(ffffffff85422fc0,f0,ffffffff82b481d0,0,0,ffff800036af8720) at fork1+0x1225 sys/kern/kern_fork.c:511
kthread_create(ffffffff82b481d0,0,ffffffff85d6daa0,ffffffff84b32660) at kthread_create+0xa8 sys/kern/kern_kthread.c:61
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e acct_start sys/kern/kern_acct.c:300 [inline]
sys_acct(ffff800037b0aa88,ffff800036af8af0,ffff800036af8a60) at sys_acct+0x35e sys/kern/kern_acct.c:151
syscall(ffff800036af8af0) at syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800036af8af0) at syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x88d2c7e4090, count: -9

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/14 16:36 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan f02e55361321 6f9b3e89 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan KASAN: invalid memory access in knote_processfork
2026/08/14 14:23 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan 3be50a05e816 6f9b3e89 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan KASAN: invalid memory access in knote_processfork
2026/08/14 10:22 https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan 3be50a05e816 6f9b3e89 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-kasan KASAN: invalid memory access in knote_processfork
* Struck through repros no longer work on HEAD.