uvpanic: freeing message queue with active references Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 107939 72389 0 0 0x4000000 0 syz-executor *139465 93574 0 0 0x4000000 1K syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834b13ba) at panic+0x1e5 sys/kern/subr_prf.c:198 que_free(ffff80000160a000) at que_free+0x15c sys_msgctl(ffff8000fffe8fb0,ffff800037fb0380,ffff800037fb02d0) at sys_msgctl+0x4ae sys/kern/sysv_msg.c:129 syscall(ffff800037fb0380) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800037fb0380) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8ab12ff7bd0, 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 *cpu0: uvm_fault(0xfffffd806c709b88, 0x98, 0, 1) -> e cpu1: freeing message queue with active references ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834b13ba) at panic+0x1e5 sys/kern/subr_prf.c:198 que_free(ffff80000160a000) at que_free+0x15c sys_msgctl(ffff8000fffe8fb0,ffff800037fb0380,ffff800037fb02d0) at sys_msgctl+0x4ae sys/kern/sysv_msg.c:129 syscall(ffff800037fb0380) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800037fb0380) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8ab12ff7bd0, count: -6 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800037fb00b0 rbx 0xffff8000299aee07 rdx 0xffff8000015f1e40 rcx 0xffff8000fffe8fb0 rax 0xffff8000299adff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xbf497cdbe549363 r11 0xad07f515c1749392 r12 0xffff8000299aec08 r13 0 r14 0xffffffff8388fc08 cpu_info_full_primary+0x2c08 r15 0x1 rip 0xffffffff81473b35 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff800037fb00a0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=139465 pid=93574 tcnt=3 stat=onproc flags process=0 proc=4000000 runpri=50, usrpri=50, slppri=17, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000fffe9ca8,0xffffffff839b2398 process=0xffff8000fffe5360 user=0xffff800037fab000, vmspace=0xfffffd806c709d70 estcpu=8, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 72389 501263 49173 0 2 0 syz-executor 72389 107939 49173 0 7 0x4000000 syz-executor 58049 177728 70831 60929 2 0x10 syz-executor 58049 178039 70831 60929 3 0x4000090 fsleep syz-executor 93574 24395 77348 0 2 0 syz-executor 93574 378925 77348 0 2 0x4000080 syz-executor *93574 139465 77348 0 7 0x4000000 syz-executor 62675 439567 79851 0 3 0x80 nanoslp syz-executor 62675 428720 79851 0 3 0x4000080 fsleep syz-executor 62675 509441 79851 0 3 0x4000080 fsleep syz-executor 62675 162775 79851 0 3 0x4000080 lockf syz-executor 60674 76233 89542 0 3 0x81 nanoslp syz-executor 60674 250203 89542 0 3 0x4000081 ttyin syz-executor 60674 483978 89542 0 3 0x4000081 fsleep syz-executor 48327 125618 46980 0 3 0x80 nanoslp syz-executor 48327 113458 46980 0 3 0x4000080 sbwait syz-executor 48327 291208 46980 0 3 0x4000080 fsleep syz-executor 77348 356948 87199 0 3 0x82 nanoslp syz-executor 79851 360243 87199 0 3 0x82 nanoslp syz-executor 70831 297922 87199 0 3 0x82 nanoslp syz-executor 84418 239809 87199 0 3 0x2 biowait syz-executor 89542 198567 87199 0 3 0x82 nanoslp syz-executor 49173 367689 87199 0 3 0x82 nanoslp syz-executor 46980 391646 87199 0 3 0x82 nanoslp syz-executor 87532 101721 87199 0 3 0x82 nanoslp syz-executor 87199 100016 66970 0 3 0x82 kqread syz-executor 66970 446324 71695 0 3 0x10008a sigsusp ksh 71695 243315 74282 0 3 0x98 kqread sshd-session 74282 336408 10558 0 3 0x92 kqread sshd-session 