login: panic: mutex 0xfffffd806e9aabd0 not held in knote_dequeue Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 200045 56994 32767 0x10 0 1 syz-executor.1 * 73016 71484 32767 0x10 0x4000000 0K syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic(ffffffff8246025e) at panic+0x177 sys/kern/subr_prf.c:202 knote_dequeue(fffffd806e8a8070) at knote_dequeue+0x12b sys/kern/kern_event.c:1860 filt_timermodify(ffff8000234b6c40,fffffd806e8a8070) at filt_timermodify+0x6f sys/kern/kern_event.c:479 kqueue_register(fffffd806e9aabd0,ffff8000234b6c40,ffff8000212a5260) at kqueue_register+0xa89 filter_modify sys/kern/kern_event.c:662 [inline] kqueue_register(fffffd806e9aabd0,ffff8000234b6c40,ffff8000212a5260) at kqueue_register+0xa89 sys/kern/kern_event.c:1125 sys_kevent(ffff8000212a5260,ffff8000234b6ef8,ffff8000234b6f40) at sys_kevent+0x214 sys/kern/kern_event.c:887 syscall(ffff8000234b6fc0) at syscall+0x5bf mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000234b6fc0) at syscall+0x5bf sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5e0afcddcf0, count: 7 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: mutex 0xfffffd806e9aabd0 not held in knote_dequeue ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic(ffffffff8246025e) at panic+0x177 sys/kern/subr_prf.c:202 knote_dequeue(fffffd806e8a8070) at knote_dequeue+0x12b sys/kern/kern_event.c:1860 filt_timermodify(ffff8000234b6c40,fffffd806e8a8070) at filt_timermodify+0x6f sys/kern/kern_event.c:479 kqueue_register(fffffd806e9aabd0,ffff8000234b6c40,ffff8000212a5260) at kqueue_register+0xa89 filter_modify sys/kern/kern_event.c:662 [inline] kqueue_register(fffffd806e9aabd0,ffff8000234b6c40,ffff8000212a5260) at kqueue_register+0xa89 sys/kern/kern_event.c:1125 sys_kevent(ffff8000212a5260,ffff8000234b6ef8,ffff8000234b6f40) at sys_kevent+0x214 sys/kern/kern_event.c:887 syscall(ffff8000234b6fc0) at syscall+0x5bf mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000234b6fc0) at syscall+0x5bf sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5e0afcddcf0, count: -8 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000234b6a30 rbx 0xffffffff8270abf7 cpu_info_full_primary+0x2bf7 rdx 0x8b rcx 0x2 rax 0x3a r8 0xffffffff81bb3f14 kprintf+0x144 r9 0x1 r10 0x34b6ba136b3a7642 r11 0x46499c3d09efc712 r12 0xffffffff8270a9f8 cpu_info_full_primary+0x29f8 r13 0 r14 0 r15 0x1 rip 0xffffffff81b43698 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000234b6a20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=73016 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=75, nice=20 forw=0xffffffffffffffff, list=0xffff8000212a5500,0xffff8000212a4fd0 process=0xffff80002127f6f0 user=0xffff8000234b2000, vmspace=0xfffffd807f009730 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 56994 200045 73422 32767 7 0x10 syz-executor.1 71484 509043 56350 32767 2 0x10 syz-executor.0 *71484 73016 56350 32767 7 0x4000010 syz-executor.0 71484 230447 56350 32767 3 0x4000090 fsleep syz-executor.0 73422 393157 83627 32767 3 0x90 nanoslp syz-executor.1 56350 442874 64113 32767 3 0x90 nanoslp syz-executor.0 83627 501653 44417 0 3 0x82 wait syz-executor.1 64113 186957 44417 0 3 0x82 wait syz-executor.0 44417 350264 21982 0 3 0x82 thrsleep syz-fuzzer 44417 282803 21982 0 3 0x4000082 thrsleep syz-fuzzer 44417 480166 21982 0 3 0x4000082 thrsleep syz-fuzzer 44417 382938 21982 0 3 0x4000082 thrsleep syz-fuzzer 44417 345804 21982 0 3 0x4000082 thrsleep syz-fuzzer 44417 514566 21982 0 3 0x4000082 thrsleep syz-fuzzer 44417 50058 21982 0 3 0x4000082 thrsleep syz-fuzzer 44417 332452 21982 0 3 0x4000082 kqread syz-fuzzer 21982 81687 66574 0 3 0x10008a sigsusp ksh 66574 83794 4730 0 3 0x92 select sshd 60898 219536 1 0 3 0x100083 ttyin getty 4730 331246 1 0 3 0x80 select sshd 16888 353627 43692 73 3 0x100090 kqread syslogd 43692 30380 1 0 3 0x100082 netio syslogd 95240 264142 1 77 3 0x100090 poll dhclient 41115 363743 1 0 3 0x80 poll dhclient 62906 157961 0 0 3 0x14200 bored smr 16567 476736 0 0 2 