panic: vput: v_writecount != 0 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *343042 52182 0 0x2 0x4000000 1K syz-executor3546 385272 52182 0 0x2 0x4000000 0 syz-executor3546 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 vput(fffffd806fbe28a8) at vput+0x187 sys/kern/vfs_subr.c:759 vn_closefile(fffffd80739f1558,ffff800020b60778) at vn_closefile+0x15b sys/kern/vfs_vnops.c:583 fdrop(fffffd80739f1558,ffff800020b60778) at fdrop+0xc9 sys/kern/kern_descrip.c:1269 closef(fffffd80739f1558,ffff800020b60778) at closef+0x11d sys/kern/kern_descrip.c:1253 finishdup(ffff800020b60778,fffffd80739f1ab0,5,4,ffff800020bb0f30,1) at finishdup+0x2b6 sys/kern/kern_descrip.c:682 dodup3(ffff800020b60778,5,4,0,ffff800020bb0f30) at dodup3+0x5c5 sys/kern/kern_descrip.c:377 syscall(ffff800020bb0fa0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020bb0fa0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,d57649310c8,0,d57649310a8,d57649310a0) at Xsyscall+0x128 end of kernel end trace frame: 0xd5a444b1250, count: 5 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 vput: v_writecount != 0 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 vput(fffffd806fbe28a8) at vput+0x187 sys/kern/vfs_subr.c:759 vn_closefile(fffffd80739f1558,ffff800020b60778) at vn_closefile+0x15b sys/kern/vfs_vnops.c:583 fdrop(fffffd80739f1558,ffff800020b60778) at fdrop+0xc9 sys/kern/kern_descrip.c:1269 closef(fffffd80739f1558,ffff800020b60778) at closef+0x11d sys/kern/kern_descrip.c:1253 finishdup(ffff800020b60778,fffffd80739f1ab0,5,4,ffff800020bb0f30,1) at finishdup+0x2b6 sys/kern/kern_descrip.c:682 dodup3(ffff800020b60778,5,4,0,ffff800020bb0f30) at dodup3+0x5c5 sys/kern/kern_descrip.c:377 syscall(ffff800020bb0fa0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020bb0fa0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,d57649310c8,0,d57649310a8,d57649310a0) at Xsyscall+0x128 end of kernel end trace frame: 0xd5a444b1250, count: -10 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020bb0b60 rbx 0xffff800020bb0c10 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffffffff810fe383 kprintf+0x173 r9 0x1 r10 0xc6e378f897b7ab32 r11 0x13a8e4cbfc24ce31 r12 0x3000000008 r13 0xffff800020bb0b70 r14 0x100 r15 0x1 rip 0xffffffff813f8388 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020bb0b50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor3546) pid=343042 stat=onproc flags process=2 proc=4000000 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020b60500,0xffff800020b61168 process=0xffff800020b2b890 user=0xffff800020bac000, vmspace=0xfffffd806e7ffb88 estcpu=0, cpticks=3, pctcpu=0.0 user=0, sys=3, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 52182 285429 28407 0 2 0x2 syz-executor3546 *52182 343042 28407 0 7 0x4000002 syz-executor3546 52182 385272 28407 0 7 0x4000002 syz-executor3546 52182 405141 28407 0 3 0x4000082 fsleep syz-executor3546 28407 493611 57876 0 3 0x10008a pause ksh 57876 504283 59973 0 3 0x92 select sshd 79334 484390 1 0 3 0x100083 ttyin getty 59973 448246 1 0 3 0x80 select sshd 86142 279575 96140 74 3 0x100092 bpf pflogd 96140 252745 1 0 3 0x80 netio pflogd 50077 267536 56216 73 3 0x100090 kqread syslogd 56216 485677 1 0 3 0x100082 netio syslogd 7259 414662 1 77 3 0x100090 poll dhclient 59653 354381 1 0 3 0x80 poll dhclient 95526 421686 0 0 2 0x14200 zerothread 18060 396887 0 0 3 0x14200 aiodoned aiodoned 72987 13600 0 0 3 0x14200 syncer update 11601 443441 0 0 3 0x14200 cleaner cleaner 95967 71678 0 0 3 0x14200 reaper reaper 53677 463976 0 0 3 0x14200 pgdaemon pagedaemon 79625 101036 0 0 3 0x14200 bored crynlk 95903 403288 0 0 3 0x14200 bored crypto 88527 245058 0 0 3 0x40014200 acpi0 acpi0 53368 128566 0 0 3 0x40014200 idle1 12459 385885 0 0 3 0x14200 bored softnet 40031 217364 0 0 3 0x14200 bored systqmp 88657 519499 0 0 3 0x14200 bored systq 64224 322875 0 0 3 0x40014200 bored softclock 17821 113176 0 0 3 0x40014200 idle0 48983 393327 0 0 3 0x14200 bored smr 1 447981 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 52182 (syz-executor3546) thread 0xffff800020b60778 (343042) exclusive rrwlock inode r = 0 (0xfffffd806db60b48) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x46d sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:602 #4 vn_closefile+0x119 vn_lock sys/kern/vfs_vnops.c:556 [inline] #4 vn_closefile+0x119 vn_close sys/kern/vfs_vnops.c:288 [inline] #4 vn_closefile+0x119 sys/kern/vfs_vnops.c:582 #5 fdrop+0xc9 