panic: pool_p_free: mbufpl free list modified: page ADDR; item addr ADDR; offset 0x0=ADDR

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syzbot

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Dec 5, 2019, 11:31:08 AM12/5/19
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Hello,

syzbot found the following crash on:

HEAD commit: 73401542 When we detect that a resolver strategy is not va..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=16e32e41e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d0fe83f82fe104d4
dashboard link: https://syzkaller.appspot.com/bug?extid=3d0d075a1cfb243d7548

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3d0d07...@syzkaller.appspotmail.com

panic: pool_p_free: mbufpl free list modified: page 0xfffffd802ed38000;
item addr 0xfffffd802ed38000; offset 0x0=0x929b780000000000
Stopped at db_enter+0x18: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
*240192 12217 0 0x14000 0x200 0 systqmp
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic(ffffffff821fe5cf) at panic+0x15c sys/kern/subr_prf.c:207
pool_p_free(ffffffff8253d850,fffffd802dfd2560) at pool_p_free+0x1de
sys/kern/subr_pool.c:991
pool_gc_pages(0) at pool_gc_pages+0x225 sys/kern/subr_pool.c:1586
taskq_thread(ffffffff82475140) at taskq_thread+0x52 sys/kern/kern_task.c:369
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
pool_p_free: mbufpl free list modified: page 0xfffffd802ed38000; item addr
0xfffffd802ed38000; offset 0x0=0x929b780000000000
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic(ffffffff821fe5cf) at panic+0x15c sys/kern/subr_prf.c:207
pool_p_free(ffffffff8253d850,fffffd802dfd2560) at pool_p_free+0x1de
sys/kern/subr_pool.c:991
pool_gc_pages(0) at pool_gc_pages+0x225 sys/kern/subr_pool.c:1586
taskq_thread(ffffffff82475140) at taskq_thread+0x52 sys/kern/kern_task.c:369
end trace frame: 0x0, count: -5
ddb> show registers
rdi 0
rsi 0x1
rbp 0xffff80001482e850
rbx 0xffff80001482e900
rdx 0x2
rcx 0
rax 0
r8 0xffff80001482e810
r9 0x1
r10 0
r11 0x83ae71b6dad62b30
r12 0x3000000008
r13 0xffff80001482e860
r14 0x100
r15 0x1
rip 0xffffffff81933778 db_enter+0x18
cs 0x8
rflags 0x246
rsp 0xffff80001482e840
ss 0x10
db_enter+0x18: addq $0x8,%rsp
ddb> show proc
PROC (systqmp) pid=240192 stat=onproc
flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>
pri=32, usrpri=51, nice=20
forw=0xffffffffffffffff, list=0xffff8000ffffeed0,0xffff8000ffffe500
process=0xffff8000ffffc000 user=0xffff800014829000,
vmspace=0xffffffff8253bfc8
estcpu=1, cpticks=1, pctcpu=0.0
user=0, sys=1, intr=0
ddb> ps
PID TID PPID UID S FLAGS WAIT COMMAND
11660 109648 70382 0 3 0x80 nanosleep syz-executor.0
11660 182259 70382 0 3 0x4000080 kqread syz-executor.0
11660 424799 70382 0 3 0x4000080 fsleep syz-executor.0
63351 518848 8253 0 3 0x80 nanosleep syz-executor.1
63351 133185 8253 0 3 0x4000080 kqread syz-executor.1
63351 67535 8253 0 3 0x4000080 fsleep syz-executor.1
70382 55324 50410 0 2 0x482 syz-executor.0
42789 370213 0 0 3 0x14200 bored sosplice
48895 97822 0 0 3 0x14200 acct acct
8253 332479 50410 0 2 0x482 syz-executor.1
50410 465060 1269 0 3 0x82 thrsleep syz-fuzzer
50410 379049 1269 0 3 0x4000082 thrsleep syz-fuzzer
