witness: lock order reversal: 1st 0xfffffd806f74b820 fdlock (&newfdp->fd_fd.fd_lock) 2nd 0xfffffd8055ec33d0 inode (&ip->i_lock) lock order data w2 -> w1 missing lock order data w1 -> w2 missing Stopped at db_enter+0x18: addq $0x8,%rsp ddb{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic the kernel did not panic ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 witness_checkorder(fffffd8055ec33d0,9,0) at witness_checkorder+0x10f3 witness_debugger sys/kern/subr_witness.c:2502 [inline] witness_checkorder(fffffd8055ec33d0,9,0) at witness_checkorder+0x10f3 sys/kern/subr_witness.c:1105 rw_enter(fffffd8055ec33c0,81) at rw_enter+0xd1 sys/kern/kern_rwlock.c:250 rrw_enter(fffffd8055ec33c0,81) at rrw_enter+0x8b sys/kern/kern_rwlock.c:461 VOP_LOCK(fffffd80787e1018,81) at VOP_LOCK+0x87 sys/kern/vfs_vops.c:614 vn_lock(fffffd80787e1018,81) at vn_lock+0x84 sys/kern/vfs_vnops.c:579 uvn_get(fffffd804f2d6840,0,ffff8000256b6de8,ffff8000256b6db8,0,2) at uvn_get+0x256 uvm_vnode_lock sys/uvm/uvm_vnode.c:1499 [inline] uvn_get(fffffd804f2d6840,0,ffff8000256b6de8,ffff8000256b6db8,0,2) at uvn_get+0x256 sys/uvm/uvm_vnode.c:993 uvm_fault_lower(ffff8000256b6f50,ffff8000256b6f88,ffff8000256b6ed0,0) at uvm_fault_lower+0x302 sys/uvm/uvm_fault.c:1251 uvm_fault(fffffd806f0f8458,20000000,0,2) at uvm_fault+0x240 sys/uvm/uvm_fault.c:638 kpageflttrap(ffff8000256b70e0,20000100) at kpageflttrap+0x1fd sys/arch/amd64/amd64/trap.c:264 kerntrap(ffff8000256b70e0) at kerntrap+0xef sys/arch/amd64/amd64/trap.c:318 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b copyout() at copyout+0x53 syscall(ffff8000256b7310) at syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000256b7310) at syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xd9537beb3d0, count: -15 ddb{1}> show registers rdi 0xffff80002349c000 rsi 0x13043 mp_pdirpa+0x203d rbp 0xffff8000256b6a60 rbx 0x3 rdx 0xffff80002349c000 rcx 0x13042 mp_pdirpa+0x203c rax 0xffffffff8143b2a7 db_enter+0x17 r8 0xffffffff81222ddc witness_checkorder+0x10cc r9 0x5 r10 0x939be8dc1d511c25 r11 0x2a8d7f992ef90af8 r12 0xfffffd8002dab7c0 r13 0 r14 0 r15 0 rip 0xffffffff8143b2a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000256b6a50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=51350 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffff8000212102a8,0xffff800021210fd8 process=0xffff8000ffff9d58 user=0xffff8000256b2000, vmspace=0xfffffd806f0f8458 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 89058 320911 68161 32767 2 0x10 syz-executor.0 63219 359347 78864 32767 7 0x10 syz-executor.1 *63219 51350 78864 32767 7 0x4000010 syz-executor.1 21025 266318 0 0 3 0x14200 bored sosplice 78864 396199 65098 32767 3 0x90 nanoslp syz-executor.1 68161 270073 56842 32767 3 0x90 nanoslp syz-executor.0 65098 190896 9596 0 3 0x82 wait syz-executor.1 56842 376578 9596 0 3 0x82 wait syz-executor.0 9596 488167 48672 0 3 0x82 thrsleep syz-fuzzer 9596 307305 48672 0 3 0x4000082 nanoslp syz-fuzzer 9596 58032 48672 0 3 0x4000082 kqread syz-fuzzer 9596 110280 48672 0 3 0x4000082 thrsleep syz-fuzzer 9596 387471 48672 0 3 0x4000082 thrsleep syz-fuzzer 9596 474754 48672 0 3 0x4000082 thrsleep syz-fuzzer 9596 486568 48672 0 3 0x4000082 thrsleep syz-fuzzer 9596 340451 48672 0 3 0x4000082 nanoslp syz-fuzzer 48672 112848 84782 0 3 0x10008a sigsusp ksh 84782 123187 10432 0 3 0x9a select sshd 56458 389613 1 0 3 0x100083 ttyin getty 10432 469704 1 0 3 0x88 select sshd 44567 12544 87745 73 3 0x100090 kqread syslogd 87745 173631 1 0 3 0x100082 netio syslogd 97055 440876 1 0 3 0x100080 kqread resolvd 70115 485209 79071 77 3 0x100092 kqread dhcpleased 39965 177218 