uvm_fault: m_free (2)

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syzbot

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Nov 18, 2019, 10:23:08 PM11/18/19
to syzkaller-o...@googlegroups.com
Hello,

syzbot found the following crash on:

HEAD commit: d2a7ef38 additional missing stdarg.h includes when built w..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=13cb9836e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d0fe83f82fe104d4
dashboard link: https://syzkaller.appspot.com/bug?extid=67b070c37a1bc570e69a

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+67b070...@syzkaller.appspotmail.com

uvm_fault(0xffffffff82562890, 0xfffffd000000001c, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at m_free+0x3b: movswq 0x1c(%r14),%rdx
ddb>
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
kernel page fault
uvm_fault(0xffffffff82562890, 0xfffffd000000001c, 0, 1) -> e
m_free(fffffd0000000000) at m_free+0x3b sys/kern/uipc_mbuf.c:435
end trace frame: 0xffff800014924030, count: 0
ddb> trace
m_free(fffffd0000000000) at m_free+0x3b sys/kern/uipc_mbuf.c:435
ml_purge(ffff800014924048) at ml_purge+0x50 m_freem
sys/kern/uipc_mbuf.c:538 [inline]
ml_purge(ffff800014924048) at ml_purge+0x50 sys/kern/uipc_mbuf.c:1628
ifq_purge(ffff800000a65a78) at ifq_purge+0x97 sys/net/ifq.c:423
tapclose(5d00,7,2000,ffff8000ffff29f8) at tapclose+0xed tun_dev_close
sys/net/if_tun.c:417 [inline]
tapclose(5d00,7,2000,ffff8000ffff29f8) at tapclose+0xed sys/net/if_tun.c:396
spec_close(ffff800014924160) at spec_close+0x311 sys/kern/spec_vnops.c:555
VOP_CLOSE(fffffd8037bf18f0,7,fffffd803f7c6720,ffff8000ffff29f8) at
VOP_CLOSE+0xc0 sys/kern/vfs_vops.c:175
vn_closefile(fffffd8037560258,ffff8000ffff29f8) at vn_closefile+0xd3
vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffffd8037560258,ffff8000ffff29f8) at vn_closefile+0xd3
sys/kern/vfs_vnops.c:610
fdrop(fffffd8037560258,ffff8000ffff29f8) at fdrop+0xc2
sys/kern/kern_descrip.c:1273
closef(fffffd8037560258,ffff8000ffff29f8) at closef+0x118
sys/kern/kern_descrip.c:1257
fdfree(ffff8000ffff29f8) at fdfree+0x100 sys/kern/kern_descrip.c:1189
exit1(ffff8000ffff29f8,9,1) at exit1+0x32f sys/kern/kern_exit.c:196
postsig(ffff8000ffff29f8,9) at postsig+0x4a6 sigexit
sys/kern/kern_sig.c:1499 [inline]
postsig(ffff8000ffff29f8,9) at postsig+0x4a6 sys/kern/kern_sig.c:1431
userret(ffff8000ffff29f8) at userret+0x159 sys/kern/kern_sig.c:1889
syscall(ffff8000149245e0) at syscall+0x42e mi_syscall_return
sys/sys/syscall_mi.h:115 [inline]
