login: panic: kernel diagnostic assertion "atomic_load_int(&fdp->fd_nuserevents) == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_descrip.c", line 1219
Stopped at db_enter+0x25: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
197960 70010 32767 0x10 0x4000000 0 syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834459a2) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348588a,ffffffff8345eeed,4c3,ffffffff83419fcd) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff800031fb1778) at fdfree+0x349
exit1(ffff800031fb1778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff800031fb1778,ffff80003c4084c0,ffff80003c408410) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c4084c0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4084c0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71ab251b4570, count: 7
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{1}>
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: kernel diagnostic assertion "atomic_load_int(&fdp->fd_nuserevents) == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_descrip.c", line 1219
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834459a2) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348588a,ffffffff8345eeed,4c3,ffffffff83419fcd) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff800031fb1778) at fdfree+0x349
exit1(ffff800031fb1778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff800031fb1778,ffff80003c4084c0,ffff80003c408410) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c4084c0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4084c0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71ab251b4570, count: -8
ddb{1}> show registers
rdi 0
rsi 0x1
rbp 0xffff80003c408200
rbx 0xffff8000299bee07
rdx 0
rcx 0xffff800031fb1778
rax 0xffff8000299bdff0
r8 0x101010101010101
r9 0x8080808080808080
r10 0xfc0c5adca741d6e6
r11 0xec0d7b8fd2d433d
r12 0xffff8000299bec08
r13 0
r14 0
r15 0x1
rip 0xffffffff814213f5 db_enter+0x25
cs 0x8
rflags 0x246
rsp 0xffff80003c4081f0
ss 0x10
db_enter+0x25: addq $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor) tid=159527 pid=43916 tcnt=0 stat=onproc
flags process=1018<EXITING,SUGID,SINGLEEXIT> proc=2000<WEXIT>
runpri=32, usrpri=86, slppri=32, nice=20
wchan=0x0, wmesg=, ps_single=0xffff800031fb1778 scnt=-1 ecnt=1
forw=0xffffffffffffffff, list=0xffff8000fffef4d8,0xffff800031fb1258
process=0xffff8000fffe7510 user=0xffff80003c403000, vmspace=0xfffffd800f8a7028
estcpu=36, cpticks=3, pctcpu=0.0, user=0, sys=1, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
86571 470062 69395 32767 2 0x10 syz-executor
70010 187131 63453 32767 2 0x10 syz-executor
70010 197960 63453 32767 7 0x4000010 syz-executor
45678 347004 31345 32767 3 0x90 nanoslp syz-executor
45678 13416 31345 32767 3 0x4000090 sbwait syz-executor
45678 143362 31345 32767 3 0x4000090 fsleep syz-executor
39521 115229 44625 32767 3 0x90 nanoslp syz-executor
39521 522603 44625 32767 3 0x4000090 kqsel syz-executor
39521 502905 44625 32767 3 0x4000090 fsleep syz-executor
90464 176796 86370 0 3 0x100082 sbwait arp
