witness: userret: returning with the following locks held: exclusive rrwlock inode r = 0 (0xfffffd8064f22098) #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_lock+0x6e sys/kern/vfs_vnops.c:556 #5 sys_fchmod+0x160 sys/kern/vfs_syscalls.c:2294 #6 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #6 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #7 Xsyscall+0x128 panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *147495 51090 32767 0x1010 0x4080000 1 syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 witness_warn(2,0,ffffffff81fbb1ca) at witness_warn+0x69e witness_debugger sys/kern/subr_witness.c:2509 [inline] witness_warn(2,0,ffffffff81fbb1ca) at witness_warn+0x69e sys/kern/subr_witness.c:1454 userret(ffff800020b28510) at userret+0x36a sys/kern/kern_sig.c:1911 syscall(ffff8000250192b0) at syscall+0x44a mi_syscall_return sys/sys/syscall_mi.h:115 [inline] syscall(ffff8000250192b0) at syscall+0x44a sys/arch/amd64/amd64/trap.c:577 Xsyscall(6,9,fffffffffffffedd,0,2,9c2ea9221b0) at Xsyscall+0x128 end of kernel end trace frame: 0x9c595a9abb0, count: 9 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 witness_warn 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 witness_warn(2,0,ffffffff81fbb1ca) at witness_warn+0x69e witness_debugger sys/kern/subr_witness.c:2509 [inline] witness_warn(2,0,ffffffff81fbb1ca) at witness_warn+0x69e sys/kern/subr_witness.c:1454 userret(ffff800020b28510) at userret+0x36a sys/kern/kern_sig.c:1911 syscall(ffff8000250192b0) at syscall+0x44a mi_syscall_return sys/sys/syscall_mi.h:115 [inline] syscall(ffff8000250192b0) at syscall+0x44a sys/arch/amd64/amd64/trap.c:577 Xsyscall(6,9,fffffffffffffedd,0,2,9c2ea9221b0) at Xsyscall+0x128 end of kernel end trace frame: 0x9c595a9abb0, count: -6 ddb{1}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800025018ff0 rbx 0xffff8000250190a0 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800021c02000 rax 0xffff8000009f36c0 r8 0xffffffff81ecbe33 kprintf+0x173 r9 0x1 r10 0x25 r11 0x58343f7437e8d836 r12 0x3000000008 r13 0xffff800025019000 r14 0x100 r15 0x1 rip 0xffffffff8121eda8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800025018fe0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=147495 stat=onproc flags process=1010 proc=4080000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b29b48,0xffffffff82379b48 process=0xffff800020b7c380 user=0xffff800025014000, vmspace=0xfffffd806e904458 estcpu=36, cpticks=5, pctcpu=0.0 user=0, sys=5, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 51090 79418 84537 32767 3 0x3010 suspend syz-executor.0 *51090 147495 84537 32767 7 0x4081010 syz-executor.0 32004 180171 48908 32767 2 0x10 syz-executor.1 48908 465741 14514 0 3 0x82 wait syz-executor.1 84537 226188 79551 32767 3 0x90 nanosleep syz-executor.0 79551 335052 14514 0 3 0x82 wait syz-executor.0 14122 116344 0 0 3 0x14200 bored sosplice 14514 202034 89625 0 3 0x82 thrsleep syz-fuzzer 14514 283161 89625 0 3 0x4000082 nanosleep syz-fuzzer 14514 282680 89625 0 3 0x4000082 thrsleep syz-fuzzer 14514 296062 89625 0 2 0x4000482 syz-fuzzer 14514 289040 89625 0 3 0x4000082 thrsleep syz-fuzzer 14514 426605 89625 0 3 0x4000082 thrsleep syz-fuzzer 14514 326337 89625 0 3 0x4000082 thrsleep syz-fuzzer 14514 205075 89625 0 3 0x4000082 thrsleep syz-fuzzer 14514 465998 89625 0 3 0x4000082 kqread syz-fuzzer 14514 339038 89625 0 3 0x4000082 thrsleep syz-fuzzer 89625 74140 42601 0 3 