0x14200 zerothread 44344 470912 0 0 3 0x14200 aiodoned aiodoned 36098 424179 0 0 3 0x14200 syncer update 78283 208178 0 0 3 0x14200 cleaner cleaner 93204 209121 0 0 3 0x14200 reaper reaper 52133 148749 0 0 3 0x14200 pgdaemon pagedaemon 85783 5663 0 0 3 0x14200 bored crynlk 92514 279025 0 0 3 0x14200 bored crypto 50678 275949 0 0 3 0x14200 bored viomb 38553 22139 0 0 3 0x40014200 acpi0 acpi0 17560 235913 0 0 3 0x40014200 idle1 29897 117088 0 0 3 0x14200 bored softnet 98795 186189 0 0 3 0x14200 bored systqmp 32083 198894 0 0 3 0x14200 bored systq 11331 346019 0 0 3 0x40014200 bored softclock 53235 453618 0 0 3 0x40014200 idle0 1 92196 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 56994 (syz-executor.1) thread 0xffff8000212a4fc0 (200045) exclusive rwlock amaplk r = 0 (0xfffffd8069c3d518) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1182 #1 uvm_fault_check+0x3de sys/uvm/uvm_fault.c:774 #2 uvm_fault+0x102 sys/uvm/uvm_fault.c:601 #3 upageflttrap+0x82 sys/arch/amd64/amd64/trap.c:181 #4 usertrap+0x21a sys/arch/amd64/amd64/trap.c:403 #5 recall_trap+0x8 shared rwlock vmmaplk r = 0 (0xfffffd807f009a28) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1182 #1 uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1701 #2 uvm_fault_check+0x3a sys/uvm/uvm_fault.c:674 #3 uvm_fault+0x102 sys/uvm/uvm_fault.c:601 #4 upageflttrap+0x82 sys/arch/amd64/amd64/trap.c:181 #5 usertrap+0x21a sys/arch/amd64/amd64/trap.c:403 #6 recall_trap+0x8 Process 71484 (syz-executor.0) thread 0xffff8000212a5260 (73016) exclusive kernel_lock &kernel_lock r = 1 (0xffffffff8294f968) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1182 #1 syscall+0x439 mi_syscall sys/sys/syscall_mi.h:93 [inline] #1 syscall+0x439 sys/arch/amd64/amd64/trap.c:587 #2 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10114 6414K 6414K 78643K 11204 0 pcb 13 8K 8K 78643K 13 0 rtable 105 3K 3K 78643K 187 0 ifaddr 39 10K 10K 78643K 39 0 counters 44 34K 34K 78643K 44 0 ioctlops 0 0K 2K 78643K 432 0 iov 0 0K 2K 78643K 171 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 1 0 vnodes 1216 76K 76K 78643K 1221 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 3 5K 9K 78643K 105 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 375 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12598 0 file desc 8 25K 33K 78643K 12716 0 sigio 0 0K 0K 78643K 34 0 proc 48 50K 83K 78643K 355 0 subproc 34 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 33 2K 2K 78643K 33 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 31 148K 148K 78643K 31 0 exec 0 0K 2K 78643K 313 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 193 26K 26K 78643K 151771 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 5 0K 0K 78643K 9 0 temp 101 3985K 4049K 78643K 27528 0 kqueue 5 5K 9K 78643K 537 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 17 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 6811 0 6803 1 0 1 1 0 8 0 syncache 296 4 0 4 1 1 0 1 0 8 0 tcpcb 736 1105 0 1101 5 4 1 5 0 8 0 arp 120 6 0 0 1 0 1 1 0 8 0 ipq 40 2 0 2 1 1 0 1 0 8 0 ipqe 40 43 0 43 1 1 0 1 0 8 0 inpcb 304 1338 0 1332 1 0 1 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 kcovpl 48 2 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 187 0 0 12 0 12 12 0 8 0 art_table 32 188 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 semapl 112 373 0 363 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 14232 0 12834 88 0 88 88 0 8 0 ffsino 272 14232 0 12834 94 0 94 94 0 8 0 nchpl 144 30604 0 28995 60 0 60 60 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 224 5926 0 0 349 0 349 349 0 8 0 namei 1024 71283 0 71283 1 0 1 1 0 8 1 percpumem 16 34 0 0 1 0 1 1 0 8 0 scxspl 216 83616 0 83616 9 8 1 8 0 8 1 plimitpl 152 16 0 7 1 0 1 1 0 8 0 sigapl 424 12903 0 12870 4 0 4 4 0 8 0 futexpl 56 55044 0 55043 2 1 1 1 0 8 0 knotepl 112 38 0 0 2 0 2 2 0 8 0 kqueuepl 216 2180 0 2176 1 0 1 1 0 8 0 pipepl 336 1672 0 1661 10 8 2 2 0 8 1 fdescpl 496 12887 0 12870 3 0 3 3 0 8 0 filepl 152 39734 0 