86370 302193 96638 0 3 0x10008a sigsusp sh
69395 449909 81068 32767 3 0x90 nanoslp syz-executor
65423 289441 24755 32767 3 0x90 nanoslp syz-executor
60420 132164 20796 32767 3 0x90 nanoslp syz-executor
31345 338959 38340 32767 3 0x90 nanoslp syz-executor
44625 406036 89983 32767 3 0x90 nanoslp syz-executor
63453 426076 34786 32767 3 0x90 nanoslp syz-executor
96638 275228 35167 0 3 0x80 wait syz-executor
68263 63597 76402 32767 3 0x90 wait syz-executor
81068 353873 41631 0 3 0x82 wait syz-executor
24755 39835 41631 0 3 0x82 wait syz-executor
38340 303308 41631 0 3 0x82 wait syz-executor
20796 209171 41631 0 3 0x82 wait syz-executor
89983 219557 41631 0 3 0x82 wait syz-executor
35167 151528 41631 0 3 0x82 wait syz-executor
34786 204880 41631 0 3 0x82 wait syz-executor
76402 15702 41631 0 3 0x82 wait syz-executor
41631 45472 78187 0 3 0x82 kqread syz-executor
78187 110815 46867 0 3 0x10008a sigsusp ksh
46867 110273 62969 0 3 0x98 kqread sshd-session
62969 23144 90334 0 3 0x92 kqread sshd-session
98222 331208 1 0 3 0x100083 ttyin getty
90334 73122 1 0 3 0x88 kqread sshd
12625 455198 83214 73 3 0x1100090 kqread syslogd
83214 348930 1 0 3 0x100082 sbwait syslogd
41666 427387 1 0 3 0x100080 kqread resolvd
68416 420525 68893 77 3 0x100092 kqread dhcpleased
31601 280489 68893 77 3 0x100092 kqread dhcpleased
68893 155764 1 0 3 0x80 kqread dhcpleased
71124 315397 0 0 3 0x14200 bored smr
17560 416202 0 0 3 0x14200 pgzero zerothread
96949 134560 0 0 3 0x14200 aiodoned aiodoned
46417 172714 0 0 3 0x14200 syncer update
24072 466258 0 0 3 0x14200 cleaner cleaner
81801 200858 0 0 3 0x14200 reaper reaper
46810 289357 0 0 3 0x14200 pgdaemon pagedaemon
1492 140870 0 0 3 0x14200 bored viomb
55105 363234 0 0 3 0x40014200 acpi0 acpi0
81425 19180 0 0 3 0x40014200 idle1
25319 103552 0 0 3 0x14200 bored softnet1
24117 128623 0 0 3 0x14200 bored softnet0
74501 502694 0 0 3 0x14200 bored systqmp
76600 33843 0 0 3 0x14200 bored systq
83090 458581 0 0 3 0x14200 tmoslp softclockmp
89667 75550 0 0 3 0x40014200 tmoslp softclock
23854 470957 0 0 3 0x40014200 idle0
1 489502 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 11056 12019K 12034K 166960K 12147 0
pcb 17 12K 12K 166960K 17 0
rtable 227 6K 7K 166960K 410 0
pf 31 16K 16K 166960K 31 0
ifaddr 40 7K 7K 166960K 42 0
ifgroup 50 2K 2K 166960K 50 0
sysctl 4 1K 9K 166960K 9 0
counters 70 37K 37K 166960K 70 0
ioctlops 0 0K 2K 166960K 33 0
iov 0 0K 16K 166960K 16 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1288 81K 81K 166960K 1377 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 8 0
VM map 2 1K 1K 166960K 2 0
sem 12 0K 0K 166960K 20 0
dirhash 12 2K 2K 166960K 21 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 26 97K 125K 166960K 468 0
sigio 0 0K 0K 166960K 8 0
proc 58 99K 131K 166960K 526 0
subproc 72 4K 4K 166960K 72 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 2 0K 0K 166960K 68 0
in_multi 89 6K 6K 166960K 103 0
ether_multi 1 0K 0K 166960K 3 0
mrt 0 0K 0K 166960K 14 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 79 360K 360K 166960K 79 0
exec 0 0K 1K 166960K 375 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 259 154K 168K 166960K 5934 0
