assert "(TAILQ_NEXT(inp, inp_queue) == NULL) || (TAILQ_NEXT(inp, inp_queue) == _Q_INVALID)" failed in in_pcb.c

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2de8940ea18f fpurge() first appeared in 4.3BSD-Reno ok der..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=16b93682580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1bc15e68cd2a49e5
dashboard link: https://syzkaller.appspot.com/bug?extid=05b4b109c890334897af

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f380569e7f87/disk-2de8940e.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/5842a28abfb0/bsd-2de8940e.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a8a2528ab6c1/kernel-2de8940e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+05b4b1...@syzkaller.appspotmail.com

panic: kernel diagnostic assertion "(TAILQ_NEXT(inp, inp_queue) == NULL) || (TAILQ_NEXT(inp, inp_queue) == _Q_INVALID)" failed: file "/syzkaller/managers/main/kernel/sys/netinet/in_pcb.c", line 673
Starting stack trace...
panic(ffffffff8342cfde) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff833df4e4,ffffffff833caf1a,2a1,ffffffff833a396f) at __assert+0x29 sys/kern/subr_prf.c:-1
in_pcbunref(fffffd80715647b0) at in_pcbunref+0x206 sys/netinet/in_pcb.c:672
tcp_input_solocked(ffff80002a74b640,ffff80002a74b64c,0,2,ffff80002a74b638) at tcp_input_solocked+0xfd sys/netinet/tcp_input.c:2229
tcp_input_mlist(ffffffff838ebd20,2) at tcp_input_mlist+0x93 sys/netinet/tcp_input.c:-1
if_input_process(ffff800000b11800,ffff80002a74b718,0) at if_input_process+0x229 sys/net/if.c:1015
ifiq_process(ffff800000b11c18) at ifiq_process+0xcd sys/net/ifq.c:874
taskq_thread(ffff80000002c000) at taskq_thread+0xd4 sys/kern/kern_task.c:446
end trace frame: 0x0, count: 249
End of stack trace.
syncing disks...40 37 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 giving up


OpenBSD/amd64 (Amnesiac) (tty00)