43582 77455 1 0 3 0x100083 ttyin getty 10558 403204 1 0 3 0x88 kqread sshd 33032 174482 94088 74 3 0x1100092 bpf pflogd 94088 340571 1 0 3 0x80 sbwait pflogd 11433 255962 85401 73 3 0x1100090 kqread syslogd 85401 230099 1 0 3 0x100082 sbwait syslogd 10841 114723 1 0 3 0x100080 kqread resolvd 16443 258611 8431 77 3 0x100092 kqread dhcpleased 24985 218591 8431 77 3 0x100092 kqread dhcpleased 8431 101376 1 0 3 0x80 kqread dhcpleased 73964 64595 0 0 3 0x14200 pause smr 95246 398919 0 0 2 0x14200 zerothread 90025 197546 0 0 3 0x14200 aiodoned aiodoned 54599 23296 0 0 3 0x14200 syncer update 54000 479832 0 0 3 0x14200 cleaner cleaner 97873 202684 0 0 3 0x14200 reaper reaper 41594 130321 0 0 3 0x14200 pgdaemon pagedaemon 4225 282544 0 0 3 0x14200 bored viomb 76934 285679 0 0 3 0x40014200 acpi0 acpi0 53104 202604 0 0 3 0x40014200 idle1 78572 37900 0 0 3 0x14200 bored softnet1 27192 170443 0 0 3 0x14200 bored softnet0 84486 492121 0 0 3 0x14200 bored systqmp 19411 113535 0 0 3 0x14200 bored systq 25482 222916 0 0 3 0x14200 tmoslp softclockmp 81775 97262 0 0 3 0x40014200 tmoslp softclock 6891 345882 0 0 3 0x40014200 idle0 1 166195 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 72389 (syz-executor) thread 0xffff8000fffe9ca8 (107939) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a38200) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] #1 syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783 #2 Xsyscall+0x128 Process 84418 (syz-executor) thread 0xffff80002a231ca0 (239809) exclusive rrwlock inode r = 0 (0xfffffd806c67e560) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576 #5 vget+0x2a2 sys/kern/vfs_subr.c:686 #6 ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98 #7 ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1203 #8 ufs_lookup+0x1a36 sys/ufs/ufs/ufs_lookup.c:478 #9 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85 #10 vfs_lookup+0x98a sys/kern/vfs_lookup.c:567 #11 namei+0x7ca sys/kern/vfs_lookup.c:250 #12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1887 #13 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #13 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806d563680) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576 #5 vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1 #6 namei+0x7ca sys/kern/vfs_lookup.c:250 #7 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1887 #8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #9 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11061 12084K 12453K 166960K 12303 0 pcb 17 12K 12K 166960K 45 0 rtable 222 7K 8K 166960K 359 0 pf 32 17K 21K 166960K 58 0 ifaddr 39 6K 7K 166960K 52 0 ifgroup 51 2K 2K 166960K 70 0 sysctl 1 1K 9K 166960K 6 0 counters 68 36K 37K 166960K 84 0 ioctlops 0 0K 4K 166960K 1604 0 iov 0 0K 16K 166960K 9 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1330 84K 84K 166960K 1497 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 20K 24K 166960K 7 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 20 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 89K 166960K 256 0 proc 72 115K 180K 166960K 566 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 24 0 in_multi 88 6K 7K 166960K 103 0 ether_multi 1 0K 0K 166960K 2 0 mrt 0 0K 0K 166960K 8 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 61 281K 281K 166960K 61 0 exec 0 0K 1K 166960K 392 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 