syscall(ffff8000149245e0) at syscall+0x42e sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffdaff0, count: -15
ddb> show registers
rdi 0
rsi 0x7
rbp 0xffff800014923ff0
rbx 0
rdx 0xffffffff8258a6b0 mbpool+0x38
rcx 0xffffffff82559c60 mbstat_boot_boot_cpumem
rax 0
r8 0
r9 0x5
r10 0x31c1ed8ad337db81
r11 0xf789d6298a1696bf
r12 0xfffffd802e31a900
r13 0x2000 __ALIGN_SIZE+0x1000
r14 0xfffffd0000000000
r15 0xfffffd0000000000
rip 0xffffffff8194412b m_free+0x3b
cs 0x8
rflags 0x10246 __ALIGN_SIZE+0xf246
rsp 0xffff800014923fb0
ss 0x10
m_free+0x3b: movswq 0x1c(%r14),%rdx
ddb> show proc
PROC (syz-executor.0) pid=236447 stat=onproc
flags process=a<EXEC,EXITING> proc=2000<WEXIT>
pri=32, usrpri=50, nice=20
forw=0xffffffffffffffff, list=0xffff8000ffff3b40,0xffff8000ffff33e8
process=0xffff8000148a3b18 user=0xffff80001491f000,
vmspace=0xfffffd803f011550
estcpu=0, cpticks=1, pctcpu=0.0
user=0, sys=1, intr=0
ddb> ps
PID TID PPID UID S FLAGS WAIT COMMAND
6571 252509 8214 0 3 0x82 wait syz-executor.1
71837 5791 1 0 3 0x100083 ttyin getty
37179 21222 0 0 3 0x14200 bored sosplice
8214 73340 99884 0 3 0x82 thrsleep syz-fuzzer
8214 293933 99884 0 2 0x4000002 syz-fuzzer
8214 358738 99884 0 3 0x4000082 thrsleep syz-fuzzer
8214 387763 99884 0 3 0x4000082 thrsleep syz-fuzzer
8214 85548 99884 0 2 0x4000002 syz-fuzzer
8214 273517 99884 0 2 0x4000082 syz-fuzzer
8214 224995 99884 0 3 0x4000082 thrsleep syz-fuzzer
8214 15953 99884 0 2 0x4000002 syz-fuzzer
99884 247118 19277 0 3 0x10008a pause ksh
19277 152444 80345 0 3 0x92 select sshd
80345 462681 1 0 3 0x80 select sshd
43863 77257 81955 73 2 0x100010 syslogd
81955 127469 1 0 3 0x100082 netio syslogd
88921 298470 0 0 2 0x14200 zerothread
17671 509126 0 0 3 0x14200 aiodoned aiodoned
20668 263988 0 0 3 0x14200 syncer update
17775 83658 0 0 3 0x14200 cleaner cleaner
82183 575 0 0 2 0x14200 reaper
66431 457809 0 0 3 0x14200 pgdaemon pagedaemon
23866 523263 0 0 3 0x14200 bored crynlk
21029 207234 0 0 3 0x14200 bored crypto
22314 81139 0 0 3 0x40014200 acpi0 acpi0
92740 361360 0 0 2 0x14200 softnet
55896 479475 0 0 3 0x14200 bored systqmp
21635 352875 0 0 3 0x14200 bored systq
69372 193830 0 0 3 0x40014200 bored softclock
15709 189355 0 0 3 0x40014200 idle0
12085 80438 0 0 3 0x14200 bored smr
1 170179 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 Kern Lim
devbuf 9550 6311K 8175K 78643K 20779 0 0
pcb 13 9K 9K 78643K 1065 0 0
rtable 104 4K 5K 78643K 903 0 0
ifaddr 108 20K 21K 78643K 480 0 0
counters 19 16K 16K 78643K 19 0 0
ioctlops 0 0K 2K 78643K 106 0 0
