panic: kernel diagnostic assertion "uvn->u_obj.uo_refs == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/uvm/uvm_vnode.c", line 234
Stopped at db_enter+0x18: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
377908 39095 32767 0x10 0 0 syz-executor.3
* 32128 39095 32767 0x10 0x4000000 1K syz-executor.3
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a14e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff82617e14,ffffffff82639607,ea,ffffffff826320a6) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a846368,6) at uvn_attach+0x444 sys/uvm/uvm_vnode.c:234
uvm_mmapfile(fffffd8075116468,ffff8000214b75e8,10000,2,6,11,eb3fbe5eda94103,fffffd8075116468,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff800021431a40,ffff8000214b7690,ffff8000214b7760) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff800021431a40,ffff8000214b7718,ffff8000214b7760) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff8000214b77e0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff8000214b77e0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0b6ce60f0, count: 6
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 "uvn->u_obj.uo_refs == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/uvm/uvm_vnode.c", line 234
ddb{1}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a14e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff82617e14,ffffffff82639607,ea,ffffffff826320a6) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a846368,6) at uvn_attach+0x444 sys/uvm/uvm_vnode.c:234
uvm_mmapfile(fffffd8075116468,ffff8000214b75e8,10000,2,6,11,eb3fbe5eda94103,fffffd8075116468,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff800021431a40,ffff8000214b7690,ffff8000214b7760) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff800021431a40,ffff8000214b7718,ffff8000214b7760) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff8000214b77e0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff8000214b77e0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0b6ce60f0, count: -9
ddb{1}> show registers
rdi 0
rsi 0x1
rbp 0xffff8000214b7280
rbx 0xffff800020dd9b8f
rdx 0x3fd
rcx 0
rax 0x8c
r8 0x101010101010101
r9 0x8080808080808080
r10 0x53a6e73c142fc0ad
r11 0x5354521a400ba36
r12 0xffff800020dd9990
r13 0
r14 0
r15 0x1
rip 0xffffffff81a81af8 db_enter+0x18
cs 0x8
rflags 0x246
rsp 0xffff8000214b7270
ss 0x10
db_enter+0x18: addq $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor.3) pid=32128 stat=onproc
flags process=10<SUGID> proc=4000000<THREAD>
pri=32, usrpri=86, nice=20
forw=0xffffffffffffffff, list=0xffff80002144cd30,0xffff800021430010
process=0xffff8000213ee580 user=0xffff8000214b2000, vmspace=0xfffffd8075116468
estcpu=36, cpticks=3, pctcpu=0.0
user=0, sys=2, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
96267 244397 213 32767 2 0x10 syz-executor.1
96267 479036 213 32767 3 0x4000090 fsleep syz-executor.1
39095 377908 73774 32767 7 0x10 syz-executor.3
*39095 32128 73774 32767 7 0x4000010 syz-executor.3
39095 194576 73774 32767 2 0x4000010 syz-executor.3
9254 209200 24248 32767 3 0x90 nanoslp syz-executor.2
99746 390134 62618 32767 3 0x90 piperd syz-executor.4
88247 379916 41211 32767 3 0x90 nanoslp syz-executor.7
62618 54489 45294 0 3 0x82 wait syz-executor.4
41211 195551 45294 0 3 0x82 wait syz-executor.7
