witness: lock order reversal: 1st 0xffff8000fffea070 fdlock (&newfdp->fd_fd.fd_lock) 2nd 0xfffffd806e106590 inode (&ip->i_lock) lock order [1] fdlock (&newfdp->fd_fd.fd_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff8337242b -> 0xffffffff833676f0 is missing lock order [2] inode (&ip->i_lock) -> [3] sbufrcv (&so->so_rcv.sb_lock) #0 rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 #1 sblock+0xb6 sys/kern/uipc_socket2.c:536 #2 soreceive+0x27d sys/kern/uipc_socket.c:878 #3 fifo_read+0x117 sys/miscfs/fifofs/fifo_vnops.c:264 #4 VOP_READ+0x101 sys/kern/vfs_vops.c:227 #5 vn_rdwr+0x15b sys/kern/vfs_vnops.c:-1 #6 vndsetcred+0xa1 sys/dev/vnd.c:685 #7 vndioctl+0xdfb sys/dev/vnd.c:486 #8 VOP_IOCTL+0xac sys/kern/vfs_vops.c:264 #9 vn_ioctl+0xf8 sys/kern/vfs_vnops.c:531 #10 sys_ioctl+0x674 sys/kern/sys_generic.c:-1 #11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #12 Xsyscall+0x128 lock order [3] sbufrcv (&so->so_rcv.sb_lock) -> [1] fdlock (&newfdp->fd_fd.fd_lock) #0 rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 #1 unp_externalize+0x3cf sys/kern/uipc_usrreq.c:1074 #2 soreceive+0xc24 sys/kern/uipc_socket.c:1017 #3 recvit+0x40b sys/kern/uipc_syscalls.c:1078 #4 sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:878 #5 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #6 Xsyscall+0x128 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic the kernel did not panic ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(fffffd806e106590,9,0) at witness_checkorder+0x10b9 sys/kern/subr_witness.c:-1 rw_do_enter_write(fffffd806e106578,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 rrw_enter(fffffd806e106578,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 VOP_LOCK(fffffd806e109990,2001) at VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 vn_lock(fffffd806e109990,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vn_closefile(fffffd80602db0f0,ffff80002a2914d8) at vn_closefile+0x111 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd80602db0f0,ffff80002a2914d8) at vn_closefile+0x111 sys/kern/vfs_vnops.c:615 fdrop(fffffd80602db0f0,ffff80002a2914d8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 knote_drop(fffffd806bb58ea0,ffff80002a2914d8) at knote_drop+0x1a1 sys/kern/kern_event.c:2296 knote_remove(ffff80002a2914d8,fffffd806ee592a0,fffffd806ee59330,3,0) at knote_remove+0x2f6 sys/kern/kern_event.c:2180 knote_fdclose(ffff80002a2914d8,3) at knote_fdclose+0xf9 sys/kern/kern_event.c:2203 fdrelease(ffff80002a2914d8,3) at fdrelease+0xf9 sys/kern/kern_descrip.c:760 syscall(ffff80003c422910) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c422910) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x65e3d5bfc10, count: -14 ddb{0}> show registers rdi 0 rsi 0x80000 acpi_pdirpa+0x6be71 rbp 0xffff80003c4223e0 rbx 0 rdx 0xffff80000144d880 rcx 0xffff80002a2914d8 rax 0x7ffff acpi_pdirpa+0x6be70 r8 0xffff80003c4222c0 r9 0x8080808080808080 r10 0x280732522eee96bf r11 0xf97b72f419eaf4dd r12 0xfffffd8003f27d00 r13 0xfffffd8004714bd0 r14 0x3 r15 0xffffffff834049f1 substchar+0xa39c rip 0xffffffff81027c95 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003c4223d0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=248556 pid=77603 tcnt=3 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000fffe9248,0xffff80002a290028 process=0xffff8000fffe4e90 user=0xffff80003c41d000, vmspace=0xfffffd806c00f3f0 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 41457 425053 33467 0 7 0 syz-executor 41457 326281 33467 0 3 0x4000080 fsleep syz-executor 15799 487181 67451 0 3 0x80 nanoslp syz-executor 15799 206703 67451 0 3 0x4000080 ttyin syz-executor 15799 221005 67451 0 3 0x4000080 fsleep syz-executor 15799 476563 67451 0 3 