0x10008a pause ksh 42601 341684 28166 0 3 0x92 select sshd 81489 153815 1 0 3 0x100083 ttyin getty 28166 345155 1 0 3 0x80 select sshd 43293 225738 66993 73 2 0x100090 syslogd 66993 508737 1 0 3 0x100082 netio syslogd 66832 521855 1 77 3 0x100090 poll dhclient 24830 324449 1 0 3 0x80 poll dhclient 28295 461233 0 0 3 0x14200 pgzero zerothread 36182 227495 0 0 3 0x14200 aiodoned aiodoned 89157 291505 0 0 3 0x14200 syncer update 31169 496077 0 0 3 0x14200 cleaner cleaner 83068 351812 0 0 2 0x14200 reaper 72301 55523 0 0 3 0x14200 pgdaemon pagedaemon 34150 143327 0 0 3 0x14200 bored crynlk 21764 250158 0 0 3 0x14200 bored crypto 64954 440074 0 0 3 0x40014200 acpi0 acpi0 3167 127836 0 0 3 0x40014200 idle1 70363 420417 0 0 3 0x14200 bored softnet 12989 215280 0 0 3 0x14200 bored systqmp 902 437541 0 0 3 0x14200 bored systq 63609 41358 0 0 3 0x40014200 bored softclock 51421 489640 0 0 7 0x40014200 idle0 25666 278088 0 0 3 0x14200 bored smr 1 503526 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 51090 (syz-executor.0) thread 0xffff800020b28510 (147495) exclusive rrwlock inode r = 0 (0xfffffd8064f22098) #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_lock+0x6e sys/kern/vfs_vnops.c:556 #5 sys_fchmod+0x160 sys/kern/vfs_syscalls.c:2294 #6 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #6 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #7 Xsyscall+0x128 Process 32004 (syz-executor.1) thread 0xffff800020b28788 (180171) exclusive rrwlock inode r = 0 (0xfffffd8064f22a28) #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_lock+0x6e sys/kern/vfs_vnops.c:556 #5 vget+0x1c3 sys/kern/vfs_subr.c:672 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1323 #8 ufs_lookup+0x1575 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:90 #10 vfs_lookup+0x7a5 sys/kern/vfs_lookup.c:567 #11 namei+0x61c sys/kern/vfs_lookup.c:248 #12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1768 #13 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #13 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd8064f223c8) #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_lock+0x6e sys/kern/vfs_vnops.c:556 #5 vfs_lookup+0xec sys/kern/vfs_lookup.c:418 #6 namei+0x61c sys/kern/vfs_lookup.c:248 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1768 #8 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #9 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9462 6321K 6321K 78643K 11494 0 0 pcb 13 8K 8K 78643K 13 0 0 rtable 105 3K 3K 78643K 8678 0 0 ifaddr 37 14K 15K 78643K 1203 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 470 0 0 iov 0 0K 32K 78643K 749 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1215 76K 76K 78643K 5843 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 111 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 910 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 7 21K 33K 78643K 9881 0 0 sigio 0 0K 0K 78643K 112 0 0 proc 41 38K 70K 78643K 8859 0 0 subproc 34 2K 2K 78643K 3247 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 1221 0 0 in_multi 33 2K 2K 78643K 2421 0 0 ether_multi 1 0K 0K 78643K 60 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 60 265K 265K 78643K 60 0 0 exec 0 0K 1K 78643K 3380 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 101 21K 31K 78643K 33610 0 0 UVM aobj 130 4K 4K 78643K 156 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 536 0 0 NDP 7 0K 0K 78643K 576 0 0 temp 121 2746K 2842K 