248 167K 175K 166960K 4122 0 UVM aobj 10 5K 5K 166960K 14 0 pinsyscall 42 84K 101K 166960K 1393 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 2 0 NDP 11 0K 2K 166960K 33 0 temp 37 9070K 9134K 166960K 9348 0 kqueue 13 20K 27K 166960K 49 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> 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 41 0 38 1 0 1 1 0 8 0 rtentry 176 112 0 12 6 0 6 6 0 8 0 unpcb 144 85 0 66 1 0 1 1 0 8 0 syncache 336 5 0 5 1 0 1 1 0 8 1 tcpcb 736 38 0 33 1 0 1 1 0 8 0 arp 136 18 0 2 1 0 1 1 0 8 0 inpcb 328 159 0 150 2 0 2 2 0 8 0 nd6 152 25 0 3 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1192 5 0 5 1 0 1 1 0 8 1 pffrag 232 2 0 0 1 0 1 1 0 482 0 pffrnode 88 2 0 0 1 0 1 1 0 8 0 pffrent 40 2 0 0 1 0 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfrktable 1344 1 0 0 1 0 1 1 0 8 0 pfstlim 224 1 0 1 1 0 1 1 0 8 1 pfstitem 24 24 0 1 1 0 1 1 0 8 0 pfstkey 128 24 0 1 1 0 1 1 0 8 0 pfstate 448 24 0 1 3 0 3 3 0 8 0 pfrule 1360 22 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 454 0 44 29 0 29 29 0 8 2 art_table 40 455 0 44 5 0 5 5 0 8 0 art_node 32 112 0 21 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 0 1 0 1 1 0 8 0 semupl 112 5 0 5 1 0 1 1 0 8 1 semapl 112 16 0 6 1 0 1 1 0 8 0 shmpl 112 11 0 4 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 1782 0 319 93 0 93 93 0 8 0 ffsino 296 1782 0 319 114 0 114 114 0 8 0 nchpl 144 2156 0 453 64 0 64 64 0 8 0 rtmask 32 2 0 2 1 0 1 1 0 8 1 vnodes 216 1961 0 0 109 0 109 109 0 8 0 namei 1024 7038 0 7038 1 0 1 1 0 8 1 percpumem 16 57 0 8 1 0 1 1 0 8 0 kstatmem 264 37 0 12 3 0 3 3 0 8 1 scxspl 216 7438 0 7437 9 1 8 8 1 8 7 plimitpl 152 33 0 15 1 0 1 1 0 8 0 sigapl 424 568 0 521 7 0 7 7 0 8 1 knotepl 120 298 0 0 10 0 10 10 0 8 0 kqueuepl 224 100 0 90 3 0 3 3 0 8 2 pipepl 344 131 0 103 3 0 3 3 0 8 0 fdescpl 528 552 0 521 3 0 3 3 0 8 0 filepl 160 2532 0 2264 13 0 13 13 0 8 1 lockfpl 104 131 0 122 1 0 1 1 0 8 0 lockfspl 48 23 0 18 1 0 1 1 0 8 0 sessionpl 144 91 0 81 1 0 1 1 0 8 0 pgrppl 48 99 0 81 1 0 1 1 0 8 0 ucredpl 104 225 0 211 1 0 1 1 0 8 0 zombiepl 144 522 0 521 1 0 1 1 0 8 0 processpl 1232 568 0 521 5 0 5 5 0 8 0 procpl 664 784 0 726 6 0 6 6 0 8 0 sosppl 176 1 0 1 1 0 1 1 0 8 1 sockpl 752 293 0 262 5 0 5 5 0 8 0 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 133 0 0 17 0 17 17 0 8 0 mcl2k 2048 18 0 0 3 0 3 3 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 131 0 0 9 0 9 9 0 8 0 bufpl 280 2561 0 105 176 0 176 176 0 8 0 anonpl 32 5546 0 0 45 0 45 45 0 246 0 amapchunkpl 152 12464 0 11952 27 0 27 27 0 158 5 amappl16 200 1728 0 1695 5 2 3 5 0 8 1 amappl15 192 6 0 6 1 1 0 1 0 8 0 amappl14 184 428 0 427 1 0 1 1 0 8 0 amappl13 176 117 0 105 1 0 1 1 0 8 0 amappl12 168 797 0 767 2 0 2 2 0 8 0 amappl11 160 1 0 1 1 1 0 1 0 8 0 amappl10 152 68 0 54 1 0 1 1 0 8 0 amappl9 144 263 0 263 1 1 0 1 0 8 0 amappl8 136 107 0 105 1 0 1 1 0 8 0 amappl7 128 147 0 134 1 0 1 1 0 8 0 amappl6 120 159 0 158 1 0 1 1 0 8 0 amappl5 112 95 0 84 1 0 1 1 0 8 0 amappl4 104 284 0 263 1 0 1 1 0 8 0 amappl3 96 2237 0 2120 4 0 4 4 0 8 0 amappl2 88 519 0 458 2 0 2 2 0 8 0 amappl1 80 9738 0 9133 15 0 15 15 0 8 2 amappl 88 3396 0 3222 5 0 5 5 0 92 0 uvmvnodes 80 104 0 0 3 0 3 3 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 28 0 28 2 1 1 1 0 8 1 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 13 0 4 1 0 1 1 0 8 0 uaddrrnd 24 