UVM aobj 12 4K 4K 166960K 14 0
pinsyscall 49 98K 113K 166960K 1525 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 39 0
NDP 11 0K 1K 166960K 25 0
temp 44 9077K 9140K 166960K 6179 0
kqueue 15 20K 30K 166960K 93 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 26 0 0 1 0 1 1 0 8 0
rtpcb 120 60 0 56 1 0 1 1 0 8 0
rtentry 176 112 0 7 5 0 5 5 0 8 0
unpcb 144 257 0 240 1 0 1 1 0 8 0
syncache 336 4 0 4 2 1 1 1 0 8 1
tcpcb 736 146 0 142 1 0 1 1 0 8 0
arp 136 18 0 0 1 0 1 1 0 8 0
ipq 40 2 0 1 1 0 1 1 0 8 0
ipqe 40 4 0 3 1 0 1 1 0 8 0
inpcb 328 366 0 357 2 0 2 2 0 8 0
ip6q 72 3 0 1 1 0 1 1 0 8 0
ip6af 40 8 0 2 1 0 1 1 0 8 0
nd6 152 29 0 6 1 0 1 1 0 8 0
kcovpl 48 8 0 0 1 0 1 1 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 425 0 9 27 0 27 27 0 8 0
art_table 40 426 0 9 5 0 5 5 0 8 0
art_node 32 112 0 16 1 0 1 1 0 8 0
sysvmsgpl 40 3 0 3 1 0 1 1 0 8 1
semupl 112 1 0 1 1 0 1 1 0 8 1
semapl 112 18 0 8 1 0 1 1 0 8 0
shmpl 112 11 0 2 1 0 1 1 0 8 0
dirhash 1024 23 0 6 3 0 3 3 0 8 0
dino2pl 256 2051 0 588 93 0 93 93 0 8 0
ffsino 296 2051 0 588 114 0 114 114 0 8 0
nchpl 144 2707 0 1018 63 0 63 63 0 8 0
vnodes 216 2132 0 0 119 0 119 119 0 8 0
namei 1024 8233 0 8233 1 0 1 1 0 8 1
percpumem 16 50 0 0 1 0 1 1 0 8 0
kstatmem 264 24 0 0 2 0 2 2 0 8 0
scxspl 216 9735 0 9735 9 1 8 8 1 8 8
plimitpl 152 94 0 70 2 0 2 2 0 8 1
sigapl 424 756 0 701 7 0 7 7 0 8 0
knotepl 120 534 0 0 17 0 17 17 0 8 0
kqueuepl 224 123 0 112 1 0 1 1 0 8 0
pipepl 344 148 0 120 3 0 3 3 0 8 0
fdescpl 528 740 0 701 4 0 4 4 0 8 0
filepl 160 3443 0 3226 12 0 12 12 0 8 1
lockfpl 104 99 0 97 1 0 1 1 0 8 0
lockfspl 48 35 0 33 1 0 1 1 0 8 0
sessionpl 144 22 0 6 1 0 1 1 0 8 0
pgrppl 48 42 0 18 1 0 1 1 0 8 0
ucredpl 104 513 0 495 1 0 1 1 0 8 0
zombiepl 144 704 0 701 1 0 1 1 0 8 0
processpl 1232 756 0 701 5 0 5 5 0 8 0
procpl 664 1369 0 1309 7 0 7 7 0 8 1
sosppl 176 4 0 4 1 0 1 1 0 8 1
sockpl 752 685 0 655 5 0 5 5 0 8 0
mcl64k 65536 2 0 0 1 0 1 1 0 8 0
mcl16k 16384 2 0 0 1 0 1 1 0 8 0
mcl8k 8192 4 0 0 1 0 1 1 0 8 0
mcl4k 4096 113 0 0 15 0 15 15 0 8 0
mcl2k2 2112 1 0 0 1 0 1 1 0 8 0
mcl2k 2048 33 0 0 5 0 5 5 0 8 0
mtagpl 96 1 0 0 1 0 1 1 0 8 0
mbufpl 256 277 0 0 18 0 18 18 0 8 0
bufpl 280 3204 0 113 221 0 221 221 0 8 0
anonpl 32 7765 0 0 63 0 63 63 0 246 0
amapchunkpl 152 18974 0 18402 32 0 32 32 0 158 7
amappl16 200 2717 0 2690 16 3 13 14 0 8 8
amappl15 192 9 0 9 1 1 0 1 0 8 0
amappl14 184 400 0 398 1 0 1 1 0 8 0
amappl13 176 114 0 103 1 0 1 1 0 8 0
amappl12 168 969 0 933 2 0 2 2 0 8 0
amappl11 160 71 0 71 1 1 0 1 0 8 0
amappl10 152 62 0 52 1 0 1 1 0 8 0
amappl9 144 257 0 257 1 1 0 1 0 8 0
amappl8 136 95 0 92 1 0 1 1 0 8 0
amappl7 128 42 0 40 1 0 1 1 0 8 0
amappl6 120 248 0 235 1 0 1 1 0 8 0
amappl5 112 80 0 74 1 0 1 1 0 8 0
amappl4 104 455 0 422 3 1 2 2 0 8 1
amappl3 96 3171 0 3072 3 0 3 3 0 8 0
amappl2 88 809 0 738 2 0 2 2 0 8 0
amappl1 80 10377 0 9791 15 1 14 14 0 8 0
amappl 88 5225 0 5034 5 0 5 5 0 92 0
uvmvnodes 80 112 0 0 3 0 3 3 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 13 0 2 1 0 1 1 0 8 0