78643K 45506 0 0 kqueue 0 0K 0K 78643K 112 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 64 391 0 385 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 861 0 859 1 0 1 1 0 8 0 rtentry 112 2131 0 2087 2 0 2 2 0 8 0 unpcb 120 3640 0 3632 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 4621 0 4621 2 2 0 2 0 8 0 tcpcb 544 2180 0 2176 1 0 1 1 0 8 0 inpcb 280 5255 0 5248 5 3 2 2 0 8 1 nd6 48 573 0 567 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 8742 0 8551 23 10 13 13 0 8 1 art_table 32 8743 0 8551 2 0 2 2 0 8 0 art_node 16 2130 0 2090 1 0 1 1 0 8 0 sysvmsgpl 40 18 0 9 2 1 1 1 0 8 0 semapl 112 908 0 898 1 0 1 1 0 8 0 shmpl 112 154 0 26 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 11287 0 9818 48 0 48 48 0 8 0 ffsino 272 11287 0 9818 100 1 99 99 0 8 0 nchpl 144 22652 0 21023 61 0 61 61 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 200 5926 0 0 312 0 312 312 0 8 0 namei 1024 93270 0 93270 6 5 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 65294 0 65294 34 30 4 6 0 8 4 plimitpl 152 1636 0 1627 1 0 1 1 0 8 0 sigapl 432 9485 0 9470 16 13 3 3 0 8 1 futexpl 56 83852 0 83852 4 3 1 1 0 8 1 knotepl 112 5903 0 5884 1 0 1 1 0 8 0 kqueuepl 104 2219 0 2217 1 0 1 1 0 8 0 pipepl 112 6234 0 6215 15 14 1 2 0 8 0 fdescpl 488 9486 0 9470 3 0 3 3 0 8 0 filepl 152 56542 0 56439 27 22 5 7 0 8 0 lockfpl 104 1766 0 1766 15 14 1 1 0 8 1 lockfspl 48 566 0 566 15 14 1 1 0 8 1 sessionpl 112 206 0 196 1 0 1 1 0 8 0 pgrppl 48 319 0 309 1 0 1 1 0 8 0 ucredpl 96 15280 0 15271 1 0 1 1 0 8 0 zombiepl 144 9471 0 9470 5 4 1 1 0 8 0 processpl 896 9502 0 9470 4 0 4 4 0 8 0 procpl 632 24964 0 24920 38 33 5 5 0 8 1 srpgc 64 378 0 378 28 27 1 1 0 8 1 sosppl 128 157 0 157 30 29 1 1 0 8 1 sockpl 384 9933 0 9916 15 12 3 4 0 8 1 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 9 0 0 2 0 2 2 0 8 0 mcl12k 12288 41 0 0 2 0 2 2 0 8 0 mcl9k 9216 31 0 0 2 0 2 2 0 8 0 mcl8k 8192 25 0 0 4 1 3 3 0 8 0 mcl4k 4096 25 0 0 4 1 3 3 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 219 0 0 24 7 17 24 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 751 0 0 13 0 13 13 0 8 0 bufpl 256 19214 0 12190 440 0 440 440 0 8 0 anonpl 16 979952 0 973622 161 124 37 46 0 125 0 amapchunkpl 152 78531 0 78443 142 131 11 18 0 158 6 amappl16 192 39795 0 39424 230 207 23 32 0 8 2 amappl15 184 902 0 901 1 0 1 1 0 8 0 amappl14 176 2516 0 2506 1 0 1 1 0 8 0 amappl13 168 1623 0 1623 23 22 1 1 0 8 1 amappl12 160 966 0 962 1 0 1 1 0 8 0 amappl11 152 1353 0 1342 1 0 1 1 0 8 0 amappl10 144 1516 0 1515 1 0 1 1 0 8 0 amappl9 136 4086 0 4083 1 0 1 1 0 8 0 amappl8 128 2942 0 2912 3 1 2 2 0 8 0 amappl7 120 1857 0 1848 1 0 1 1 0 8 0 amappl6 112 1044 0 1035 1 0 1 1 0 8 0 amappl5 104 2353 0 2341 1 0 1 1 0 8 0 amappl4 96 9656 0 9629 1 0 1 1 0 8 0 amappl3 88 2283 0 2271 1 0 1 1 0 8 0 amappl2 80 60462 0 60397 3 1 2 3 0 8 0 amappl1 72 266207 0 265761 23 13 10 19 0 8 0 amappl 80 28188 0 28152 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 64 155 0 26 3 0 3 3 0 8 0 uaddrrnd 24 9486 0 9470 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 9486 0 9470 1 0 1 1 0 8 0 vmmpekpl 168 79199 0 79175 3 1 2 2 0 8 0 vmmpepl 168 1212611 0 1211040 279 190 89 89 0 357 17 vmsppl 368 9485 0 9470 2 0 2 2 0 8 0 pdppl 4096 18980 0 18940 6 0 6 6 0 8 0 pvpl 32 2747710 0 2738151 452 342 110 122 0 265 15 pmappl 232 9485 0 9470 24 22 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 634 0 27 19 1 18 18 0 8 0