panic: kernel diagnostic assertion "uvn->u_obj.uo_refs == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/uvm/uvm_vnode.c", line 235
Stopped at db_enter+0x18: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
277422 64346 0 0 0 1 syz-executor.0
*380328 64346 0 0 0x4000000 0K syz-executor.0
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a55e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff8261b443,ffffffff8263e6a2,eb,ffffffff82637043) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a6b11c8,6) at uvn_attach+0x454 sys/uvm/uvm_vnode.c:235
uvm_mmapfile(fffffd806f090008,ffff8000213189f8,10000,2,6,11,445f8279a03234d4,fffffd806f090008,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff8000ffff4fc0,ffff800021318aa0,ffff800021318b70) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff8000ffff4fc0,ffff800021318b28,ffff800021318b70) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff800021318bf0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff800021318bf0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x9190dffa090, 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{0}>
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: kernel diagnostic assertion "uvn->u_obj.uo_refs == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/uvm/uvm_vnode.c", line 235
ddb{0}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a55e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff8261b443,ffffffff8263e6a2,eb,ffffffff82637043) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a6b11c8,6) at uvn_attach+0x454 sys/uvm/uvm_vnode.c:235
uvm_mmapfile(fffffd806f090008,ffff8000213189f8,10000,2,6,11,445f8279a03234d4,fffffd806f090008,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff8000ffff4fc0,ffff800021318aa0,ffff800021318b70) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff8000ffff4fc0,ffff800021318b28,ffff800021318b70) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff800021318bf0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff800021318bf0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x9190dffa090, count: -9
ddb{0}> show registers
rdi 0
rsi 0x1
rbp 0xffff800021318690
rbx 0xffffffff8296db8f cpu_info_full_primary+0x2b8f
rdx 0x3fd
rcx 0
rax 0x8c
r8 0x101010101010101
r9 0x8080808080808080
r10 0x1ca017bc31a6ac42
r11 0x39324836b7e5cadb
r12 0xffffffff8296d990 cpu_info_full_primary+0x2990
r13 0
r14 0
r15 0x1
rip 0xffffffff8228a448 db_enter+0x18
cs 0x8
rflags 0x246
rsp 0xffff800021318680
ss 0x10
db_enter+0x18: addq $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor.0) pid=380328 stat=onproc
flags process=0 proc=4000000<THREAD>
pri=32, usrpri=86, nice=20
forw=0xffffffffffffffff, list=0xffff8000ffff4d20,0xffff8000ffff5cf0
process=0xffff8000ffff8008 user=0xffff800021313000, vmspace=0xfffffd806f090008
estcpu=36, cpticks=2, pctcpu=0.0
user=0, sys=1, intr=0
ddb{0}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
64346 277422 69735 0 7 0 syz-executor.0
*64346 380328 69735 0 7 0x4000000 syz-executor.0
64346 145777 69735 0 2 0x4000000 syz-executor.0
69735 194909 72704 0 2 0x482 syz-executor.0
72704 220828 36184 0 3 0x82 thrsleep syz-execprog
72704 151884 36184 0 2 0x4000482 syz-execprog
72704 508581 36184 0 3 0x4000082 thrsleep syz-execprog
72704 43472 36184 0 3 0x4000082 wait syz-execprog
72704 61391 36184 0 3 0x4000082 kqread syz-execprog
72704 465187 36184 0 3 0x4000082 thrsleep syz-execprog
72704 366317 36184 0 3 0x4000082 thrsleep syz-execprog
72704 1164 36184 0 3 0x4000082 thrsleep syz-execprog
72704 394231 36184 0 3 0x4000082 thrsleep syz-execprog