sys/kern/kern_descrip.c:1269 #6 closef+0x11d sys/kern/kern_descrip.c:1253 #7 finishdup+0x2b6 sys/kern/kern_descrip.c:682 #8 dodup3+0x5c5 sys/kern/kern_descrip.c:377 #9 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #9 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #10 Xsyscall+0x128 exclusive rwlock fdlock r = 0 (0xfffffd806f11d9e8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 dodup3+0x1a1 sys/kern/kern_descrip.c:362 #2 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #2 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #3 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 2 (0xffffffff82381420) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 syscall+0x412 mi_syscall sys/sys/syscall_mi.h:83 [inline] #1 syscall+0x412 sys/arch/amd64/amd64/trap.c:555 #2 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9452 6383K 6385K 78643K 10541 0 0 pcb 13 8K 8K 78643K 13 0 0 rtable 61 2K 2K 78643K 125 0 0 ifaddr 25 7K 7K 78643K 26 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1467 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1182 74K 74K 78643K 1187 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 2 0K 0K 78643K 2 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 1 0K 0K 78643K 1 0 0 proc 52 50K 58K 78643K 334 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 in_multi 11 0K 0K 78643K 11 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 18 79K 79K 78643K 18 0 0 exec 0 0K 1K 78643K 179 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 64 3K 3K 78643K 821 0 0 UVM aobj 2 2K 2K 78643K 2 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 4 0K 0K 78643K 4 0 0 temp 39 2728K 2792K 78643K 1993 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 2 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 15 0 13 1 0 1 1 0 8 0 rtentry 112 23 0 1 1 0 1 1 0 8 0 unpcb 120 31 0 19 1 0 1 1 0 8 0 syncache 264 5 0 5 1 0 1 1 0 8 1 tcpqe 32 9 0 9 1 1 0 1 0 8 0 tcpcb 544 8 0 5 1 0 1 1 0 8 0 inpcb 280 29 0 23 1 0 1 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 8 0 0 1 0 1 1 0 8 0 pfstkey 112 8 0 0 1 0 1 1 0 8 0 pfstate 328 8 0 0 1 0 1 1 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 97 0 0 7 0 7 7 0 8 0 art_table 32 98 0 0 1 0 1 1 0 8 0 art_node 16 22 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1402 0 18 45 0 45 45 0 8 0 ffsino 272 1402 0 18 93 0 93 93 0 8 0 nchpl 144 1587 0 45 58 0 58 58 0 8 0 uvmvnodes 72 1412 0 0 26 0 26 26 0 8 0 vnodes 200 1412 0 0 75 0 75 75 0 8 0 namei 1024 3650 0 3650 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 2341 0 2341 2 1 1 2 0 8 1 plimitpl 152 14 0 8 1 0 1 1 0 8 0 sigapl 432 205 0 193 2 0 2 2 0 8 0 futexpl 56 5 0 4 1 0 1 1 0 8 0 knotepl 112 5 0 0 1 0 1 1 0 8 0 kqueuepl 104 1 0 0 1 0 1 1 0 8 0 pipepl 112 134 0 127 2 1 1 1 0 8 0 fdescpl 488 206 0 193 3 0 3 3 0 8 0 filepl 152 987 0 936 2 0 2 2 0 8 0 lockfpl 104 6 0 6 1 1 0 1 0 8 0 lockfspl 48 3 0 3 1 1 0 1 0 8 0 sessionpl 112 18 0 9 1 0 1 1 0 8 0 pgrppl 48 18 0 9 1 0 1 1 0 8 0 ucredpl 96 52 0 43 1 0 1 1 0 8 0 zombiepl 144 193 0 193 2 1 1 1 0 8 1 processpl 896 221 0 193 4 0 4 4 0 8 0 procpl 632 224 0 193 3 0 3 3 0 8 0 sockpl 384 75 0 55 2 0 2 2 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 78 0 0 10 0 10 10 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 97 0 0 7 0 7 7 0 8 0 bufpl 256 2175 0 276 119 0 119 119 0 8 0 anonpl 16 20177 0 18869 8 2 6 7 0 125 0 amapchunkpl 152 547 0 504 2 0 2 2 0 158 0 amappl16 192 88 0 81 1 0 1 1 0 8 0 amappl14 176 38 0 34 1 0 1 1 0 8 0 amappl12 160 11 0 11 1 1 0 1 0 8 0 amappl11 152 47 0 32 1 0 1 1 0 8 0 amappl10 144 57 0 55 1 0 1 1 0 8 0 amappl9 136 434 0 433 1 0 1 1 0 8 0 amappl8 128 102 0 96 1 0 1 1 0 8 0 amappl7 120 19 0 18 1 0 1 1 0 8 0 amappl6 112 47 0 42 1 0 1 1 0 8 0 amappl5 104 128 0 115 1 0 1 1 0 8 0 amappl4 96 474 0 447 1 0 1 1 0 8 0 amappl3 88 154 0 143 1 0 1 1 0 8 0 amappl2 80 827 0 765 3 1 2 2 0 8 0 amappl1 72 13855 0 13410 15 5 10 15 0 8 0 amappl 80 426 0 402 1 0 1 1 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 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 206 0 193 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 206 0 193 1 0 1 1 0 8 0 vmmpekpl 168 5620 0 5600 1 0 1 1 0 8 0 vmmpepl 168 29316 0 28421 47 8 39 47 0 357 0 vmsppl 368 205 0 193 2 0 2 2 0 8 0 pdppl 4096 420 0 386 6 0 6 6 0 8 0 pvpl 32 80698 0 77625 31 3 28 28 0 265 3 pmappl 232 205 0 193 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 255 0 3 8 0 8 8 0 8 0 ddb{1}>