witness: lock order reversal: 1st 0xffff800010fdc8a8 sbufrcv (&so->so_rcv.sb_lock) 2nd 0xfffffd8076fedc48 inode (&ip->i_lock) lock order [1] sbufrcv (&so->so_rcv.sb_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff830d7bd6 -> 0xffffffff8304eaf9 is missing lock order [2] inode (&ip->i_lock) -> [1] sbufrcv (&so->so_rcv.sb_lock) #0 rw_enter+0x122 #1 sblock+0xb7 sys/kern/uipc_socket2.c:549 #2 soreceive+0x298 sys/kern/uipc_socket.c:877 #3 fifo_read+0x11a sys/miscfs/fifofs/fifo_vnops.c:264 #4 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #5 vn_rdwr+0x15b #6 vndsetcred+0xa1 sys/dev/vnd.c:684 #7 vndioctl+0xe6c sys/dev/vnd.c:485 #8 VOP_IOCTL+0xac sys/kern/vfs_vops.c:264 #9 vn_ioctl+0xf6 sys/kern/vfs_vnops.c:525 #10 sys_ioctl+0x67c #11 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #11 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #12 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:437 witness_checkorder(fffffd8076fedc48,9,0) at witness_checkorder+0x1024 rw_enter(fffffd8076fedc38,1) at rw_enter+0x122 rrw_enter(fffffd8076fedc38,1) at rrw_enter+0xbe sys/kern/kern_rwlock.c:464 VOP_LOCK(fffffd8057f20980,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd8057f20980,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:564 vfs_getcwd_common(fffffd8057f20980,fffffd8057f202c0,0,0,200,0,cd0c88eace848f19) at vfs_getcwd_common+0xd1 sys/kern/vfs_getcwd.c:287 vn_isunder(fffffd8057f20980,fffffd8057f202c0,ffff8000ffff5478) at vn_isunder+0x56 sys/kern/vfs_vnops.c:688 unp_externalize(fffffd806cb10a00,101,0) at unp_externalize+0x286 sys/kern/uipc_usrreq.c:1088 soreceive(ffff800010fdc7d8,ffff800030b8caa8,ffff800030b8ca58,0,ffff800030b8ca98,ffff800030b8cc1c,f5acfaa2eb5ae0d2) at soreceive+0xd3e sys/kern/uipc_socket.c:1022 recvit(ffff8000ffff5478,8,ffff800030b8cbf0,0,ffff800030b8cbe0) at recvit+0x40a sys/kern/uipc_syscalls.c:1082 sys_recvmmsg(ffff8000ffff5478,ffff800030b8cdb0,ffff800030b8cd00) at sys_recvmmsg+0x3d3 sys/kern/uipc_syscalls.c:973 syscall(ffff800030b8cdb0) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] syscall(ffff800030b8cdb0) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe6b0f065e80, count: -14 ddb{0}> show registers rdi 0 rsi 0x40000 acpi_pdirpa+0x2be71 rbp 0xffff800030b8c500 rbx 0xffffffff8305ef72 pp_r600_decoded_lanes+0x2d62d rdx 0xffff8000011af840 rcx 0xffff8000ffff5478 rax 0x3ffff acpi_pdirpa+0x2be70 r8 0xffff800030b8c3e0 r9 0x8080808080808080 r10 0xfa1a9a52139a79fc r11 0xf2ee556ef015efd0 r12 0xfffffd80042ad570 r13 0xfffffd8003ac4dc0 r14 0x3 r15 0xffffffff rip 0xffffffff829d7925 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff800030b8c4f0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=376600 pid=53682 tcnt=3 stat=onproc flags process=9000000 proc=4000000 runpri=24, usrpri=50, slppri=24, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000ffff4548,0xffff8000ffff5c20 process=0xffff8000ffff0d98 user=0xffff800030b87000, vmspace=0xfffffd8068172c10 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 44454 251857 12796 0 2 0x8000000 syz-executor 44454 469796 12796 0 3 0xc000080 sbwait syz-executor 53682 10553 84794 0 