24248 483309 45294 0 3 0x82 wait syz-executor.2
67012 30210 58685 32767 3 0x90 piperd syz-executor.5
58685 292266 45294 0 3 0x82 wait syz-executor.5
73774 224175 6294 32767 3 0x90 nanoslp syz-executor.3
6294 471428 45294 0 3 0x82 wait syz-executor.3
84466 476437 83518 32767 3 0x90 piperd syz-executor.6
213 8214 81150 32767 3 0x90 nanoslp syz-executor.1
83518 355812 45294 0 3 0x82 wait syz-executor.6
81150 261206 45294 0 3 0x82 wait syz-executor.1
81640 197330 22877 32767 3 0x90 nanoslp syz-executor.0
22877 36743 45294 0 3 0x82 wait syz-executor.0
45294 514530 14963 0 3 0x82 wait syz-execprog
45294 40024 14963 0 3 0x4000082 nanoslp syz-execprog
45294 25152 14963 0 3 0x4000082 wait syz-execprog
45294 270441 14963 0 3 0x4000082 thrsleep syz-execprog
45294 332690 14963 0 3 0x4000082 wait syz-execprog
45294 130534 14963 0 3 0x4000082 wait syz-execprog
45294 304769 14963 0 3 0x4000082 thrsleep syz-execprog
45294 523562 14963 0 3 0x4000082 thrsleep syz-execprog
45294 280230 14963 0 3 0x4000082 wait syz-execprog
45294 5997 14963 0 3 0x4000082 wait syz-execprog
45294 361879 14963 0 3 0x4000082 wait syz-execprog
45294 443179 14963 0 3 0x4000082 wait syz-execprog
45294 304138 14963 0 3 0x4000082 nanoslp syz-execprog
45294 42535 14963 0 3 0x4000082 thrsleep syz-execprog
45294 468688 14963 0 3 0x4000082 kqread syz-execprog
45294 162890 14963 0 3 0x4000082 thrsleep syz-execprog
14963 124974 22256 0 3 0x10008a sigsusp ksh
22256 62926 15483 0 3 0x9a kqread sshd
76690 273511 1 0 3 0x100083 ttyin getty
15483 46132 1 0 3 0x88 kqread sshd
79021 297233 65991 73 3 0x1100090 kqread syslogd
65991 1484 1 0 3 0x100082 netio syslogd
68249 176392 1 0 3 0x100080 kqread resolvd
35648 196692 70132 77 3 0x100092 kqread dhcpleased
39461 328446 70132 77 3 0x100092 kqread dhcpleased
70132 30344 1 0 3 0x80 kqread dhcpleased
17500 74966 0 0 3 0x14200 bored smr
14863 90414 0 0 3 0x14200 pgzero zerothread
53785 510621 0 0 3 0x14200 aiodoned aiodoned
91279 279798 0 0 3 0x14200 syncer update
79991 503344 0 0 3 0x14200 cleaner cleaner
47483 463471 0 0 3 0x14200 reaper reaper
65628 109682 0 0 3 0x14200 pgdaemon pagedaemon
63136 34679 0 0 3 0x14200 bored viomb
52396 192132 0 0 3 0x40014200 acpi0 acpi0
46177 350009 0 0 3 0x40014200 idle1
58721 171989 0 0 3 0x14200 bored softnet
2772 384124 0 0 3 0x14200 bored softnet
81382 252356 0 0 3 0x14200 bored softnet
69457 330885 0 0 3 0x14200 bored softnet
65533 524122 0 0 3 0x14200 bored systqmp
4723 58190 0 0 3 0x14200 bored systq
62305 300450 0 0 3 0x40014200 bored softclock
94 299189 0 0 3 0x40014200 idle0
1 330821 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
Process 39095 (syz-executor.3) thread 0xffff800021431a40 (32128)
exclusive kernel_lock &kernel_lock r = 1 (0xffffffff82a00740)
#0 witness_lock+0x44d
#1 syscall+0x41d mi_syscall sys/sys/syscall_mi.h:100 [inline]
#1 syscall+0x41d sys/arch/amd64/amd64/trap.c:585
#2 Xsyscall+0x128
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 10173 6407K 6419K 78643K 11263 0
pcb 13 8K 8K 78643K 13 0
rtable 234 6K 6K 78643K 351 0
ifaddr 82 16K 16K 78643K 84 0
counters 56 35K 35K 78643K 56 0
ioctlops 0 0K 2K 78643K 33 0
mount 1 1K 1K 78643K 1 0
log 0 0K 0K 78643K 4 0
vnodes 1166 73K 73K 78643K 1179 0
UFS quota 1 32K 32K 78643K 1 0
UFS mount 5 36K 36K 78643K 5 0