0x4000080 fsleep syz-executor 77603 169766 82150 0 2 0 syz-executor *77603 248556 82150 0 7 0x4000000 syz-executor 77603 52944 82150 0 3 0x4000080 fsleep syz-executor 26384 282953 46128 0 3 0x80 nanoslp syz-executor 26384 255660 46128 0 3 0x4000080 fsleep syz-executor 26384 174170 46128 0 3 0x4000080 fsleep syz-executor 32218 27752 8154 0 3 0x80 nanoslp syz-executor 32218 254179 8154 0 3 0x4000080 kqsel syz-executor 32218 13631 8154 0 3 0x4000080 fsleep syz-executor 36934 177255 0 0 3 0x14200 acct acct 11854 358958 1 0 3 0x100083 ttyin getty 36793 25442 92495 0 3 0x100082 sbwait arp 92495 170579 54168 0 3 0x10008a sigsusp sh 46128 352347 76781 0 3 0x82 nanoslp syz-executor 33467 299853 76781 0 3 0x82 nanoslp syz-executor 30040 419947 76781 0 3 0x82 nanoslp syz-executor 29544 279436 76781 0 3 0x82 nanoslp syz-executor 82150 365775 76781 0 3 0x82 nanoslp syz-executor 8154 7841 76781 0 3 0x82 nanoslp syz-executor 67451 499644 76781 0 3 0x82 nanoslp syz-executor 54168 348074 76781 0 3 0x82 wait syz-executor 76781 33507 3634 0 3 0x82 kqread syz-executor 3634 473368 3514 0 3 0x10008a sigsusp ksh 3514 484372 76153 0 3 0x98 kqread sshd-session 76153 22884 36232 0 3 0x92 kqread sshd-session 36232 192452 1 0 3 0x88 kqread sshd 65434 484375 25309 74 3 0x1100092 bpf pflogd 25309 131514 1 0 3 0x80 sbwait pflogd 4081 408894 33914 73 3 0x1100090 kqread syslogd 33914 81568 1 0 3 0x100082 sbwait syslogd 38067 386150 1 0 3 0x100080 kqread resolvd 36414 370593 26941 77 3 0x100092 kqread dhcpleased 61528 229175 26941 77 3 0x100092 kqread dhcpleased 26941 84882 1 0 3 0x80 kqread dhcpleased 40027 168108 0 0 3 0x14200 bored smr 93756 106072 0 0 3 0x14200 pgzero zerothread 8580 240824 0 0 3 0x14200 aiodoned aiodoned 29118 224161 0 0 3 0x14200 syncer update 36519 20300 0 0 3 0x14200 cleaner cleaner 52204 476910 0 0 3 0x14200 reaper reaper 24755 446760 0 0 3 0x14200 pgdaemon pagedaemon 77471 150615 0 0 3 0x14200 bored viomb 77069 161617 0 0 3 0x40014200 acpi0 acpi0 2698 294804 0 0 3 0x40014200 idle1 12794 153424 0 0 3 0x14200 bored softnet1 55112 448474 0 0 3 0x14200 bored softnet0 88073 380448 0 0 3 0x14200 smrbar systqmp 95034 248374 0 0 3 0x14200 bored systq 69598 170576 0 0 3 0x14200 tmoslp softclockmp 60618 29713 0 0 3 0x40014200 tmoslp softclock 97623 86126 0 0 3 0x40014200 idle0 1 305282 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 41457 (syz-executor) thread 0xffff8000fffe9778 (425053) exclusive rwlock uobjlk r = 0 (0xfffffd806c1e8080) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 uvm_fault+0x1e5 sys/uvm/uvm_fault.c:655 #3 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #4 usertrap+0x42f sys/arch/amd64/amd64/trap.c:622 #5 recall_trap+0x8 shared rwlock vmmaplk r = 0 (0xfffffd806c00f120) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_read+0x3e8 sys/kern/kern_rwlock.c:413 #2 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1902 #3 uvm_fault_check+0x4f sys/uvm/uvm_fault.c:699 #4 uvm_fault+0x106 sys/uvm/uvm_fault.c:633 #5 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #6 usertrap+0x42f sys/arch/amd64/amd64/trap.c:622 #7 recall_trap+0x8 Process 77603 (syz-executor) thread 0xffff80002a2914d8 (248556) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8389d228) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 vn_closefile+0x41 sys/kern/vfs_vnops.c:608 #2 fdrop+0x121 sys/kern/kern_descrip.c:1280 #3 knote_drop+0x1a1 sys/kern/kern_event.c:2296 #4 knote_remove+0x2f6 sys/kern/kern_event.c:2180 #5 knote_fdclose+0xf9 sys/kern/kern_event.c:2203 #6 fdrelease+0xf9 sys/kern/kern_descrip.c:760 #7 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #7 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #8 Xsyscall+0x128 exclusive