79071 77 3 0x100092 kqread dhcpleased 79071 273848 1 0 3 0x80 kqread dhcpleased 56511 253941 0 0 3 0x14200 bored smr 56704 341042 0 0 2 0x14200 zerothread 40169 32178 0 0 3 0x14200 aiodoned aiodoned 95566 132416 0 0 3 0x14200 syncer update 89638 357866 0 0 3 0x14200 cleaner cleaner 22500 179742 0 0 3 0x14200 reaper reaper 37343 369122 0 0 3 0x14200 pgdaemon pagedaemon 71195 123355 0 0 3 0x14200 bored crynlk 17303 238393 0 0 3 0x14200 bored crypto 47283 290193 0 0 3 0x14200 bored viomb 29670 142972 0 0 3 0x40014200 acpi0 acpi0 10145 156197 0 0 3 0x40014200 idle1 52 488950 0 0 3 0x14200 bored softnet 92018 227332 0 0 3 0x14200 bored systqmp 44605 157313 0 0 3 0x14200 bored systq 4922 395191 0 0 3 0x40014200 bored softclock 21300 246307 0 0 3 0x40014200 idle0 1 384281 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 63219 (syz-executor.1) thread 0xffff800021211ce8 (51350) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff829423a8) #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+0x224 sys/uvm/uvm_fault.c:637 #2 kpageflttrap+0x1fd sys/arch/amd64/amd64/trap.c:264 #3 kerntrap+0xef sys/arch/amd64/amd64/trap.c:318 #4 alltraps_kern_meltdown+0x7b #5 copyout+0x53 #6 syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline] #6 syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587 #7 Xsyscall+0x128 exclusive rwlock fdlock r = 0 (0xfffffd806f74b820) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1182 #1 sys_socketpair+0x20f #2 syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline] #2 syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587 #3 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10115 6354K 6380K 78643K 11205 0 pcb 13 8K 8K 78643K 13 0 rtable 106 3K 3K 78643K 168 0 ifaddr 39 10K 10K 78643K 39 0 counters 44 34K 34K 78643K 44 0 ioctlops 0 0K 2K 78643K 91 0 iov 0 0K 0K 78643K 1086 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 6 0 vnodes 1216 76K 76K 78643K 1222 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 8 0 VM map 2 1K 1K 78643K 2 0 sem 11 1K 1K 78643K 13 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12598 0 file desc 8 25K 33K 78643K 23753 0 sigio 0 0K 0K 78643K 20 0 proc 56 74K 99K 78643K 285 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 376 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 670 73K 73K 78643K 294220 0 UVM aobj 10 2K 2K 78643K 12 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 4205K 4269K 78643K 49585 0 kqueue 10 14K 19K 78643K 19 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> 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 21 0 18 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 44280 0 44263 1 0 1 1 0 8 0 syncache 296 4 0 4 1 1 0 1 0 8 0 tcpqe 32 543 0 543 5 5 0 4 0 8 0 tcpcb 736 21 0 17 1 0 1 1 0 8 0 arp 120 6 0 0 1 0 1 1 0 8 0 inpcb 304 8336 0 8328 11 9 2 2 0 8 1 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 256 189 0 0 12 0 12 12 0 8 0 art_table 32 190 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 sysvmsgpl 40 20 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 9 0 0 1 0 1 1 0 8 0 shmpl 112 9 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 27546 0 26142 88 0 88 88 0 8 0 ffsino 272 27546 0 26142 95 1 94 94 0 8 0 nchpl 144 60731 0 59116 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 121376 0 121376 2 1 1 1 0 8 1 percpumem 16 34 0 0 1 0 1 1 0 8 0 scxspl 216 154539 0 154539 11 10 1 8 0 8 1 plimitpl 152 19 0 9 1 0 1 1 0 8 0 sigapl 424 23976 0 23940 5 0 5 5 0 8 0 futexpl 56 143829 0 143829 1 0 1 1 0 8 1 knotepl 112 50 0 0 2 0 2 2 0 8 0 kqueuepl 216 5770 0 5764 3 2 1 2 0 8 0 pipepl 336 1096 0 1086 14 12 2 