iov 0 0K 28K 78643K 392 0 0
mount 1 1K 1K 78643K 1 0 0
vnodes 1240 78K 78K 78643K 4133 0 0
UFS quota 1 32K 32K 78643K 1 0 0
UFS mount 5 36K 36K 78643K 5 0 0
shm 2 1K 5K 78643K 40 0 0
VM map 24 6K 6K 78643K 30 0 0
sem 12 1K 1K 78643K 121 0 0
dirhash 12 2K 2K 78643K 12 0 0
ACPI 1794 195K 288K 78643K 12646 0 0
file desc 4 9K 25K 78643K 1881 0 0
sigio 0 0K 0K 78643K 30 0 0
proc 44 30K 63K 78643K 720 0 0
subproc 23 1K 2K 78643K 140 0 0
NFS srvsock 1 0K 0K 78643K 1 0 0
NFS daemon 1 16K 16K 78643K 1 0 0
ip_moptions 0 0K 0K 78643K 258 0 0
in_multi 82 4K 4K 78643K 273 0 0
ether_multi 1 0K 0K 78643K 17 0 0
mrt 0 0K 0K 78643K 10 0 0
ISOFS mount 1 32K 32K 78643K 1 0 0
MSDOSFS mount 1 16K 16K 78643K 1 0 0
ttys 84 371K 371K 78643K 84 0 0
exec 0 0K 1K 78643K 456 0 0
pfkey data 0 0K 0K 78643K 8 0 0
pagedep 1 8K 8K 78643K 1 0 0
inodedep 1 32K 32K 78643K 1 0 0
newblk 1 0K 0K 78643K 1 0 0
VM swap 7 26K 26K 78643K 7 0 0
UVM amap 144 188K 190K 78643K 5424 0 0
UVM aobj 130 8K 8K 78643K 138 0 0
memdesc 1 4K 4K 78643K 1 0 0
crypto data 1 1K 1K 78643K 1 0 0
ip6_options 0 0K 0K 78643K 836 0 0
NDP 19 0K 0K 78643K 114 0 0
temp 162 3539K 3611K 78643K 35369 0 0
kqueue 0 0K 0K 78643K 24 0 0
SYN cache 2 16K 16K 78643K 2 0 0
ddb> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg
Idle
arp 64 29 0 21 1 0 1 1 0
8 0
rtpcb 80 472 0 472 2 2 0 1 0
8 0
rtentry 112 183 0 144 2 0 2 2 0
8 0
unpcb 120 2044 0 2037 3 2 1 2 0
8 0
syncache 264 14 0 14 6 6 0 1 0
8 0
tcpqe 32 80 0 80 3 3 0 1 0
8 0
tcpcb 544 765 0 761 4 2 2 2 0
8 1
ipq 40 24 0 24 6 6 0 1 0
8 0
ipqe 40 703 0 703 6 6 0 1 0
8 0
inpcb 280 2928 0 2924 11 10 1 4 0
8 0
rttmr 72 2 0 2 2 2 0 1 0
8 0
nd6 48 30 0 28 1 0 1 1 0
8 0
pkpcb 40 19 0 19 5 5 0 1 0
8 0
swfcl 56 2 0 0 1 0 1 1 0
8 0
ppxss 1128 44 0 44 10 10 0 1 0
8 0
art_heap8 4096 4 0 2 4 2 2 4 0
8 0
art_heap4 256 1013 0 784 19 3 16 19 0
8 0
art_table 32 1017 0 786 3 0 3 3 0
8 0
art_node 16 182 0 145 1 0 1 1 0
8 0
sysvmsgpl 40 26 0 17 1 0 1 1 0
8 0
semupl 112 1 0 1 1 1 0 1 0
8 0
semapl 112 118 0 108 1 0 1 1 0
8 0
shmpl 112 136 0 8 4 0 4 4 0
8 0
dirhash 1024 17 0 0 3 0 3 3 0
8 0
dino1pl 128 4234 0 2842 46 0 46 46 0
8 0
ffsino 240 4234 0 2842 83 0 83 83 0
8 0
nchpl 144 7635 0 7215 60 40 20 60 0
8 0
uvmvnodes 72 5930 0 0 108 0 108 108 0
8 0
vnodes 208 5930 0 0 313 0 313 313 0
8 0
namei 1024 25059 0 25059 3 3 0 1 0
8 0
vcpupl 1984 22 0 0 3 0 3 3 0
8 0
vmpool 520 28 0 6 2 0 2 2 0
8 0
scsiplug 64 1 0 1 1 1 0 1 0
8 0
scxspl 192 23415 0 23415 17 16 1 7 0
8 1
plimitpl 152 189 0 182 1 0 1 1 0