50410 102487 1269 0 3 0x4000082 thrsleep syz-fuzzer
50410 476571 1269 0 3 0x4000082 thrsleep syz-fuzzer
50410 449427 1269 0 3 0x4000082 thrsleep syz-fuzzer
50410 30383 1269 0 3 0x4000082 thrsleep syz-fuzzer
50410 57444 1269 0 3 0x4000082 thrsleep syz-fuzzer
50410 247339 1269 0 3 0x4000082 kqread syz-fuzzer
1269 59558 6556 0 3 0x10008a pause ksh
6556 380657 37127 0 3 0x92 select sshd
25256 43877 1 0 3 0x100083 ttyin getty
37127 334509 1 0 3 0x80 select sshd
54692 134679 43713 73 3 0x100090 kqread syslogd
43713 85791 1 0 3 0x100082 netio syslogd
48324 1854 1 77 3 0x100090 poll dhclient
44647 137794 1 0 3 0x80 poll dhclient
27160 336893 0 0 3 0x14200 pgzero zerothread
71950 165696 0 0 3 0x14200 aiodoned aiodoned
94197 455472 0 0 3 0x14200 syncer update
33511 111458 0 0 3 0x14200 cleaner cleaner
71803 490876 0 0 3 0x14200 reaper reaper
38091 123799 0 0 3 0x14200 pgdaemon pagedaemon
54500 384253 0 0 3 0x14200 bored crynlk
94414 500552 0 0 3 0x14200 bored crypto
56534 384275 0 0 3 0x40014200 acpi0 acpi0
68585 58414 0 0 3 0x14200 bored softnet
*12217 240192 0 0 7 0x14200 systqmp
89552 53416 0 0 3 0x14200 bored systq
84140 220726 0 0 3 0x40014200 bored softclock
47092 375037 0 0 3 0x40014200 idle0
30566 334174 0 0 3 0x14200 bored smr
1 126085 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 9516 6349K 7694K 78643K 12457 0
pcb 13 8K 8K 78643K 112 0
rtable 112 3K 4K 78643K 330 0
ifaddr 85 16K 16K 78643K 153 0
counters 19 16K 16K 78643K 19 0
ioctlops 0 0K 2K 78643K 39 0
iov 0 0K 16K 78643K 86 0
mount 1 1K 1K 78643K 1 0
vnodes 1233 77K 78K 78643K 1750 0
UFS quota 1 32K 32K 78643K 1 0
UFS mount 5 36K 36K 78643K 5 0
shm 2 1K 5K 78643K 5 0
VM map 2 0K 0K 78643K 2 0
sem 12 0K 1K 78643K 174 0
dirhash 12 2K 2K 78643K 12 0
ACPI 1794 195K 288K 78643K 12646 0
file desc 6 17K 25K 78643K 388 0
proc 49 38K 63K 78643K 423 0
subproc 32 2K 2K 78643K 51 0
NFS srvsock 1 0K 0K 78643K 1 0
NFS daemon 1 16K 16K 78643K 1 0
ip_moptions 0 0K 0K 78643K 31 0
in_multi 85 4K 4K 78643K 106 0
ether_multi 1 0K 0K 78643K 2 0
mrt 0 0K 0K 78643K 3 0
ISOFS mount 1 32K 32K 78643K 1 0
MSDOSFS mount 1 16K 16K 78643K 1 0
ttys 42 185K 185K 78643K 42 0
exec 0 0K 1K 78643K 241 0
pagedep 1 8K 8K 78643K 1 0
inodedep 1 32K 32K 78643K 1 0
newblk 1 0K 0K 78643K 1 0
VM swap 7 26K 26K 78643K 7 0
UVM amap 130 103K 104K 78643K 2066 0
UVM aobj 29 3K 3K 78643K 33 0
memdesc 1 4K 4K 78643K 1 0
crypto data 1 1K 1K 78643K 1 0
ip6_options 0 0K 0K 78643K 76 0
NDP 14 0K 0K 78643K 29 0
temp 142 3019K 3086K 78643K 5470 0
SYN cache 2 16K 16K 78643K 2 0
ddb> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg
Idle
arp 64 10 0 3 1 0 1 1 0
8 0
rtpcb 80 27 0 25 1 0 1 1 0
8 0
rtentry 112 61 0 15 2 0 2 2 0
8 0
unpcb 120 285 0 277 1 0 1 1 0
8 0
syncache 264 8 0 8 3 3 0 1 0
8 0
tcpqe 32 370 0 370 1 1 0 1 0
8 0
tcpcb 544 264 0 260 4 2 2 2 0
8 1
ipq 40 11 0 11 4 4 0 1 0
8 0
ipqe 40 239 0 239 4 4 0 1 0
8 0
inpcb 280 644 0 637 5 3 2 4 0
8 1
rttmr 72 1 0 1 1 0 1 1 0
8 1
nd6 48 6 0 2 1 0 1 1 0
8 0
pkpcb 40 2 0 2 1 0 1 1 0
8 1
ppxss 1128 8 0 8 4 4 0 1 0
8 0
art_heap8 4096 2 0 0 2 0 2 2 0
8 0
art_heap4 256 277 0 45 16 1 15 15 0
8 0
art_table 32 279 0 45 2 0 2 2 0
8 0
art_node 16 60 0 18 1 0 1 1 0
