login: panic: mutex 0xfffffd806e997a20 not held in knote_dequeue Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *268781 57485 0 0 0x4000000 1K syz-executor9499 157925 29810 0 0 0x4000000 0 syz-executor9499 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(fffffd806e89d1c0) at knote_dequeue+0x12b sys/kern/kern_event.c:1860 filt_timermodify(ffff800021258310,fffffd806e89d1c0) at filt_timermodify+0x6f sys/kern/kern_event.c:479 kqueue_register(fffffd806e997a20,ffff800021258310,ffff8000211b2008) at kqueue_register+0xa89 filter_modify sys/kern/kern_event.c:662 [inline] kqueue_register(fffffd806e997a20,ffff800021258310,ffff8000211b2008) at kqueue_register+0xa89 sys/kern/kern_event.c:1125 sys_kevent(ffff8000211b2008,ffff8000212585a8,ffff8000212585f0) at sys_kevent+0x214 sys/kern/kern_event.c:887 syscall(ffff800021258670) at syscall+0x5bf mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021258670) at syscall+0x5bf sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x21341784790, 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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: mutex 0xfffffd806e997a20 not held in knote_dequeue ddb{1}> 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(fffffd806e89d1c0) at knote_dequeue+0x12b sys/kern/kern_event.c:1860 filt_timermodify(ffff800021258310,fffffd806e89d1c0) at filt_timermodify+0x6f sys/kern/kern_event.c:479 kqueue_register(fffffd806e997a20,ffff800021258310,ffff8000211b2008) at kqueue_register+0xa89 filter_modify sys/kern/kern_event.c:662 [inline] kqueue_register(fffffd806e997a20,ffff800021258310,ffff8000211b2008) at kqueue_register+0xa89 sys/kern/kern_event.c:1125 sys_kevent(ffff8000211b2008,ffff8000212585a8,ffff8000212585f0) at sys_kevent+0x214 sys/kern/kern_event.c:887 syscall(ffff800021258670) at syscall+0x5bf mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021258670) at syscall+0x5bf sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x21341784790, count: -8 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff8000212580e0 rbx 0xffff800020d59bf7 rdx 0x8b rcx 0x2 rax 0x3a r8 0xffffffff81bb3f14 kprintf+0x144 r9 0x1 r10 0xabb57340811bfb93 r11 0xcfc86882c5cf7c70 r12 0xffff800020d599f8 r13 0 r14 0 r15 0x1 rip 0xffffffff81b43698 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000212580d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor9499) pid=268781 stat=onproc flags process=0 proc=4000000 pri=65, usrpri=65, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff6fd0,0xffff8000211b2a98 process=0xffff8000ffff3b28 user=0xffff800021253000, vmspace=0xfffffd806e9e0738 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 57485 19719 88605 0 3 0x80 nanoslp syz-executor9499 *57485 268781 88605 0 7 0x4000000 syz-executor9499 57485 352812 88605 0 2 0x4000000 syz-executor9499 57485 155039 88605 0 3 0x4000080 fsleep syz-executor9499 29810 172132 56941 0 2 0 syz-executor9499 29810 157925 56941 0 7 0x4000000 syz-executor9499 29810 93434 56941 0 3 0x4000080 fsleep syz-executor9499 88605 428568 40307 0 3 0x80 nanoslp syz-executor9499 56941 353292 40307 0 3 0x80 nanoslp syz-executor9499 40307 462644 13500 0 3 0x82 nanoslp syz-executor9499 13500 415989 64279 0 3 0x10008a sigsusp ksh 64279 346120 78589 0 3 0x92 select sshd 91301 378746 1 0 3 0x100083 ttyin getty 78589 203304 1 0 3 0x80 select sshd 58918 449291 62222 73 3 0x100090 kqread syslogd 62222 192181 1 0 3 0x100082 netio syslogd 20555 89564 1 77 3 0x100090 poll dhclient 96325 142872 1 0 3 0x80 poll dhclient 34975 378940 0 0 3 0x14200 bored smr 48676 381652 0 0 2 0x14200 zerothread 89504 360236 0 0 3 0x14200 aiodoned aiodoned 5100 507428 0 0 3 0x14200 syncer update 74563 131489 0 0 3 0x14200 cleaner cleaner 56845 121819 0 0 3 0x14200 reaper reaper 76479 470326 0 0 3 0x14200 pgdaemon pagedaemon 67431 282280 0 0 3 0x14200 bored crynlk 13852 492456 0 0 3 0x14200 bored crypto 88453 423784 0 0 3 0x14200 bored viomb 83642 442629 0 0 3 0x40014200 acpi0 acpi0 21810 211380 0 0 3 0x40014200 idle1 33119 179573 0 0 3 0x14200 bored softnet 23116 317794 0 0 3 0x14200 bored systqmp 47643 298169 0 0 3 0x14200 bored systq 72253 185856 0 0 3 0x40014200 bored softclock 19998 297588 0 0 3 0x40014200 idle0 1 172822 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 57485 (syz-executor9499) thread 0xffff8000211b2008 (268781) 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 Process 29810 (syz-executor9499) thread 0xffff8000ffff6fd0 (157925) exclusive rwlock amaplk r = 0 (0xfffffd806d9b0830) #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 (0xfffffd806e9e0470) #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 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10106 6409K 6410K 78643K 11196 0 pcb 13 8K 8K 78643K 13 0 rtable 61 2K 2K 78643K 111 0 ifaddr 24 7K 7K 78643K 24 0 counters 40 33K 33K 78643K 40 0 ioctlops 0 0K 2K 78643K 13 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 1 0 vnodes 1182 74K 74K 78643K 1187 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 12598 0 file desc 1 0K 0K 78643K 1 0 proc 47 50K 58K 78643K 274 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 11 0K 0K 78643K 11 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 19 95K 95K 78643K 19 0 exec 0 0K 2K 78643K 257 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 87 3K 4K 78643K 10142 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 3 0K 0K 78643K 3 0 temp 18 3973K 4037K 78643K 1431 0 kqueue 4 3K 5K 78643K 2296 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}>