36184 261147 82921 0 3 0x10008a sigsusp ksh
82921 56518 23031 0 3 0x9a kqread sshd
94567 156858 1 0 3 0x100083 ttyin getty
23031 54032 1 0 3 0x88 kqread sshd
63430 26484 77118 73 3 0x1100090 kqread syslogd
77118 373677 1 0 3 0x100082 netio syslogd
59131 508110 1 0 3 0x100080 kqread resolvd
77273 133465 79829 77 3 0x100092 kqread dhcpleased
27407 143588 79829 77 3 0x100092 kqread dhcpleased
79829 65990 1 0 3 0x80 kqread dhcpleased
39854 76154 0 0 3 0x14200 bored smr
8378 377605 0 0 3 0x14200 pgzero zerothread
82246 269044 0 0 3 0x14200 aiodoned aiodoned
37955 137228 0 0 3 0x14200 syncer update
93501 436937 0 0 3 0x14200 cleaner cleaner
5751 466781 0 0 3 0x14200 reaper reaper
78903 204130 0 0 3 0x14200 pgdaemon pagedaemon
85964 166911 0 0 3 0x14200 bored viomb
1023 263336 0 0 3 0x40014200 acpi0 acpi0
98723 196445 0 0 3 0x40014200 idle1
30470 329270 0 0 3 0x14200 bored softnet
43839 112708 0 0 3 0x14200 bored softnet
21365 305061 0 0 3 0x14200 bored softnet
13510 400119 0 0 3 0x14200 bored softnet
96389 289102 0 0 3 0x14200 bored systqmp
72206 341334 0 0 3 0x14200 bored systq
84552 398927 0 0 3 0x40014200 bored softclock
28369 65273 0 0 3 0x40014200 idle0
1 326184 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{0}> show all locks
Process 64346 (syz-executor.0) thread 0xffff8000ffff4d20 (277422)
exclusive rwlock uobjlk r = 0 (0xfffffd806a22cd38)
#0 witness_lock+0x44d
#1 rw_enter+0x3e1 sys/kern/kern_rwlock.c:310
#2 uvm_fault_lower+0x951 sys/uvm/uvm_fault.c:1324
#3 uvm_fault+0x238
#4 upageflttrap+0x82 sys/arch/amd64/amd64/trap.c:181
#5 usertrap+0x1aa sys/arch/amd64/amd64/trap.c:403
#6 recall_trap+0x8
Process 64346 (syz-executor.0) thread 0xffff8000ffff4fc0 (380328)
exclusive kernel_lock &kernel_lock r = 1 (0xffffffff82ba5240)
#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{0}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 10158 6391K 6420K 78643K 11248 0
pcb 13 8K 8K 78643K 13 0
rtable 80 2K 2K 78643K 133 0
ifaddr 33 8K 8K 78643K 33 0
counters 42 33K 33K 78643K 42 0
ioctlops 0 0K 2K 78643K 26 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 4 9K 13K 78643K 263 0
proc 55 78K 91K 78643K 254 0
NFS srvsock 1 0K 0K 78643K 1 0
NFS daemon 1 16K 16K 78643K 1 0
in_multi 22 1K 1K 78643K 22 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 440 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 64K 78643K 10 0
UVM amap 122 27K 27K 78643K 3453 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 4 0K 0K 78643K 6 0
temp 23 4717K 4781K 78643K 3293 0
kqueue 12 18K 18K 78643K 25 0
SYN cache 2 16K 16K 78643K 2 0
ddb{0}> 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 19 0 16 1 0 1 1 0 8 0
rtentry 112 34 0 1 1 0 1 1 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 4 0 0 1 0 1 1 0 8 0
inpcb 368 29 0 23 1 0 1 1 0 8 0
nd6 48 3 0 0 1 0 1 1 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 144 0 0 9 0 9 9 0 8 0
art_table 32 145 0 0 2 0 2 2 0 8 0
art_node 16 33 0 3 1 0 1 1 0 8 0
dirhash 1024 17 0 0 3 0 3 3 0 8 0
dino2pl 256 1927 0 531 88 0 88 88 0 8 0
ffsino 272 1927 0 531 94 0 94 94 0 8 0
nchpl 144 2645 0 1025 61 0 61 61 0 8 0
uvmvnodes 80 1936 0 0 40 0 40 40 0 8 0
vnodes 216 1936 0 0 108 0 108 108 0 8 0
namei 1024 6546 0 6546 3 1 2 2 0 8 2
percpumem 16 33 0 0 1 0 1 1 0 8 0
kstatmem 264 8 0 0 1 0 1 1 0 8 0
scxspl 216 8218 0 8218 20 19 1 8 0 8 1
plimitpl 152 17 0 9 1 0 1 1 0 8 0
sigapl 424 564 0 532 5 0 5 5 0 8 1
futexpl 64 1190 0 1190 1 0 1 1 0 8 1
knotepl 120 56 0 0 2 0 2 2 0 8 0
kqueuepl 216 21 0 13 1 0 1 1 0 8 0
pipepl 320 99 0 92 2 1 1 1 0 8 0