2 0x9000000 syz-executor *53682 376600 84794 0 7 0xd000000 syz-executor 53682 223008 84794 0 2 0xd000000 syz-executor 20456 205692 87588 0 3 0x8000002 biowait syz-executor 50669 284972 87588 0 3 0x8000082 piperd syz-executor 19828 176267 87588 0 3 0x8000082 piperd syz-executor 24778 354065 87588 0 3 0x8000082 piperd syz-executor 95436 287918 87588 0 3 0x8000082 piperd syz-executor 71386 463010 87588 0 3 0x8000082 piperd syz-executor 12796 259408 87588 0 3 0x8000082 nanoslp syz-executor 84794 246970 87588 0 3 0x8000082 nanoslp syz-executor 85882 68358 1 0 3 0x18100083 ttyin getty 32224 100134 0 0 3 0x14200 bored sosplice 87588 346224 81366 0 2 0x8000002 syz-executor 81366 151366 8347 0 3 0x810008a sigsusp ksh 8347 433817 72089 0 3 0x18000098 kqread sshd-session 72089 7189 79965 0 3 0x18000092 kqread sshd-session 79965 283722 1 0 3 0x18000088 kqread sshd 76256 174546 34484 74 3 0x19100092 bpf pflogd 34484 321504 1 0 3 0x18000080 sbwait pflogd 87954 223414 74435 73 7 0x19100010 syslogd 74435 345059 1 0 3 0x18100082 sbwait syslogd 42252 380980 1 0 3 0x18100080 kqread resolvd 19957 491812 9799 77 3 0x18100092 kqread dhcpleased 35425 341648 9799 77 3 0x18100092 kqread dhcpleased 9799 302379 1 0 3 0x18000080 kqread dhcpleased 95346 399561 0 0 3 0x14200 bored smr 59032 249819 0 0 2 0x14200 zerothread 79046 398337 0 0 3 0x14200 aiodoned aiodoned 92066 460030 0 0 3 0x14200 syncer update 54557 189950 0 0 3 0x14200 cleaner cleaner 8998 3361 0 0 3 0x14200 reaper reaper 57593 418155 0 0 3 0x14200 pgdaemon pagedaemon 79372 326441 0 0 3 0x14200 bored viomb 51143 114134 0 0 3 0x40014200 acpi0 acpi0 90568 416066 0 0 3 0x40014200 idle1 9927 60349 0 0 3 0x14200 bored softnet3 34009 322524 0 0 3 0x14200 bored softnet2 57960 105089 0 0 3 0x14200 bored softnet1 51605 126304 0 0 3 0x14200 bored softnet0 64261 136091 0 0 3 0x14200 bored systqmp 4051 354961 0 0 3 0x14200 bored systq 82062 42294 0 0 3 0x14200 tmoslp softclockmp 14883 151128 0 0 3 0x40014200 tmoslp softclock 7017 174958 0 0 3 0x40014200 idle0 1 449632 0 0 3 0x8080082 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 53682 (syz-executor) thread 0xffff8000ffff5478 (376600) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff835481a8) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 unp_externalize+0x14e #2 soreceive+0xd3e sys/kern/uipc_socket.c:1022 #3 recvit+0x40a sys/kern/uipc_syscalls.c:1082 #4 sys_recvmmsg+0x3d3 sys/kern/uipc_syscalls.c:973 #5 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #5 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #6 Xsyscall+0x128 exclusive rwlock sbufrcv r = 0 (0xffff800010fdc8a8) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 rw_enter+0x41b sys/kern/kern_rwlock.c:309 #2 sblock+0xb7 sys/kern/uipc_socket2.c:549 #3 soreceive+0x298 sys/kern/uipc_socket.c:877 #4 recvit+0x40a sys/kern/uipc_syscalls.c:1082 #5 sys_recvmmsg+0x3d3 sys/kern/uipc_syscalls.c:973 #6 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #6 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #7 Xsyscall+0x128 Process 20456 (syz-executor) thread 0xffff8000ffff6020 (205692) exclusive rrwlock inode r = 0 (0xfffffd806bb25b48) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 rw_enter+0x41b sys/kern/kern_rwlock.c:309 #2 rrw_enter+0xbe sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:564 #5 vget+0x2bd sys/kern/vfs_subr.c:676 #6 ufs_ihashget+0x171 sys/ufs/ufs/ufs_ihash.c:95 #7 ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1201 #8 ufs_lookup+0x19f8 sys/ufs/ufs/ufs_lookup.c:478 #9 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85 #10 vfs_lookup+0x8fa sys/kern/vfs_lookup.c:566 #11 namei+0x7aa sys/kern/vfs_lookup.c:250 #12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1852 #13 syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline] #13 syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd8076fed808) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 rw_enter+0x41b sys/kern/kern_rwlock.c:309 #2 rrw_enter+0xbe sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:564 #5 vget+0x2bd sys/kern/vfs_subr.c:676 #6 cache_lookup+0x36e sys/kern/vfs_cache.c:222 #7 ufs_lookup+0x218 sys/ufs/ufs/ufs_lookup.c:160 #8 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85 #9 vfs_lookup+0x8fa sys/kern/vfs_lookup.c:566 #10 namei+0x7aa sys/kern/vfs_lookup.c:250 #11 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1852 #12 syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline] #12 syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577 #13 Xsyscall+0x128 Process 87954 (syslogd) thread 0xffff8000ffffd960 (223414) exclusive rrwlock inode r = 0 (0xfffffd806e4a74e0) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 rw_enter+0x41b sys/kern/kern_rwlock.c:309 #2 rrw_enter+0xbe sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:564 #5 sys_fsync+0x152 sys/kern/vfs_syscalls.c:2927 #6 syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline] #6 syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577 #7 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10225 10316K 10630K 166960K 13649 0 pcb 17 12K 12K 166960K 269 0 rtable 235 9K 9K 166960K 2715 0 pf 43 11K 11K 166960K 232 0 ifaddr 54 17K 17K 166960K 366 0 ifgroup 76 3K 3K 166960K 418 0 sysctl 1 0K 0K 166960K 1 0 counters 74 37K 37K 166960K 246 0 ioctlops 0 0K 4K 166960K 1633 0 iov 0 0K 12K 166960K 93 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1370 86K 86K 166960K 3383 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 16K 20K 166960K 36 0 VM map 2 1K 1K 166960K 2 0 sem 12 1K 1K 166960K 26 0 dirhash 18 3K 3K 166960K 105 0 ACPI 1697 195K 286K 166960K 12548 0 file desc 12 41K 97K 166960K 3291 0 sigio 0 0K 0K 166960K 30 0 proc 70 91K 140K 166960K 2624 0 subproc 104 6K 6K 166960K 1027 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 2 0K 0K 166960K 336 0 in_multi 99 7K 7K 166960K 944 0 ether_multi 1 0K 0K 166960K 20 0 mrt 0 0K 0K 166960K 14 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 91 413K 413K 166960K 91 0 exec 0 0K 1K 166960K 1422 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 194 71K 91K 166960K 26314 0 UVM aobj 60 3K 3K 166960K 63 0 pinsyscall 37 74K 104K 166960K 6210 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 147 0 NDP 19 0K 1K 166960K 261 