shm 2 1K 1K 78643K 2 0
VM map 2 1K 1K 78643K 2 0
sem 2 0K 0K 78643K 2 0
dirhash 12 2K 2K 78643K 12 0
ACPI 1697 195K 286K 78643K 12548 0
file desc 20 73K 121K 78643K 1304 0
proc 56 78K 103K 78643K 451 0
NFS srvsock 1 0K 0K 78643K 1 0
NFS daemon 1 16K 16K 78643K 1 0
in_multi 99 6K 6K 78643K 99 0
ether_multi 1 0K 0K 78643K 1 0
ISOFS mount 1 32K 32K 78643K 1 0
MSDOSFS mount 1 16K 16K 78643K 1 0
ttys 25 122K 122K 78643K 25 0
exec 0 0K 2K 78643K 627 0
tdb 3 0K 0K 78643K 3 0
pagedep 1 8K 8K 78643K 1 0
inodedep 1 32K 32K 78643K 1 0
newblk 1 0K 0K 78643K 1 0
VM swap 8 62K 62K 78643K 8 0
UVM amap 180 90K 104K 78643K 9649 0
UVM aobj 3 2K 2K 78643K 3 0
memdesc 1 4K 4K 78643K 1 0
crypto data 1 1K 1K 78643K 1 0
NDP 11 0K 2K 78643K 27 0
temp 51 4710K 4774K 78643K 5684 0
kqueue 12 18K 18K 78643K 25 0
SYN cache 2 16K 16K 78643K 2 0
ddb{1}> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache 128 22 0 0 1 0 1 1 0 8 0
rtpcb 120 37 0 34 1 0 1 1 0 8 0
rtentry 112 111 0 1 4 0 4 4 0 8 0
unpcb 144 33 0 20 1 0 1 1 0 8 0
syncache 296 5 0 5 2 2 0 1 0 8 0
tcpcb 768 8 0 5 1 0 1 1 0 8 0
arp 120 18 0 0 1 0 1 1 0 8 0
inpcb 320 57 0 51 1 0 1 1 0 8 0
nd6 48 24 0 0 1 0 1 1 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 452 0 0 29 0 29 29 0 8 0
art_table 32 453 0 0 4 0 4 4 0 8 0
art_node 16 110 0 10 1 0 1 1 0 8 0
dirhash 1024 17 0 0 3 0 3 3 0 8 0
dino2pl 256 3789 0 2355 90 0 90 90 0 8 0
ffsino 272 3789 0 2355 96 0 96 96 0 8 0
nchpl 144 6366 0 4692 63 0 63 63 0 8 0
uvmvnodes 80 3798 0 0 78 0 78 78 0 8 0
vnodes 216 3798 0 0 211 0 211 211 0 8 0
namei 1024 90937 0 90937 3 2 1 2 0 8 1
percpumem 16 40 0 0 1 0 1 1 0 8 0
kstatmem 264 22 0 0 2 0 2 2 0 8 0
scxspl 216 15977 0 15977 22 21 1 8 0 8 1
plimitpl 152 31 0 9 1 0 1 1 0 8 0
sigapl 424 1599 0 1548 7 0 7 7 0 8 0
futexpl 64 6540 0 6539 1 0 1 1 0 8 0
knotepl 120 106 0 0 4 0 4 4 0 8 0
kqueuepl 216 21 0 13 1 0 1 1 0 8 0
pipepl 320 131 0 103 4 1 3 3 0 8 0
fdescpl 496 1582 0 1551 7 2 5 6 0 8 0
filepl 152 80878 0 80748 13 0 13 13 0 8 7
lockfpl 104 2316 0 2312 1 0 1 1 0 8 0
lockfspl 48 1160 0 1156 1 0 1 1 0 8 0
sessionpl 144 25 0 9 1 0 1 1 0 8 0
pgrppl 48 25 0 9 1 0 1 1 0 8 0
ucredpl 104 88 0 70 1 0 1 1 0 8 0
zombiepl 144 1551 0 1548 2 1 1 1 0 8 0
processpl 1064 1599 0 1548 5 1 4 5 0 8 0
procpl 672 3391 0 3322 7 0 7 7 0 8 0
sockpl 488 127 0 105 4 1 3 4 0 8 0
mcl8k 8192 2 0 0 1 0 1 1 0 8 0
mcl4k 4096 4 0 0 1 0 1 1 0 8 0
mcl2k 2048 73 0 0 10 1 9 9 0 8 0
mtagpl 96 1 0 0 1 0 1 1 0 8 0
mbufpl 256 281 0 0 17 0 17 17 0 8 0
bufpl 288 4668 0 127 325 0 325 325 0 8 0
anonpl 24 242385 0 237284 46 9 37 40 0 186 0
amapchunkpl 152 232681 0 231894 56 1 55 55 0 158 24
amappl16 200 2531 0 2427 8 1 7 7 0 8 0
amappl15 192 393 0 386 1 0 1 1 0 8 0
amappl14 184 328 0 322 1 0 1 1 0 8 0
amappl13 176 386 0 382 2 1 1 1 0 8 0
amappl12 168 14 0 8 1 0 1 1 0 8 0
amappl11 160 82 0 68 1 0 1 1 0 8 0
amappl10 152 14 0 14 1 1 0 1 0 8 0
amappl9 144 730 0 723 1 0 1 1 0 8 0
amappl8 136 687 0 647 3 1 2 2 0 8 0
amappl7 128 285 0 264 1 0 1 1 0 8 0
amappl6 120 469 0 456 2 1 1 2 0 8 0
amappl5 112 973 0 956 1 0 1 1 0 8 0
amappl4 104 989 0 959 2 0 2 2 0 8 0
amappl3 96 4063 0 4010 2 0 2 2 0 8 0
amappl2 88 723 0 687 2 1 1 2 0 8 0
amappl1 80 40282 0 39624 21 4 17 19 0 8 0