fdescpl 496 547 0 532 4 1 3 3 0 8 1
filepl 152 2007 0 1941 4 1 3 4 0 8 0
lockfpl 104 491 0 488 1 0 1 1 0 8 0
lockfspl 48 247 0 244 1 0 1 1 0 8 0
sessionpl 144 18 0 9 1 0 1 1 0 8 0
pgrppl 48 18 0 9 1 0 1 1 0 8 0
ucredpl 104 64 0 54 1 0 1 1 0 8 0
zombiepl 144 532 0 532 2 1 1 1 0 8 1
processpl 1064 564 0 532 3 0 3 3 0 8 0
procpl 672 1070 0 1028 4 0 4 4 0 8 0
sockpl 488 81 0 59 3 0 3 3 0 8 0
mcl8k 8192 3 0 0 1 0 1 1 0 8 0
mcl4k 4096 3 0 0 1 0 1 1 0 8 0
mcl2k 2048 65 0 0 9 0 9 9 0 8 0
mtagpl 96 2 0 0 1 0 1 1 0 8 0
mbufpl 256 134 0 0 8 0 8 8 0 8 0
bufpl 288 4379 0 133 304 0 304 304 0 8 0
anonpl 24 94193 0 89977 49 4 45 45 0 186 19
amapchunkpl 152 51525 0 51054 20 1 19 19 0 158 0
amappl16 200 652 0 581 6 1 5 5 0 8 0
amappl15 192 79 0 71 1 0 1 1 0 8 0
amappl14 184 7 0 6 1 0 1 1 0 8 0
amappl13 176 39 0 37 2 1 1 1 0 8 0
amappl12 168 246 0 244 2 1 1 1 0 8 0
amappl11 160 42 0 29 1 0 1 1 0 8 0
amappl10 152 13 0 13 1 0 1 1 0 8 1
amappl9 144 907 0 905 2 1 1 1 0 8 0
amappl8 136 430 0 408 2 0 2 2 0 8 0
amappl7 128 85 0 74 1 0 1 1 0 8 0
amappl6 120 170 0 152 2 0 2 2 0 8 1
amappl5 112 328 0 320 1 0 1 1 0 8 0
amappl4 104 627 0 606 2 0 2 2 0 8 1
amappl3 96 1525 0 1492 2 0 2 2 0 8 1
amappl2 88 650 0 601 4 1 3 3 0 8 1
amappl1 80 16231 0 15696 23 2 21 21 0 8 8
amappl 88 3117 0 3038 4 1 3 3 0 92 1
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 24 547 0 532 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 547 0 532 1 0 1 1 0 8 0
vmmpekpl 168 9862 0 9844 2 0 2 2 0 8 1
vmmpepl 168 61237 0 59936 100 3 97 97 0 357 40
vmsppl 368 546 0 532 3 0 3 3 0 8 1
rwobjpl 56 17912 0 15135 42 0 42 42 0 8 2
pdppl 4096 1101 0 1064 71 28 43 53 0 8 6
pvpl 32 280224 0 271969 276 6 270 270 0 265 202
pmappl 248 546 0 532 3 1 2 2 0 8 1
extentpl 40 56 0 38 1 0 1 1 0 8 0
phpool 112 599 0 31 17 0 17 17 0 8 0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff825a55e6) at panic+0x177 sys/kern/subr_prf.c:198
__assert(ffffffff8261b443,ffffffff8263e6a2,eb,ffffffff82637043) at __assert+0x25 sys/kern/subr_prf.c:157
uvn_attach(fffffd806a6b11c8,6) at uvn_attach+0x454 sys/uvm/uvm_vnode.c:235
uvm_mmapfile(fffffd806f090008,ffff8000213189f8,10000,2,6,11,445f8279a03234d4,fffffd806f090008,0,11) at uvm_mmapfile+0x194 sys/uvm/uvm_mmap.c:1029
sys_mmap(ffff8000ffff4fc0,ffff800021318aa0,ffff800021318b70) at sys_mmap+0xb4a sys/uvm/uvm_mmap.c:395
sys_pad_mmap(ffff8000ffff4fc0,ffff800021318b28,ffff800021318b70) at sys_pad_mmap+0x68 sys/uvm/uvm_mmap.c:470
syscall(ffff800021318bf0) at syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff800021318bf0) at syscall+0x435 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x9190dffa090, count: -9
ddb{0}> machine ddbcpu 1
Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp
x86_ipi_db(ffff800020dd8ff0) 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(ffffffff82ba5038) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82ba5038) at __mp_lock+0x122 sys/kern/kern_lock.c:147
syscall(ffff80002130a350) at syscall+0x41d mi_syscall sys/sys/syscall_mi.h:100 [inline]
syscall(ffff80002130a350) at syscall+0x41d sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffbc140, count: 9
ddb{1}> trace
x86_ipi_db(ffff800020dd8ff0) 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(ffffffff82ba5038) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline]
__mp_lock(ffffffff82ba5038) at __mp_lock+0x122 sys/kern/kern_lock.c:147
syscall(ffff80002130a350) at syscall+0x41d mi_syscall sys/sys/syscall_mi.h:100 [inline]
syscall(ffff80002130a350) at syscall+0x41d sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffbc140, count: -6