uaddrrnd 24 740 0 701 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 740 0 701 1 0 1 1 0 8 0
vmmpekpl 168 7456 0 7421 2 0 2 2 0 8 0
vmmpepl 168 53959 0 51820 101 0 101 101 0 357 2
vmsppl 488 739 0 701 6 0 6 6 0 8 0
rwobjpl 80 17640 0 16625 26 0 26 26 0 8 3
pdppl 4096 1487 0 1402 115 28 87 97 0 8 2
pvpl 32 14061 0 0 114 0 114 114 0 265 0
pmappl 256 739 0 701 3 0 3 3 0 8 0
extentpl 40 45 0 27 1 0 1 1 0 8 0
phpool 112 290 0 31 8 0 8 8 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
x86_ipi_db(ffffffff83908ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83
dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
sysctl_file(ffff80003c40e958,4,9999999999999999,ffff80003c40e988,ffff800031fb1a10) at sysctl_file+0x2d20 sys/kern/kern_sysctl.c:1791
kern_sysctl(ffff80003c40e954,5,9999999999999999,ffff80003c40e988,0,ffffffc9,9cc172af9b661c8b) at kern_sysctl+0x139 sys/kern/kern_sysctl.c:734
sys_sysctl(ffff800031fb1a10,ffff80003c40eac0,ffff80003c40ea10) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80003c40eac0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c40eac0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xcf69e973410, count: 2
ddb{0}> trace
x86_ipi_db(ffffffff83908ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83
dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a91d80) at __mp_lock+0x192 sys/kern/kern_lock.c:173
sysctl_file(ffff80003c40e958,4,9999999999999999,ffff80003c40e988,ffff800031fb1a10) at sysctl_file+0x2d20 sys/kern/kern_sysctl.c:1791
kern_sysctl(ffff80003c40e954,5,9999999999999999,ffff80003c40e988,0,ffffffc9,9cc172af9b661c8b) at kern_sysctl+0x139 sys/kern/kern_sysctl.c:734
sys_sysctl(ffff800031fb1a10,ffff80003c40eac0,ffff80003c40ea10) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80003c40eac0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c40eac0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xcf69e973410, count: -13
ddb{0}> machine ddbcpu 1
Stopped at db_enter+0x25: addq $0x8,%rsp
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834459a2) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348588a,ffffffff8345eeed,4c3,ffffffff83419fcd) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff800031fb1778) at fdfree+0x349
exit1(ffff800031fb1778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff800031fb1778,ffff80003c4084c0,ffff80003c408410) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c4084c0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4084c0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71ab251b4570, count: 7
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834459a2) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348588a,ffffffff8345eeed,4c3,ffffffff83419fcd) at __assert+0x29 sys/kern/subr_prf.c:-1
fdfree(ffff800031fb1778) at fdfree+0x349
exit1(ffff800031fb1778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff800031fb1778,ffff80003c4084c0,ffff80003c408410) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c4084c0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4084c0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71ab251b4570, count: -8