amappl 88 9207 0 9084 5 1 4 4 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 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 2 0 0 1 0 1 1 0 8 0
uaddrrnd 24 1582 0 1551 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 1582 0 1551 1 0 1 1 0 8 0
vmmpekpl 168 15423 0 15387 2 0 2 2 0 8 0
vmmpepl 168 211382 0 209488 110 6 104 104 0 357 8
vmsppl 368 1581 0 1551 4 0 4 4 0 8 0
rwobjpl 56 40775 0 36018 69 0 69 69 0 8 0
pdppl 4096 3171 0 3102 123 42 81 93 0 8 12
pvpl 32 574215 0 564782 252 21 231 245 0 265 143
pmappl 248 1581 0 1551 4 1 3 3 0 8 0
extentpl 40 56 0 38 1 0 1 1 0 8 0
phpool 112 706 0 47 19 0 19 19 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp
x86_ipi_db(ffffffff8294aff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 sys/kern/kern_lock.c:147
softintr_dispatch(0) at softintr_dispatch+0x4e sys/arch/amd64/amd64/softintr.c:88
Xsoftclock() at Xsoftclock+0x1f
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 sys/kern/kern_lock.c:147
syscall(ffff800021487b30) at syscall+0x41d mi_syscall sys/sys/syscall_mi.h:100 [inline]
syscall(ffff800021487b30) at syscall+0x41d sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffc6850, count: 6
ddb{0}> trace
x86_ipi_db(ffffffff8294aff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 sys/kern/kern_lock.c:147
softintr_dispatch(0) at softintr_dispatch+0x4e sys/arch/amd64/amd64/softintr.c:88
Xsoftclock() at Xsoftclock+0x1f
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82a00538) at __mp_lock+0x122 sys/kern/kern_lock.c:147
syscall(ffff800021487b30) at syscall+0x41d mi_syscall sys/sys/syscall_mi.h:100 [inline]
syscall(ffff800021487b30) at syscall+0x41d sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffc6850, count: -9
ddb{0}> machine ddbcpu 1
Stopped at db_enter+0x18: addq $0x8,%rsp
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a14e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff82617e14,ffffffff82639607,ea,ffffffff826320a6) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a846368,6) at uvn_attach+0x444 sys/uvm/uvm_vnode.c:234
uvm_mmapfile(fffffd8075116468,ffff8000214b75e8,10000,2,6,11,eb3fbe5eda94103,fffffd8075116468,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff800021431a40,ffff8000214b7690,ffff8000214b7760) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff800021431a40,ffff8000214b7718,ffff8000214b7760) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff8000214b77e0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff8000214b77e0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0b6ce60f0, count: 6
ddb{1}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a14e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff82617e14,ffffffff82639607,ea,ffffffff826320a6) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a846368,6) at uvn_attach+0x444 sys/uvm/uvm_vnode.c:234
uvm_mmapfile(fffffd8075116468,ffff8000214b75e8,10000,2,6,11,eb3fbe5eda94103,fffffd8075116468,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff800021431a40,ffff8000214b7690,ffff8000214b7760) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff800021431a40,ffff8000214b7718,ffff8000214b7760) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff8000214b77e0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff8000214b77e0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0b6ce60f0, count: -9