39634 12 7 5 5 0 8 1 lockfpl 104 315 0 314 1 0 1 1 0 8 0 lockfspl 48 140 0 139 1 0 1 1 0 8 0 sessionpl 144 17 0 7 1 0 1 1 0 8 0 pgrppl 48 17 0 7 1 0 1 1 0 8 0 ucredpl 96 741 0 732 1 0 1 1 0 8 0 zombiepl 144 12870 0 12870 1 0 1 1 0 8 1 processpl 1080 12903 0 12870 4 1 3 3 0 8 0 procpl 672 27600 0 27558 4 0 4 4 0 8 0 sockpl 480 8378 0 8362 8 5 3 4 0 8 0 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 19 0 0 3 0 3 3 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 20 0 0 3 0 3 3 0 8 0 mcl2k2 2112 17 0 0 2 0 2 2 0 8 0 mcl2k 2048 116 0 0 12 0 12 12 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 462 0 0 15 0 15 15 0 8 0 bufpl 280 16081 0 9764 452 0 452 452 0 8 0 anonpl 24 3220582 0 3214979 50 9 41 41 0 186 4 amapchunkpl 152 358961 0 358585 22 7 15 16 0 158 0 amappl16 200 23944 0 23807 12 1 11 11 0 8 3 amappl15 192 56 0 49 1 0 1 1 0 8 0 amappl14 184 2 0 2 1 1 0 1 0 8 0 amappl13 176 6263 0 6259 1 0 1 1 0 8 0 amappl12 168 12 0 10 1 0 1 1 0 8 0 amappl11 160 37 0 28 1 0 1 1 0 8 0 amappl10 152 6492 0 6483 1 0 1 1 0 8 0 amappl9 144 228 0 228 2 2 0 1 0 8 0 amappl8 136 443 0 382 3 0 3 3 0 8 0 amappl7 128 58 0 51 1 0 1 1 0 8 0 amappl6 120 98 0 85 1 0 1 1 0 8 0 amappl5 112 19506 0 19493 1 0 1 1 0 8 0 amappl4 104 721 0 693 1 0 1 1 0 8 0 amappl3 96 718 0 710 1 0 1 1 0 8 0 amappl2 88 19704 0 19656 2 0 2 2 0 8 0 amappl1 80 199031 0 198614 12 3 9 12 0 8 0 amappl 88 151507 0 151385 3 0 3 3 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 64 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 12887 0 12870 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 12887 0 12870 1 0 1 1 0 8 0 vmmpekpl 168 58588 0 58566 2 0 2 2 0 8 0 vmmpepl 168 1441293 0 1439737 75 3 72 72 0 357 3 vmsppl 368 12886 0 12870 2 0 2 2 0 8 0 rwobjpl 56 240408 0 239620 19 6 13 13 0 8 1 pdppl 4096 25781 0 25740 55 14 41 45 0 8 0 pvpl 32 5442818 0 5433849 176 90 86 130 0 265 11 pmappl 232 12886 0 12870 2 1 1 2 0 8 0 extentpl 40 58 0 40 1 0 1 1 0 8 0 phpool 112 313 0 28 9 0 9 9 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:399 panic(ffffffff8246025e) at panic+0x177 sys/kern/subr_prf.c:202 knote_dequeue(fffffd806e8a8070) at knote_dequeue+0x12b sys/kern/kern_event.c:1860 filt_timermodify(ffff8000234b6c40,fffffd806e8a8070) at filt_timermodify+0x6f sys/kern/kern_event.c:479 kqueue_register(fffffd806e9aabd0,ffff8000234b6c40,ffff8000212a5260) at kqueue_register+0xa89 filter_modify sys/kern/kern_event.c:662 [inline] kqueue_register(fffffd806e9aabd0,ffff8000234b6c40,ffff8000212a5260) at kqueue_register+0xa89 sys/kern/kern_event.c:1125 sys_kevent(ffff8000212a5260,ffff8000234b6ef8,ffff8000234b6f40) at sys_kevent+0x214 sys/kern/kern_event.c:887 syscall(ffff8000234b6fc0) at syscall+0x5bf mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000234b6fc0) at syscall+0x5bf sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5e0afcddcf0, count: -8 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:353 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(ffffffff8294f760) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff8294f760) at __mp_lock+0x122 sys/kern/kern_lock.c:147 uvm_fault(fffffd807f009a10,c4193c6a000,0,2) at uvm_fault+0x23a sys/uvm/uvm_fault.c:637 upageflttrap(ffff8000256d37a0,c4193c6a6f2) at upageflttrap+0x82 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff8000256d37a0) at usertrap+0x21a sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7ffffbc4a0, count: 7 ddb{1}> trace x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:353 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(ffffffff8294f760) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff8294f760) at __mp_lock+0x122 sys/kern/kern_lock.c:147 uvm_fault(fffffd807f009a10,c4193c6a000,0,2) at uvm_fault+0x23a sys/uvm/uvm_fault.c:637 upageflttrap(ffff8000256d37a0,c4193c6a6f2) at upageflttrap+0x82 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff8000256d37a0) at usertrap+0x21a sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7ffffbc4a0, count: -8