rwlock fdlock r = 0 (0xffff8000fffea070) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 sys_close+0xd0 sys/kern/kern_descrip.c:778 #3 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #3 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #4 Xsyscall+0x128 Process 88073 (systqmp) thread 0xffff8000ffffe7c8 (380448) shared rwlock systqmp r = 0 (0xffffffff838448b8) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 taskq_thread+0x12a sys/kern/kern_task.c:442 #2 proc_trampoline+0x10 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10209 11090K 11239K 166960K 11773 0 pcb 17 12K 12K 166960K 104 0 rtable 162 6K 8K 166960K 389 0 pf 34 17K 19K 166960K 100 0 ifaddr 33 5K 7K 166960K 73 0 ifgroup 51 2K 2K 166960K 124 0 sysctl 3 1K 9K 166960K 11 0 counters 66 36K 38K 166960K 140 0 ioctlops 0 0K 5K 166960K 1548 0 iov 0 0K 16K 166960K 24 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1363 86K 86K 166960K 1706 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 10 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 19 0 dirhash 12 2K 2K 166960K 18 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 19 69K 89K 166960K 553 0 sigio 2 0K 0K 166960K 7 0 proc 72 115K 180K 166960K 584 0 subproc 72 4K 4K 166960K 72 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 144 0 in_multi 53 4K 6K 166960K 102 0 ether_multi 1 0K 0K 166960K 5 0 mrt 0 0K 0K 166960K 2 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 109 493K 493K 166960K 109 0 exec 0 0K 1K 166960K 416 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 266 170K 182K 166960K 6965 0 UVM aobj 11 2K 2K 166960K 11 0 pinsyscall 45 90K 105K 166960K 1675 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 23 0 NDP 11 0K 1K 166960K 46 0 temp 55 8654K 8720K 166960K 22529 0 kqueue 16 24K 28K 166960K 123 0 SYN cache 2 16K 16K 166960K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 26 0 0 1 0 1 1 0 8 0 rtpcb 120 71 0 67 1 0 1 1 0 8 0 rtentry 176 113 0 49 5 0 5 5 0 8 0 unpcb 144 302 0 283 4 0 4 4 0 8 3 syncache 336 6 0 6 1 0 1 1 0 8 1 tcpqe 32 2 0 2 2 1 1 1 0 8 1 tcpcb 736 199 0 191 7 0 7 7 0 8 6 arp 136 17 0 6 1 0 1 1 0 8 0 inpcb 328 555 0 543 9 2 7 7 0 8 5 nd6 152 21 0 9 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1192 26 0 26 1 0 1 1 0 8 1 pppxif 1504 7 0 7 1 0 1 1 0 8 1 pfstscr 40 4 0 4 2 1 1 1 0 8 1 pffrag 232 39 0 34 1 0 1 1 0 482 0 pffrnode 88 38 0 33 1 0 1 1 0 8 0 pffrent 40 73 0 68 1 0 1 1 0 8 0 pfosfp 40 1429 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1429 0 714 21 0 21 21 0 8 0 pfrktable 1344 1 0 1 1 0 1 1 0 8 1 pftag 88 2 0 0 1 0 1 1 0 8 0 pfstitem 24 63 0 1 1 0 1 1 0 8 0 pfstkey 128 68 0 6 2 0 2 2 0 8 0 pfstate 384 65 0 4 7 0 7 7 0 8 0 pfrule 1344 22 0 17 2 1 1 2 0 8 0 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 436 0 147 27 2 25 27 0 8 3 art_table 40 439 0 147 5 0 5 5 0 8 0 art_node 32 113 0 37 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 3 1 0 1 1 0 8 0 semapl 112 14 0 4 1 0 1 1 0 8 0 shmpl 112 8 0 0 1 0 1 1 0 8 0 dirhash 1024 21 0 4 3 0 3 3 0 8 0 dino2pl 256 2374 0 869 95 0 95 95 0 8 0 ffsino 296 2374 0 869 117 0 117 117 0 8 0 nchpl 144 3181 0 1477 64 0 64 64 0 8 0 rtmask 32 6 0 6 1 1 0 1 0 8 0 vnodes 216 2648 0 0 148 0 148 148 0 8 0 namei 1024 10132 0 10132 1 0 1 1 0 8 1 percpumem 16 85 0 37 1 0 1 1 0 8 0 kstatmem 264 68 0 42 3 0 3 3 0 8 1 scsiplug 72 1 0 1 1 1 0 1 0 8 0 scxspl 216 15183 0 15183 9 6 3 8 1 8 3 plimitpl 152 150 0 133 1 0 1 1 0 8 0 sigapl 424 864 0 814 7 1 6 7 0 8 0 knotepl 120 555 0 0 17 0 17 17 0 8 0 kqueuepl 224 184 0 170 2 1 1 2 0 8 0 pipepl 344 142 0 114 3 0 3 3 0 8 0 fdescpl 528 847 0 814 3 0 3 3 0 8 0 filepl 160 4384 0 4151 12 0 12 12 0 8 2 lockfpl 104 200 0 197 1 0 1 1 0 8 0 lockfspl 48 88 0 85 1 