3kernel: pa e
aStopped at savectx+0xae: movl $0,%gs:0x688
TID PID UID PRFLAGS PFLAGS CPU COMMAND
* 21482 34701 0 0x10 0 1 syz-executor
185009 34701 0 0x10 0x4000000 0K syz-executor
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72656b02dc00, 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{1}>
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu0: uvm_fault(0xfffffd806c7269a8, 0x98, 0, 1) -> e
ddb{1}> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72656b02dc00, count: -1
ddb{1}> show registers
rdi 0
rsi 0
rbp 0xffff80003c41b260
rbx 0
rdx 0
rcx 0xffff8000357b9a18
rax 0x39
r8 0xffff80003c41b190
r9 0x1
r10 0xca42531e5d4fc90a
r11 0x65824098b5e86597
r12 0
r13 0
r14 0xffff8000357b9a18
r15 0
rip 0xffffffff81fad3ee savectx+0xae
cs 0x8
rflags 0x46
rsp 0xffff80003c41b1e0
ss 0x10
savectx+0xae: movl $0,%gs:0x688
ddb{1}> show proc
PROC (syz-executor) tid=21482 pid=34701 tcnt=4 stat=onproc
flags process=10<SUGID> proc=0
runpri=50, usrpri=50, slppri=36, nice=20
wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
forw=0xffffffffffffffff, list=0xffff8000357b9780,0xffff8000357b9cc0
process=0xffff80003c3f7510 user=0xffff80003c416000, vmspace=0xfffffd806c7269a8
estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
*34701 21482 87933 0 7 0x10 syz-executor
34701 185009 87933 0 7 0x4000010 syz-executor
34701 387188 87933 0 2 0x4000010 syz-executor
34701 98465 87933 0 2 0x4000010 syz-executor
16772 30231 72184 0 2 0x2 sshd-auth
99558 128373 26738 0 2 0 syz-executor
99558 415078 26738 0 3 0x4000080 fsleep syz-executor
99558 263358 26738 0 3 0x4000080 fsleep syz-executor
99558 290864 26738 0 3 0x4000080 fsleep syz-executor
8336 364440 10808 0 2 0 syz-executor
8336 502877 10808 0 3 0x4000080 fsleep syz-executor
72184 122229 545 0 3 0x82 kqread sshd-session
22431 1037 88300 0 2 0 syz-executor
22431 474429 88300 0 3 0x4000080 fsleep syz-executor
33887 480795 98949 0 2 0 syz-executor
33887 386934 98949 0 2 0x4000000 syz-executor
33887 43130 98949 0 3 0x4000000 inode syz-executor
33887 109149 98949 0 2 0x4000000 syz-executor
22684 262590 46664 0 3 0x80 nanoslp syz-executor
22684 523917 46664 0 3 0x4000080 msgwait syz-executor
22684 33448 46664 0 3 0x4000088 kqpoll syz-executor
22684 217423 46664 0 3 0x4000080 fsleep syz-executor
99976 67242 55464 0 2 0 syz-executor
99976 190661 55464 0 3 0x4000080 kqread syz-executor
99976 215622 55464 0 3 0x4000080 fsleep syz-executor
74910 217302 6631 0 2 0 syz-executor
74910 196146 6631 0 3 0x4000088 kqread syz-executor
74910 42317 6631 0 3 0x4000080 fsleep syz-executor
10808 232328 98235 0 3 0x82 nanoslp syz-executor
55464 178069 98235 0 3 0x82 nanoslp syz-executor
98949 50080 98235 0 3 0x82 nanoslp syz-executor
46664 340836 98235 0 2 0x2 syz-executor
88300 49001 98235 0 3 0x82 nanoslp syz-executor
6631 423495 98235 0 3 0x82 nanoslp syz-executor
26738 410468 98235 0 3 0x82 nanoslp syz-executor
87933 426888 98235 0 3 0x82 nanoslp syz-executor
98235 67955 86973 0 3 0x82 kqread syz-executor
86973 406951 54875 0 3 0x10008a sigsusp ksh
54875 111343 64090 0 3 0x98 kqread sshd-session
64090 496526 545 0 3 0x92 kqread sshd-session
66301 47600 1 0 3 0x100083 ttyopn getty
545 415504 1 0 3 0x88 kqread sshd
89562 208732 27590 74 3 0x1100092 bpf pflogd