0 temp 74 6816K 6884K 166960K 69647 0 kqueue 13 20K 26K 166960K 218 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 24 0 0 1 0 1 1 0 8 0 rtpcb 120 327 0 324 1 0 1 1 0 8 0 rtentry 112 950 0 846 4 1 3 4 0 8 0 unpcb 144 1077 0 1056 4 3 1 2 0 8 0 syncache 336 15 0 15 7 6 1 1 0 8 1 tcpqe 32 1 0 1 1 1 0 1 0 8 0 tcpcb 808 437 0 432 2 1 1 2 0 8 0 arp 120 170 0 151 1 0 1 1 0 8 0 inpcb 384 1864 0 1855 9 7 2 2 0 8 0 nd6 136 245 0 221 1 0 1 1 0 8 0 pkpcb 40 4 0 4 2 2 0 1 0 8 0 kcovpl 48 79 0 71 1 0 1 1 0 8 0 ppxss 1168 5 0 5 2 2 0 1 0 8 0 pffrag 232 13 0 13 3 3 0 1 0 482 0 pffrnode 88 13 0 13 3 3 0 1 0 8 0 pffrent 40 24 0 24 4 4 0 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 pfstitem 24 184 0 169 1 0 1 1 0 8 0 pfstkey 128 184 0 169 2 0 2 2 0 8 0 pfstate 376 184 0 169 6 3 3 5 0 8 1 pfrule 1344 21 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 3681 0 3227 39 10 29 29 0 8 0 art_table 32 3682 0 3227 4 0 4 4 0 8 0 art_node 16 933 0 842 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 3 1 0 1 1 0 8 0 semupl 112 8 0 8 1 1 0 1 0 8 0 semapl 112 24 0 14 1 0 1 1 0 8 0 shmpl 112 60 0 3 2 0 2 2 0 8 0 dirhash 1024 80 0 59 3 0 3 3 0 8 0 dino2pl 256 5063 0 3418 104 0 104 104 0 8 0 ffsino 272 5063 0 3418 112 2 110 110 0 8 0 nchpl 144 7921 0 6156 66 0 66 66 0 8 0 uvmvnodes 80 6718 0 0 138 0 138 138 0 8 0 vnodes 216 6718 0 0 374 0 374 374 0 8 0 namei 1024 29898 0 29898 6 5 1 2 0 8 1 percpumem 16 137 0 86 1 0 1 1 0 8 0 vcpupl 3904 3 0 0 1 0 1 1 0 8 0 vmpool 696 6 0 3 2 1 1 1 0 8 0 kstatmem 264 206 0 172 4 1 3 3 0 8 0 scsiplug 72 6 0 6 1 1 0 1 0 8 0 scxspl 216 54401 0 54400 16 15 1 8 1 8 0 plimitpl 152 330 0 313 1 0 1 1 0 8 0 sigapl 424 3449 0 3404 11 4 7 7 0 8 0 futexpl 64 25017 0 25017 8 7 1 1 0 8 1 knotepl 120 384 0 0 10 0 10 10 0 8 0 kqueuepl 216 384 0 375 1 0 1 1 0 8 0 pipepl 320 457 0 430 3 0 3 3 0 8 0 fdescpl 496 3430 0 3404 9 4 5 6 0 8 0 filepl 152 13497 0 13250 15 5 10 11 0 8 0 lockfpl 104 465 0 463 1 0 1 1 0 8 0 lockfspl 48 196 0 194 1 0 1 1 0 8 0 sessionpl 144 94 0 85 1 0 1 1 0 8 0 pgrppl 48 190 0 173 1 0 1 1 0 8 0 ucredpl 104 2053 0 2040 1 0 1 1 0 8 0 zombiepl 144 3404 0 3404 2 1 1 1 0 8 1 processpl 1152 3449 0 3404 5 1 4 5 0 8 0 procpl 648 5910 0 5862 8 2 6 6 0 8 0 srpgc 96 8 0 8 1 1 0 1 0 8 0 sosppl 168 13 0 13 7 7 0 1 0 8 0 sockpl 664 3279 0 3246 11 7 4 4 0 8 1 mcl64k 65536 34 0 0 3 0 3 3 0 8 0 mcl16k 16384 27 0 0 3 0 3 3 0 8 0 mcl12k 12288 13 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 18 0 0 3 0 3 3 0 8 0 mcl4k 4096 21 0 0 3 1 2 3 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 261 0 0 31 0 31 31 0 8 0 mtagpl 96 18 0 0 1 0 1 1 0 8 0 mbufpl 256 479 0 0 25 0 25 25 0 8 0 bufpl 280 13882 0 4972 637 0 637 637 0 8 0 anonpl 24 448283 0 445277 122 58 64 98 0 185 33 amapchunkpl 152 85591 0 85245 80 52 28 50 0 158 9 amappl16 200 7192 0 7177 43 29 14 15 0 8 12 amappl15 192 6 0 6 1 1 0 1 0 8 0 amappl14 184 262 0 250 1 0 1 1 0 8 0 amappl13 176 4 0 4 1 1 0 1 0 8 0 amappl12 168 5202 0 5176 4 2 2 3 0 8 0 amappl11 160 55 0 41 1 0 1 1 0 8 0 amappl10 152 18 0 18 1 1 0 1 0 8 0 amappl9 144 145 0 144 1 0 1 1 0 8 0 amappl8 136 19 0 17 1 0 1 1 0 8 0 amappl7 128 