552 0 521 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 552 0 521 1 0 1 1 0 8 0 vmmpekpl 168 6186 0 6149 3 0 3 3 0 8 0 vmmpepl 168 42169 0 40241 87 0 87 87 0 357 0 vmsppl 488 551 0 521 5 0 5 5 0 8 1 rwobjpl 80 14651 0 13590 24 0 24 24 0 8 2 pdppl 4096 1111 0 1042 95 22 73 83 0 8 4 pvpl 32 12639 0 0 102 0 102 102 0 265 0 pmappl 256 551 0 521 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 267 0 25 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff8388eff0) 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+0x39 sys/dev/kcov.c:159 intr_handler(ffff80003c3ff200,ffff8000002a3480) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:560 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __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(ffffffff83a37a00) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a37a00) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 cnputc(76) at cnputc+0x67 sys/dev/cons.c:218 db_putchar(76) at db_putchar+0x36d sys/ddb/db_output.c:155 kprintf() at kprintf+0x29c5 sys/kern/subr_prf.c:-1 end trace frame: 0xffff80003c3ff640, count: 0 ddb{0}> trace x86_ipi_db(ffffffff8388eff0) 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+0x39 sys/dev/kcov.c:159 intr_handler(ffff80003c3ff200,ffff8000002a3480) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:560 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __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(ffffffff83a37a00) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a37a00) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 cnputc(76) at cnputc+0x67 sys/dev/cons.c:218 db_putchar(76) at db_putchar+0x36d sys/ddb/db_output.c:155 kprintf() at kprintf+0x29c5 sys/kern/subr_prf.c:-1 db_printf(ffffffff833f72db) at db_printf+0x9b sys/kern/subr_prf.c:-1 fault(ffffffff834b1ea1) at fault+0xa7 sys/arch/amd64/amd64/trap.c:161 kpageflttrap(ffff80003c3ff7a0,98) at kpageflttrap+0x37d sys/arch/amd64/amd64/trap.c:296 kerntrap(ffff80003c3ff7a0) at kerntrap+0x19d sys/arch/amd64/amd64/trap.c:528 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dovutimens(ffff8000fffe9ca8,fffffd8060a966e0,ffff80003c3ff960) at dovutimens+0x368 sys/kern/vfs_syscalls.c:2771 sys_futimens(ffff8000fffe9ca8,ffff80003c3ffab0,ffff80003c3ffa00) at sys_futimens+0xb3 sys/kern/vfs_syscalls.c:2847 syscall(ffff80003c3ffab0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c3ffab0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7b0f5808e80, count: -23 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x25: addq $0x8,%rsp db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834b13ba) at panic+0x1e5 sys/kern/subr_prf.c:198 que_free(ffff80000160a000) at que_free+0x15c sys_msgctl(ffff8000fffe8fb0,ffff800037fb0380,ffff800037fb02d0) at sys_msgctl+0x4ae sys/kern/sysv_msg.c:129 syscall(ffff800037fb0380) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800037fb0380) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8ab12ff7bd0, count: 9 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834b13ba) at panic+0x1e5 sys/kern/subr_prf.c:198 que_free(ffff80000160a000) at que_free+0x15c sys_msgctl(ffff8000fffe8fb0,ffff800037fb0380,ffff800037fb02d0) at sys_msgctl+0x4ae sys/kern/sysv_msg.c:129 syscall(ffff800037fb0380) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800037fb0380) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8ab12ff7bd0, count: -6