27590 21637 1 0 3 0x80 sbwait pflogd
1527 440566 11442 73 3 0x1100090 kqread syslogd
11442 429938 1 0 3 0x100082 sbwait syslogd
51113 464026 1 0 3 0x100080 kqread resolvd
20832 133382 15192 77 3 0x100092 kqread dhcpleased
86458 379243 15192 77 3 0x100092 kqread dhcpleased
15192 181773 1 0 3 0x80 kqread dhcpleased
81120 380676 0 0 3 0x14200 bored smr
50509 24807 0 0 2 0x14200 zerothread
33173 507180 0 0 3 0x14200 aiodoned aiodoned
28020 321868 0 0 3 0x14200 syncer update
48539 301841 0 0 3 0x14200 cleaner cleaner
67937 58270 0 0 3 0x14200 reaper reaper
87489 15243 0 0 3 0x14200 pgdaemon pagedaemon
96792 58579 0 0 3 0x14200 bored viomb
73702 371281 0 0 3 0x40014200 acpi0 acpi0
78607 318559 0 0 3 0x40014200 idle1
14639 373586 0 0 3 0x14200 bored softnet1
28269 34079 0 0 3 0x14200 bored softnet0
87255 356298 0 0 3 0x14200 bored systqmp
76306 183663 0 0 3 0x14200 bored systq
19480 110813 0 0 3 0x14200 tmoslp softclockmp
39440 43376 0 0 3 0x40014200 tmoslp softclock
44776 283528 0 0 3 0x40014200 idle0
1 136574 0 0 3 0x80082 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
CPU 1:
exclusive mutex &sched_lock r = 0 (0xffffffff839d51d0)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 mtx_enter+0x4b4 sys/kern/kern_lock.c:487
#2 sleep_finish+0x1d6 sys/kern/kern_synch.c:357
#3 biowait+0xc6 sys/kern/vfs_bio.c:1242
#4 bwrite+0x2e7 sys/kern/vfs_bio.c:754
#5 ffs2_balloc+0x18b4 sys/ufs/ffs/ffs_balloc.c:701
#6 ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
#7 VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
#8 vn_write+0x1d3 sys/kern/vfs_vnops.c:408
#9 dofilewritev+0x2bd sys/kern/sys_generic.c:384
#10 sys_write+0xa2 sys/kern/sys_generic.c:300
#11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#12 Xsyscall+0x128
Process 34701 (syz-executor) thread 0xffff8000357b9cb0 (185009)
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a89600)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
#1 syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783
#2 Xsyscall+0x128
Process 33887 (syz-executor) thread 0xffff8000357b94e8 (386934)
exclusive rrwlock inode r = 0 (0xfffffd80651d4c58)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570
#5 vn_write+0x18f sys/kern/vfs_vnops.c:405
#6 dofilewritev+0x2bd sys/kern/sys_generic.c:384
#7 sys_write+0xa2 sys/kern/sys_generic.c:300
#8 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#9 Xsyscall+0x128
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 11067 12147K 12281K 166960K 12205 0
pcb 18 12K 12K 166960K 31 0
rtable 227 7K 8K 166960K 379 0
pf 36 18K 20K 166960K 54 0
ifaddr 43 7K 7K 166960K 47 0
ifgroup 55 2K 2K 166960K 57 0
sysctl 3 1K 9K 166960K 8 0
counters 70 37K 37K 166960K 76 0
ioctlops 0 0K 4K 166960K 1502 0
iov 0 0K 0K 166960K 1 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1294 81K 82K 166960K 1403 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 5 0
VM map 2 1K 1K 166960K 2 0
sem 4 0K 0K 166960K 4 0
dirhash 12 2K 2K 166960K 12 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 18 65K 89K 166960K 195 0
proc 71 115K 164K 166960K 556 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 0 0K 0K 166960K 5 0
in_multi 99 7K 7K 166960K 103 0
ether_multi 1 0K 0K 166960K 1 0