8 0
sigapl 432 2034 0 2024 2 0 2 2 0
8 0
futexpl 56 62017 0 62017 4 4 0 1 0
8 0
knotepl 112 453 0 434 3 2 1 3 0
8 0
kqueuepl 104 871 0 869 1 0 1 1 0
8 0
pipepl 128 1206 0 1188 9 8 1 2 0
8 0
fdescpl 424 2035 0 2024 2 0 2 2 0
8 0
filepl 120 19597 0 19523 12 9 3 5 0
8 0
lockfpl 104 602 0 602 1 1 0 1 0
8 0
lockfspl 48 200 0 200 1 1 0 1 0
8 0
sessionpl 112 24 0 16 1 0 1 1 0
8 0
pgrppl 48 44 0 36 1 0 1 1 0
8 0
ucredpl 96 1991 0 1983 1 0 1 1 0
8 0
zombiepl 144 2026 0 2023 2 1 1 1 0
8 0
processpl 864 2051 0 2023 4 0 4 4 0
8 0
procpl 632 4337 0 4301 4 0 4 4 0
8 0
sosppl 128 34 0 34 8 8 0 1 0
8 0
sockpl 384 5493 0 5482 26 24 2 7 0
8 0
mcl64k 65536 226 0 226 11 11 0 3 0
8 0
mcl16k 16384 28 0 28 7 7 0 1 0
8 0
mcl12k 12288 72 0 72 6 6 0 1 0
8 0
mcl9k 9216 29 0 29 7 7 0 1 0
8 0
mcl8k 8192 115 0 115 5 5 0 1 0
8 0
mcl4k 4096 221 0 221 4 4 0 1 0
8 0
mcl2k2 2112 22 0 22 4 4 0 1 0
8 0
mcl2k 2048 73148 0 73105 17 10 7 14 0
8 0
mtagpl 80 112 0 64 3 1 2 2 0
8 0
mbufpl 256 134611 0 134376 111 94 17 33 0
8 0
bufpl 256 12285 0 6236 379 0 379 379 0
8 0
anonpl 16 264567 0 238834 159 55 104 104 0
62 0
amapchunkpl 152 9890 0 9447 42 24 18 18 0
158 0
amappl16 192 12563 0 11387 144 85 59 71 0
8 0
amappl15 184 612 0 611 2 1 1 1 0
8 0
amappl14 176 183 0 177 1 0 1 1 0
8 0
amappl13 168 741 0 738 1 0 1 1 0
8 0
amappl12 160 8 0 6 2 1 1 1 0
8 0
amappl11 152 301 0 295 1 0 1 1 0
8 0
amappl10 144 187 0 182 1 0 1 1 0
8 0
amappl9 136 866 0 862 1 0 1 1 0
8 0
amappl8 128 456 0 414 2 0 2 2 0
8 0
amappl7 120 236 0 228 1 0 1 1 0
8 0
amappl6 112 294 0 281 1 0 1 1 0
8 0
amappl5 104 208 0 201 1 0 1 1 0
8 0
amappl4 96 2933 0 2902 1 0 1 1 0
8 0
amappl3 88 376 0 368 1 0 1 1 0
8 0
amappl2 80 15481 0 15412 3 1 2 3 0
8 0
amappl1 72 44912 0 44501 26 16 10 20 0
8 0
amappl 80 4701 0 4645 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 64 137 0 8 3 0 3 3 0
8 0
uaddrrnd 24 2063 0 2023 1 0 1 1 0
8 0
uaddrbest 32 2 0 0 1 0 1 1 0
8 0
uaddr 24 2063 0 2023 1 0 1 1 0
8 0
vmmpekpl 168 16804 0 16774 2 0 2 2 0
8 0
vmmpepl 168 253707 0 251369 237 131 106 145 0
357 0
vmsppl 272 2034 0 2022 2 1 1 2 0
8 0
pdppl 4096 4132 0 4078 8 1 7 7 0
8 0
pvpl 32 688195 0 663940 418 94 324 339 0 265
119
pmappl 200 2062 0 2028 2 0 2 2 0
8 0
extentpl 40 46 0 29 1 0 1 1 0
8 0
phpool 112 662 0 145 15 0 15 15 0
8 0


---
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syzbot

unread,
Sep 23, 2020, 9:01:18 AM9/23/20
to syzkaller-o...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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