254 0 241 1 0 1 1 0 8 0 amappl6 120 876 0 875 1 0 1 1 0 8 0 amappl5 112 418 0 407 1 0 1 1 0 8 0 amappl4 104 527 0 507 1 0 1 1 0 8 0 amappl3 96 17427 0 17340 7 3 4 4 0 8 0 amappl2 88 1614 0 1550 2 0 2 2 0 8 0 amappl1 80 21458 0 20879 16 2 14 14 0 8 0 amappl 88 25358 0 25229 5 0 5 5 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 72 62 0 3 2 0 2 2 0 8 0 uaddrrnd 24 3436 0 3407 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3436 0 3407 1 0 1 1 0 8 0 vmmpekpl 168 24704 0 24660 3 0 3 3 0 8 0 vmmpepl 168 204007 0 202382 126 34 92 96 0 357 7 vmsppl 440 3435 0 3407 7 2 5 5 0 8 0 rwobjpl 56 58590 0 50915 112 0 112 112 0 8 2 pdppl 4096 6879 0 6817 219 141 78 87 0 8 16 pvpl 32 47119 0 0 379 1 378 378 0 265 0 pmappl 248 3435 0 3407 3 0 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 566 0 170 12 0 12 12 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:437 witness_checkorder(fffffd8076fedc48,9,0) at witness_checkorder+0x1024 rw_enter(fffffd8076fedc38,1) at rw_enter+0x122 rrw_enter(fffffd8076fedc38,1) at rrw_enter+0xbe sys/kern/kern_rwlock.c:464 VOP_LOCK(fffffd8057f20980,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd8057f20980,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:564 vfs_getcwd_common(fffffd8057f20980,fffffd8057f202c0,0,0,200,0,cd0c88eace848f19) at vfs_getcwd_common+0xd1 sys/kern/vfs_getcwd.c:287 vn_isunder(fffffd8057f20980,fffffd8057f202c0,ffff8000ffff5478) at vn_isunder+0x56 sys/kern/vfs_vnops.c:688 unp_externalize(fffffd806cb10a00,101,0) at unp_externalize+0x286 sys/kern/uipc_usrreq.c:1088 soreceive(ffff800010fdc7d8,ffff800030b8caa8,ffff800030b8ca58,0,ffff800030b8ca98,ffff800030b8cc1c,f5acfaa2eb5ae0d2) at soreceive+0xd3e sys/kern/uipc_socket.c:1022 recvit(ffff8000ffff5478,8,ffff800030b8cbf0,0,ffff800030b8cbe0) at recvit+0x40a sys/kern/uipc_syscalls.c:1082 sys_recvmmsg(ffff8000ffff5478,ffff800030b8cdb0,ffff800030b8cd00) at sys_recvmmsg+0x3d3 sys/kern/uipc_syscalls.c:973 syscall(ffff800030b8cdb0) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] syscall(ffff800030b8cdb0) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe6b0f065e80, count: -14 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800029b7bff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff83547fa0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff83547fa0) at __mp_lock+0x192 sys/kern/kern_lock.c:144 __mp_acquire_count(ffffffff83547fa0,1) at __mp_acquire_count+0x58 mi_switch() at mi_switch+0x658 sys/kern/sched_bsd.c:460 sleep_finish(0,1) at sleep_finish+0x229 sys/kern/kern_synch.c:416 vwaitforio(fffffd806e267c20,0,ffffffff8308bb44,ffffffffffffffff) at vwaitforio+0xd2 ffs_fsync(ffff80002a06a890) at ffs_fsync+0x376 sys/ufs/ffs/ffs_vnops.c:482 VOP_FSYNC(fffffd806e267c20,fffffd807f7d3820,1,ffff8000ffffd960) at VOP_FSYNC+0x108 sys/kern/vfs_vops.c:311 sys_fsync(ffff8000ffffd960,ffff80002a06aa40,ffff80002a06a990) at sys_fsync+0x16f sys/kern/vfs_syscalls.c:2927 syscall(ffff80002a06aa40) at syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline] syscall(ffff80002a06aa40) at syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x79ce04957fd0, count: -13