mrt 0 0K 0K 166960K 3 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 61 281K 281K 166960K 61 0
exec 0 0K 1K 166960K 390 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 263 169K 173K 166960K 3691 0
UVM aobj 8 2K 2K 166960K 8 0
pinsyscall 47 94K 104K 166960K 1362 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 12 0K 2K 166960K 29 0
temp 37 9074K 9138K 166960K 4390 0
kqueue 16 26K 28K 166960K 34 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 40 0 37 1 0 1 1 0 8 0
rtentry 176 112 0 12 6 0 6 6 0 8 0
unpcb 144 68 0 44 2 0 2 2 0 8 0
syncache 336 4 0 4 1 0 1 1 0 8 1
tcpcb 736 21 0 15 1 0 1 1 0 8 0
arp 136 18 0 0 1 0 1 1 0 8 0
inpcb 328 102 0 92 2 0 2 2 0 8 1
nd6 152 24 0 0 1 0 1 1 0 8 0
pkpcb 40 2 0 2 1 0 1 1 0 8 1
kcovpl 48 8 0 0 1 0 1 1 0 8 0
ppxss 1192 3 0 3 1 0 1 1 0 8 1
pfstscr 40 1 0 1 1 0 1 1 0 8 1
pfosfp 40 1428 0 1005 5 0 5 5 0 8 0
pfosfpen 112 1428 0 714 21 0 21 21 0 8 0
pftag 88 1 0 0 1 0 1 1 0 8 0
pfqueue 320 1 0 1 1 0 1 1 0 8 1
pfstitem 24 22 0 0 1 0 1 1 0 8 0
pfstkey 128 24 0 2 1 0 1 1 0 8 0
pfstate 448 23 0 1 3 0 3 3 0 8 0
pfrule 1360 24 0 18 2 1 1 2 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 483 0 41 31 0 31 31 0 8 1
art_table 40 484 0 41 5 0 5 5 0 8 0
art_node 32 112 0 22 1 0 1 1 0 8 0
semapl 112 2 0 0 1 0 1 1 0 8 0
shmpl 112 5 0 0 1 0 1 1 0 8 0
dirhash 1024 17 0 0 3 0 3 3 0 8 0
dino2pl 256 1663 0 196 93 0 93 93 0 8 1
ffsino 296 1663 0 196 114 0 114 114 0 8 0
nchpl 144 1936 0 237 64 0 64 64 0 8 0
vnodes 216 1777 0 0 99 0 99 99 0 8 0
namei 1024 6096 0 6096 2 0 2 2 0 8 2
percpumem 16 53 0 3 1 0 1 1 0 8 0
kstatmem 264 28 0 2 2 0 2 2 0 8 0
scxspl 216 7133 0 7133 4 2 2 3 1 8 2
plimitpl 152 37 0 17 1 0 1 1 0 8 0
sigapl 424 515 0 465 7 0 7 7 0 8 1
knotepl 120 281 0 0 9 0 9 9 0 8 0
kqueuepl 224 40 0 25 2 0 2 2 0 8 0
pipepl 344 128 0 98 3 0 3 3 0 8 0
fdescpl 528 499 0 465 3 0 3 3 0 8 0
filepl 160 1859 0 1620 11 0 11 11 0 8 1
lockfpl 104 32 0 27 1 0 1 1 0 8 0
lockfspl 48 16 0 11 1 0 1 1 0 8 0
sessionpl 144 24 0 14 1 0 1 1 0 8 0
pgrppl 48 32 0 14 1 0 1 1 0 8 0
ucredpl 104 144 0 128 1 0 1 1 0 8 0
zombiepl 144 465 0 465 1 0 1 1 0 8 1
processpl 1232 515 0 465 5 0 5 5 0 8 0
procpl 664 627 0 559 6 0 6 6 0 8 0
sockpl 752 213 0 175 5 0 5 5 0 8 1
mcl64k 65536 6 0 0 1 0 1 1 0 8 0
mcl16k 16384 6 0 0 1 0 1 1 0 8 0
mcl12k 12288 2 0 0 1 0 1 1 0 8 0
mcl8k 8192 3 0 0 1 0 1 1 0 8 0
mcl4k 4096 133 0 0 17 0 17 17 0 8 0
mcl2k 2048 18 0 0 3 0 3 3 0 8 0
mtagpl 96 2 0 0 1 0 1 1 0 8 0
mbufpl 256 153 0 0 10 0 10 10 0 8 0
bufpl 280 2769 0 105 191 0 191 191 0 8 0
anonpl 32 6314 0 0 51 0 51 51 0 246 0
amapchunkpl 152 10901 0 10225 28 0 28 28 0 158 2
amappl16 200 2059 0 2007 5 0 5 5 0 8 2
amappl15 192 7 0 6 2 1 1 1 0 8 0
amappl14 184 434 0 433 1 0 1 1 0 8 0
amappl13 176 138 0 125 1 0 1 1 0 8 0
amappl12 168 749 0 717 2 0 2 2 0 8 0
amappl11 160 4 0 4 1 1 0 1 0 8 0
amappl10 152 69 0 55 1 0 1 1 0 8 0
amappl9 144 272 0 272 1 0 1 1 0 8 1
amappl8 136 106 0 104 1 0 1 1 0 8 0
amappl7 128 160 0 145 1 0 1 1 0 8 0
amappl6 120 158 0 156 1 0 1 1 0 8 0
amappl5 112 97 0 84 1 0 1 1 0 8 0
amappl4 104 316 0 296 1 0 1 1 0 8 0
amappl3 96 1873 0 1745 4 0 4 4 0 8 0
amappl2 88 545 0 472 2 0 2 2 0 8 0
amappl1 80 10068 0 9335 15 0 15 15 0 8 0
amappl 88 2945 0 2761 5 0 5 5 0 92 0