8 0
sysvmsgpl 40 35 0 26 1 0 1 1 0
8 0
semupl 112 2 0 2 1 1 0 1 0
8 0
semapl 112 172 0 162 1 0 1 1 0
8 0
shmpl 112 31 0 4 1 0 1 1 0
8 0
dirhash 1024 17 0 0 3 0 3 3 0
8 0
dino1pl 128 1964 0 563 46 0 46 46 0
8 0
ffsino 240 1964 0 563 83 0 83 83 0
8 0
nchpl 144 2842 0 1235 61 0 61 61 0
8 0
uvmvnodes 72 2465 0 0 45 0 45 45 0
8 0
vnodes 208 2465 0 0 130 0 130 130 0
8 0
namei 1024 8047 0 8047 2 1 1 1 0
8 1
vcpupl 1984 10 0 0 2 0 2 2 0
8 0
vmpool 528 10 0 0 1 0 1 1 0
8 0
scsiplug 64 1 0 1 1 1 0 1 0
8 0
scxspl 192 7912 0 7912 12 11 1 7 0
8 1
plimitpl 152 50 0 43 1 0 1 1 0
8 0
sigapl 432 556 0 542 2 0 2 2 0
8 0
futexpl 56 12301 0 12299 1 0 1 1 0
8 0
knotepl 112 116 0 97 1 0 1 1 0
8 0
kqueuepl 104 338 0 334 1 0 1 1 0
8 0
pipepl 128 350 0 331 4 3 1 2 0
8 0
fdescpl 424 557 0 542 2 0 2 2 0
8 0
filepl 120 4654 0 4554 5 1 4 5 0
8 0
lockfpl 104 143 0 142 1 0 1 1 0
8 0
lockfspl 48 44 0 43 1 0 1 1 0
8 0
sessionpl 112 18 0 8 1 0 1 1 0
8 0
pgrppl 48 22 0 12 1 0 1 1 0
8 0
ucredpl 96 432 0 425 1 0 1 1 0
8 0
zombiepl 144 542 0 542 2 1 1 1 0
8 1
processpl 864 573 0 542 4 0 4 4 0
8 0
procpl 632 1273 0 1231 6 2 4 5 0
8 0
sosppl 128 14 0 14 3 3 0 1 0
8 0
sockpl 384 967 0 950 9 4 5 6 0
8 3
mcl64k 65536 30 0 29 2 1 1 1 0
8 0
mcl16k 16384 7 0 7 3 3 0 1 0
8 0
mcl12k 12288 10 0 10 3 3 0 1 0
8 0
mcl9k 9216 8 0 7 3 2 1 1 0
8 0
mcl8k 8192 21 0 21 3 2 1 1 0
8 1
mcl4k 4096 58 0 58 2 1 1 1 0
8 1
mcl2k2 2112 2 0 2 2 2 0 1 0
8 0
mcl2k 2048 70388 0 70322 28 19 9 23 0
8 0
mtagpl 80 24 0 2 2 1 1 1 0
8 0
mbufpl 256 115682 0 115528 39 27 12 23 0
8 0
bufpl 280 7241 0 2347 350 0 350 350 0
8 0
anonpl 16 79995 0 63055 119 20 99 99 0 62
16
amapchunkpl 152 3891 0 3746 30 22 8 20 0
158 2
amappl16 192 3227 0 2099 79 13 66 69 0
8 8
amappl15 184 53 0 49 1 0 1 1 0
8 0
amappl14 176 203 0 199 1 0 1 1 0
8 0
amappl12 160 163 0 161 2 1 1 1 0
8 0
amappl11 152 53 0 41 1 0 1 1 0
8 0
amappl10 144 26 0 22 1 0 1 1 0
8 0
amappl9 136 577 0 574 1 0 1 1 0
8 0
amappl8 128 129 0 101 1 0 1 1 0
8 0
amappl7 120 111 0 99 1 0 1 1 0
8 0
amappl6 112 53 0 48 1 0 1 1 0
8 0
amappl5 104 292 0 282 1 0 1 1 0
8 0
amappl4 96 460 0 432 1 0 1 1 0
8 0
amappl3 88 624 0 610 1 0 1 1 0
8 0
amappl2 80 3612 0 3533 3 1 2 3 0
8 0
amappl1 72 20318 0 19873 26 16 10 20 0
8 0
amappl 80 1538 0 1485 2 0 2 2 0
84 0
dma4096 4096 1 0 1 1 1 0 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 64 32 0 4 1 0 1 1 0
8 0
uaddrrnd 24 567 0 542 1 0 1 1 0
8 0
uaddrbest 32 2 0 0 1 0 1 1 0
8 0
uaddr 24 567 0 542 1 0 1 1 0
8 0
vmmpekpl 168 8395 0 8369 2 0 2 2 0
8 0
vmmpepl 168 76285 0 73913 184 42 142 142 0 357
38
vmsppl 272 566 0 542 2 0 2 2 0
8 0
pdppl 4096 1140 0 1094 6 0 6 6 0
8 0
pvpl 32 224633 0 204408 251 24 227 227 0 265
37
pmappl 200 566 0 542 2 0 2 2 0
8 0
extentpl 40 46 0 29 1 0 1 1 0
8 0
phpool 112 197 0 58 5 0 5 5 0
8 0


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This bug is generated by a bot. It may contain errors.
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Anton Lindqvist

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Dec 9, 2019, 4:34:35 AM12/9/19
to syzbot, syzkaller-o...@googlegroups.com
#syz dup: pool: free list modified: mbufpl
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