0 1 1 0 8 0 sessionpl 144 23 0 14 1 0 1 1 0 8 0 pgrppl 48 49 0 32 1 0 1 1 0 8 0 ucredpl 104 561 0 548 1 0 1 1 0 8 0 zombiepl 144 816 0 814 1 0 1 1 0 8 0 processpl 1232 864 0 814 5 0 5 5 0 8 0 procpl 664 1613 0 1553 6 0 6 6 0 8 0 sosppl 176 6 0 6 2 1 1 1 0 8 1 sockpl 752 938 0 903 11 1 10 10 0 8 5 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 118 0 0 15 0 15 15 0 8 0 mcl2k 2048 33 0 0 5 0 5 5 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 1771 0 0 111 0 111 111 0 8 0 bufpl 280 6731 0 594 439 0 439 439 0 8 0 anonpl 32 9242 0 0 75 0 75 75 0 246 0 amapchunkpl 152 22318 0 21782 28 1 27 27 0 158 6 amappl16 200 3466 0 3434 25 12 13 20 0 8 8 amappl14 184 6 0 6 1 1 0 1 0 8 0 amappl13 176 445 0 443 1 0 1 1 0 8 0 amappl12 168 1205 0 1160 3 0 3 3 0 8 0 amappl11 160 3 0 3 1 1 0 1 0 8 0 amappl10 152 64 0 50 1 0 1 1 0 8 0 amappl9 144 269 0 269 1 1 0 1 0 8 0 amappl8 136 28 0 26 1 0 1 1 0 8 0 amappl7 128 76 0 75 1 0 1 1 0 8 0 amappl6 120 276 0 260 1 0 1 1 0 8 0 amappl5 112 80 0 69 1 0 1 1 0 8 0 amappl4 104 419 0 389 1 0 1 1 0 8 0 amappl3 96 3757 0 3655 4 1 3 3 0 8 0 amappl2 88 956 0 879 2 0 2 2 0 8 0 amappl1 80 10720 0 10102 14 0 14 14 0 8 0 amappl 88 6171 0 5989 5 0 5 5 0 92 0 uvmvnodes 80 2648 0 0 55 0 55 55 0 8 0 dma65536 65536 1 0 1 1 1 0 1 0 8 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 72 10 0 0 1 0 1 1 0 8 0 uaddrrnd 24 848 0 815 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 848 0 815 1 0 1 1 0 8 0 vmmpekpl 168 8429 0 8395 2 0 2 2 0 8 0 vmmpepl 168 60739 0 58723 103 1 102 103 0 357 14 vmsppl 488 847 0 815 5 0 5 5 0 8 0 rwobjpl 80 21880 0 18239 76 0 76 76 0 8 0 pdppl 4096 1704 0 1630 96 22 74 84 0 8 0 pvpl 32 17665 0 0 143 0 143 143 0 265 0 pmappl 256 847 0 815 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 374 0 27 10 0 10 10 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(fffffd806e106590,9,0) at witness_checkorder+0x10b9 sys/kern/subr_witness.c:-1 rw_do_enter_write(fffffd806e106578,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 rrw_enter(fffffd806e106578,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 VOP_LOCK(fffffd806e109990,2001) at VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 vn_lock(fffffd806e109990,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vn_closefile(fffffd80602db0f0,ffff80002a2914d8) at vn_closefile+0x111 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd80602db0f0,ffff80002a2914d8) at vn_closefile+0x111 sys/kern/vfs_vnops.c:615 fdrop(fffffd80602db0f0,ffff80002a2914d8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 knote_drop(fffffd806bb58ea0,ffff80002a2914d8) at knote_drop+0x1a1 sys/kern/kern_event.c:2296 knote_remove(ffff80002a2914d8,fffffd806ee592a0,fffffd806ee59330,3,0) at knote_remove+0x2f6 sys/kern/kern_event.c:2180 knote_fdclose(ffff80002a2914d8,3) at knote_fdclose+0xf9 sys/kern/kern_event.c:2203 fdrelease(ffff80002a2914d8,3) at fdrelease+0xf9 sys/kern/kern_descrip.c:760 syscall(ffff80003c422910) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c422910) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x65e3d5bfc10, count: -14 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff8000299edff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c sys/dev/kcov.c:153 __mp_lock(ffffffff8389d020) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff8389d020) at __mp_lock+0x1a3 sys/kern/kern_lock.c:165 uvm_fault(fffffd806c00f020,6e124642000,0,1) at uvm_fault+0x1ea sys/uvm/uvm_fault.c:656 upageflttrap(ffff80003c45daa0,6e124642000) at upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 usertrap(ffff80003c45daa0) at usertrap+0x42f sys/arch/amd64/amd64/trap.c:622 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x763f943856f0, count: -9