uvmvnodes 80 100 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 7 0 0 1 0 1 1 0 8 0
uaddrrnd 24 499 0 465 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 499 0 465 1 0 1 1 0 8 0
vmmpekpl 168 5967 0 5932 2 0 2 2 0 8 0
vmmpepl 168 40863 0 38640 99 0 99 99 0 357 2
vmsppl 488 498 0 465 5 0 5 5 0 8 0
rwobjpl 80 14920 0 13686 26 0 26 26 0 8 0
pdppl 4096 1005 0 930 101 26 75 83 0 8 0
pvpl 32 13846 0 0 112 0 112 112 0 265 0
pmappl 256 498 0 465 3 0 3 3 0 8 0
extentpl 40 45 0 27 1 0 1 1 0 8 0
phpool 112 277 0 29 8 0 8 8 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
x86_ipi_db(ffffffff8386fff0) 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
x86_bus_space_io_write_1(3f8,0,61) at x86_bus_space_io_write_1+0x40 sys/arch/amd64/amd64/bus_space.c:790
comcnputc(800,61) at comcnputc+0x1ab bus_space_barrier sys/dev/ic/com.c:-1 [inline]
comcnputc(800,61) at comcnputc+0x1ab sys/dev/ic/com.c:1278
cnputc(61) at cnputc+0x67 sys/dev/cons.c:218
db_putchar(61) at db_putchar+0x36d sys/ddb/db_output.c:155
kprintf() at kprintf+0x29c5 sys/kern/subr_prf.c:-1
db_printf(ffffffff83440706) at db_printf+0x9b sys/kern/subr_prf.c:-1
db_ktrap(6,0,ffff80003c44cd40) at db_ktrap+0x1b6 db_printtrap sys/arch/amd64/amd64/db_interface.c:103 [inline]
db_ktrap(6,0,ffff80003c44cd40) at db_ktrap+0x1b6 sys/arch/amd64/amd64/db_interface.c:128
kerntrap(ffff80003c44cd40) at kerntrap+0x243 sys/arch/amd64/amd64/trap.c:519
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
dovutimens(ffff8000357b9cb0,fffffd806555b8a8,ffff80003c44cf20) at dovutimens+0x368 sys/kern/vfs_syscalls.c:2771
sys_futimes(ffff8000357b9cb0,ffff80003c44d070,ffff80003c44cfc0) at sys_futimes+0x208 sys/kern/vfs_syscalls.c:2813
end trace frame: 0xffff80003c44d060, count: 0
ddb{0}> trace
x86_ipi_db(ffffffff8386fff0) 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
x86_bus_space_io_write_1(3f8,0,61) at x86_bus_space_io_write_1+0x40 sys/arch/amd64/amd64/bus_space.c:790
comcnputc(800,61) at comcnputc+0x1ab bus_space_barrier sys/dev/ic/com.c:-1 [inline]
comcnputc(800,61) at comcnputc+0x1ab sys/dev/ic/com.c:1278
cnputc(61) at cnputc+0x67 sys/dev/cons.c:218
db_putchar(61) at db_putchar+0x36d sys/ddb/db_output.c:155
kprintf() at kprintf+0x29c5 sys/kern/subr_prf.c:-1
db_printf(ffffffff83440706) at db_printf+0x9b sys/kern/subr_prf.c:-1
db_ktrap(6,0,ffff80003c44cd40) at db_ktrap+0x1b6 db_printtrap sys/arch/amd64/amd64/db_interface.c:103 [inline]
db_ktrap(6,0,ffff80003c44cd40) at db_ktrap+0x1b6 sys/arch/amd64/amd64/db_interface.c:128
kerntrap(ffff80003c44cd40) at kerntrap+0x243 sys/arch/amd64/amd64/trap.c:519
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
dovutimens(ffff8000357b9cb0,fffffd806555b8a8,ffff80003c44cf20) at dovutimens+0x368 sys/kern/vfs_syscalls.c:2771
sys_futimes(ffff8000357b9cb0,ffff80003c44d070,ffff80003c44cfc0) at sys_futimes+0x208 sys/kern/vfs_syscalls.c:2813
syscall(ffff80003c44d070) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c44d070) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x56424c31e20, count: -16
ddb{0}> machine ddbcpu 1
Stopped at savectx+0xae: movl $0,%gs:0x688
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72656b02dc00, count: 14
ddb{1}> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x72656b02dc00, count: -1