login: WARNING: SPL NOT LOWERED ON SYSCALL 3 3 EXIT 0 3
Stopped at savectx+0xae: movl $0,%gs:0x688
TID PID UID PRFLAGS PFLAGS CPU COMMAND
*113070 78167 0 0x2 0 0 syz-executor
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72adb68f8c80, count: 14
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> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 10212 11142K 11933K 166960K 15800 0
pcb 17 16K 17K 166960K 560 0
rtable 192 8K 9K 166960K 917 0
pf 29 12K 21K 166960K 189 0
ifaddr 35 6K 8K 166960K 146 0
ifgroup 46 2K 2K 166960K 240 0
sysctl 4 1K 9K 166960K 17 0
counters 31 17K 18K 166960K 129 0
ioctlops 0 0K 4K 166960K 465 0
iov 0 0K 16K 166960K 313 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1471 92K 93K 166960K 3811 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 23 0
VM map 2 1K 1K 166960K 2 0
sem 12 0K 0K 166960K 236 0
dirhash 12 2K 2K 166960K 30 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 17 61K 97K 166960K 2355 0
sigio 0 0K 0K 166960K 29 0
proc 60 59K 124K 166960K 870 0
subproc 72 4K 4K 166960K 137 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 0 0K 0K 166960K 318 0
in_multi 76 5K 7K 166960K 255 0
ether_multi 1 0K 0K 166960K 16 0
mrt 0 0K 0K 166960K 23 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 259 1155K 1155K 166960K 259 0
exec 0 0K 2K 166960K 886 0
fusefs mount 1 32K 32K 166960K 1 0
pfkey data 0 0K 0K 166960K 12 0
tdb 3 0K 0K 166960K 3 0
VM swap 8 62K 64K 166960K 10 0
UVM amap 242 152K 180K 166960K 21518 0
UVM aobj 131 8K 8K 166960K 133 0
pinsyscall 38 76K 96K 166960K 3582 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 132 0
NDP 10 0K 2K 166960K 103 0
temp 77 8688K 8931K 166960K 111582 0
kqueue 16 26K 32K 166960K 361 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 120 178 0 175 1 0 1 1 0 8 0
rtentry 136 296 0 215 4 0 4 4 0 8 0
unpcb 144 1601 0 1583 9 3 6 6 0 8 5
syncache 336 9 0 9 2 1 1 1 0 8 1
tcpqe 32 3 0 3 1 0 1 1 0 8 1
tcpcb 736 613 0 602 8 1 7 7 0 8 5
arp 88 33 0 20 1 0 1 1 0 8 0
ipq 40 7 0 2 1 0 1 1 0 8 0
ipqe 40 9 0 4 1 0 1 1 0 8 0
inpcb 328 2659 0 2642 16 6 10 10 0 8 8
ip6q 72 5 0 3 1 0 1 1 0 8 0
ip6af 40 9 0 6 2 1 1 1 0 8 0
nd6 104 55 0 35 1 0 1 1 0 8 0
pkpcb 40 122 0 122 2 1 1 1 0 8 1
kcovpl 48 15 0 7 1 0 1 1 0 8 0
ppxss 1072 71 0 71 2 1 1 1 0 8 1
pppxif 1384 13 0 13 2 1 1 1 0 8 1
pfrule 1344 1 0 1 1 1 0 1 0 8 0
rttmr 136 5 0 5 1 0 1 1 0 8 1
art_heap8 4096 3 0 0 3 0 3 3 0 8 0
art_heap4 256 1186 0 805 32 3 29 29 0 8 5
art_table 32 1189 0 805 4 0 4 4 0 8 0
art_node 16 224 0 153 1 0 1 1 0 8 0
sysvmsgpl 40 10 0 5 1 0 1 1 0 8 0
semupl 112 3 0 3 2 1 1 1 0 8 1
semapl 112 232 0 222 1 0 1 1 0 8 0
shmpl 112 130 0 2 4 0 4 4 0 8 0
dirhash 1024 29 0 12 3 0 3 3 0 8 0
dino2pl 256 5510 0 4000 95 0 95 95 0 8 0
ffsino 248 5510 0 4000 95 0 95 95 0 8 0
nchpl 144 8721 0 8118 63 33 30 63 0 8 7
rtmask 32 10 0 10 2 1 1 1 0 8 1
uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0
vnodes 216 5926 0 0 330 0 330 330 0 8 0
namei 1024 31140 0 31139 2 1 1 2 0 8 0
kstatmem 264 140 0 120 2 0 2 2 0 8 0
acpiwqpl 32 2 0 2 1 0 1 1 1 8 1
scsiplug 72 7 0 7 2 1 1 1 0 8 1
scxspl 216 26045 0 26043 10 2 8 8 1 8 7
plimitpl 152 570 0 554 1 0 1 1 0 8 0
sigapl 424 2649 0 2603 9 1 8 8 0 8 1
knotepl 120 679333 0 679041 57 34 23 23 0 8 13
kqueuepl 184 657 0 643 4 2 2 3 0 8 1
pipepl 296 352 0 325 5 0 5 5 0 8 2
fdescpl 440 2607 0 2578 5 1 4 5 0 8 0
filepl 120 17319 0 17097 20 7 13 15 0 8 5
lockfpl 104 1468 0 1466 1 0 1 1 0 8 0
lockfspl 48 610 0 608 1 0 1 1 0 8 0
sessionpl 144 33 0 25 1 0 1 1 0 8 0
pgrppl 48 71 0 55 1 0 1 1 0 8 0
ucredpl 104 2977 0 2964 1 0 1 1 0 8 0
zombiepl 144 2603 0 2603 2 1 1 1 0 8 1
processpl 1160 2649 0 2603 5 0 5 5 0 8 0
procpl 656 5575 0 5516 9 1 8 8 0 8 0
sosppl 168 16 0 16 2 1 1 1 0 8 1
sockpl 528 4628 0 4588 19 8 11 14 0 8 8
mcl64k 65536 54 0 54 2 1 1 1 0 8 1
mcl16k 16384 39 0 39 2 1 1 1 0 8 1
mcl12k 12288 7 0 7 2 1 1 1 0 8 1
mcl9k 9216 3 0 3 1 0 1 1 0 8 1
mcl8k 8192 45 0 44 2 1 1 1 0 8 0
mcl4k 4096 5473 0 5415 15 6 9 13 0 8 1
mcl2k2 2112 37 0 37 2 1 1 1 0 8 1
mcl2k 2048 2480 0 2473 6 3 3 4 0 8 1
mtagpl 96 269 0 146 5 0 5 5 0 8 1
mbufpl 256 28386 0 28129 37 7 30 32 0 8 8
bufpl 280 6371 0 144 445 0 445 445 0 8 0
anonpl 24 353179 0 341752 100 4 96 96 0 187 0
amapchunkpl 152 74051 0 73459 44 9 35 35 0 158 10
amappl16 200 7759 0 7318 42 5 37 37 0 8 0
amappl15 192 7 0 6 1 0 1 1 0 8 0
amappl14 184 127 0 117 1 0 1 1 0 8 0
amappl13 176 9 0 9 2 1 1 1 0 8 1
amappl12 168 3322 0 3293 3 1 2 3 0 8 0
amappl11 160 49 0 39 1 0 1 1 0 8 0
amappl10 152 3 0 3 1 1 0 1 0 8 0
amappl9 144 251 0 251 1 1 0 1 0 8 0
amappl8 136 23 0 21 1 0 1 1 0 8 0
amappl7 128 118 0 107 1 0 1 1 0 8 0
amappl6 120 241 0 237 1 0 1 1 0 8 0
amappl5 112 144 0 137 1 0 1 1 0 8 0
amappl4 104 314 0 297 1 0 1 1 0 8 0
amappl3 96 15175 0 15065 5 1 4 4 0 8 0
amappl2 88 737 0 679 2 0 2 2 0 8 0
amappl1 80 17741 0 17194 14 1 13 13 0 8 0
amappl 88 20304 0 20127 5 0 5 5 0 92 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 39 0 39 2 1 1 1 0 8 1
dma128 128 260 0 260 2 1 1 1 0 8 1
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 72 132 0 2 3 0 3 3 0 8 0
uaddrrnd 24 2607 0 2578 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 2607 0 2578 1 0 1 1 0 8 0
vmmpekpl 168 17524 0 17463 3 0 3 3 0 8 0
vmmpepl 168 165136 0 162839 122 2 120 120 0 357 6
vmsppl 360 2606 0 2578 4 1 3 4 0 8 0
rwobjpl 32 45434 0 38102 62 0 62 62 0 8 0
pdppl 4096 5220 0 5156 114 48 66 82 0 8 2
pvpl 32 1085909 0 1068696 212 16 196 196 0 265 19
pmappl 216 2606 0 2578 3 0 3 3 0 8 1
extentpl 40 45 0 27 1 0 1 1 0 8 0
phpool 112 327 0 75 8 0 8 8 0 8 0
ddb> machine ddbcpu 0
No such command
ddb> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72adb68f8c80, count: -1
ddb> machine ddbcpu 1
No such command
ddb> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72adb68f8c80, count: -1


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