2 0 8 1 fdescpl 496 23959 0 23940 3 0 3 3 0 8 0 filepl 152 102726 0 102611 8 3 5 6 0 8 0 lockfpl 104 79 0 75 1 0 1 1 0 8 0 lockfspl 48 30 0 26 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 3535 0 3523 1 0 1 1 0 8 0 zombiepl 144 23940 0 23940 2 1 1 1 0 8 1 processpl 1072 23976 0 23940 3 0 3 3 0 8 0 procpl 672 49722 0 49678 13 9 4 5 0 8 0 sosppl 168 3154 0 3154 8 7 1 1 0 8 1 sockpl 480 52677 0 52649 14 9 5 6 0 8 1 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 10 0 0 2 0 2 2 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 33 0 0 4 1 3 3 0 8 0 mcl2k2 2112 17 0 0 2 0 2 2 0 8 0 mcl2k 2048 537 0 0 61 25 36 61 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 915 0 0 34 0 34 34 0 8 0 bufpl 280 27091 0 20759 453 0 453 453 0 8 0 anonpl 24 6073826 0 5974302 700 7 693 699 0 186 0 amapchunkpl 152 666150 0 662506 156 3 153 154 0 158 0 amappl16 200 49210 0 45755 183 1 182 182 0 8 0 amappl15 192 5 0 1 1 0 1 1 0 8 0 amappl14 184 4 0 1 1 0 1 1 0 8 0 amappl13 176 30 0 27 1 0 1 1 0 8 0 amappl12 168 4 0 3 2 1 1 1 0 8 0 amappl11 160 11897 0 11884 1 0 1 1 0 8 0 amappl10 152 11910 0 11902 1 0 1 1 0 8 0 amappl9 144 34 0 32 1 0 1 1 0 8 0 amappl8 136 374 0 319 2 0 2 2 0 8 0 amappl7 128 70 0 54 1 0 1 1 0 8 0 amappl6 120 111 0 98 1 0 1 1 0 8 0 amappl5 112 26112 0 26092 1 0 1 1 0 8 0 amappl4 104 24253 0 24221 1 0 1 1 0 8 0 amappl3 96 1808 0 1805 1 0 1 1 0 8 0 amappl2 88 484 0 431 2 0 2 2 0 8 0 amappl1 80 410443 0 410000 15 5 10 12 0 8 0 amappl 88 280244 0 279658 14 0 14 14 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 11 0 2 1 0 1 1 0 8 0 uaddrrnd 24 23959 0 23940 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 23959 0 23940 1 0 1 1 0 8 0 vmmpekpl 168 111970 0 111949 2 0 2 2 0 8 0 vmmpepl 168 2736676 0 2731272 385 148 237 373 0 357 2 vmsppl 368 23958 0 23940 2 0 2 2 0 8 0 rwobjpl 56 459123 0 454501 72 6 66 66 0 8 0 pdppl 4096 47925 0 47880 71 26 45 49 0 8 0 pvpl 32 13853956 0 13750747 973 18 955 970 0 265 0 pmappl 224 23958 0 23940 2 0 2 2 0 8 0 extentpl 40 58 0 40 1 0 1 1 0 8 0 phpool 112 398 0 68 11 0 11 11 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff82807ff0) 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x25 kd_curproc sys/dev/kcov.c:559 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x25 sys/dev/kcov.c:143 __mp_lock(ffffffff829421a0) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff829421a0) at __mp_lock+0x133 sys/kern/kern_lock.c:147 softintr_dispatch(0) at softintr_dispatch+0x4e sys/arch/amd64/amd64/softintr.c:90 Xsoftclock() at Xsoftclock+0x1f end of kernel end trace frame: 0x7f7ffffc9e80, count: -7 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x18: addq $0x8,%rsp ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 witness_checkorder(fffffd8055ec33d0,9,0) at witness_checkorder+0x10f3 witness_debugger sys/kern/subr_witness.c:2502 [inline] witness_checkorder(fffffd8055ec33d0,9,0) at witness_checkorder+0x10f3 sys/kern/subr_witness.c:1105 rw_enter(fffffd8055ec33c0,81) at rw_enter+0xd1 sys/kern/kern_rwlock.c:250 rrw_enter(fffffd8055ec33c0,81) at rrw_enter+0x8b sys/kern/kern_rwlock.c:461 VOP_LOCK(fffffd80787e1018,81) at VOP_LOCK+0x87 sys/kern/vfs_vops.c:614 vn_lock(fffffd80787e1018,81) at vn_lock+0x84 sys/kern/vfs_vnops.c:579 uvn_get(fffffd804f2d6840,0,ffff8000256b6de8,ffff8000256b6db8,0,2) at uvn_get+0x256 uvm_vnode_lock sys/uvm/uvm_vnode.c:1499 [inline] uvn_get(fffffd804f2d6840,0,ffff8000256b6de8,ffff8000256b6db8,0,2) at uvn_get+0x256 sys/uvm/uvm_vnode.c:993 uvm_fault_lower(ffff8000256b6f50,ffff8000256b6f88,ffff8000256b6ed0,0) at uvm_fault_lower+0x302 sys/uvm/uvm_fault.c:1251 uvm_fault(fffffd806f0f8458,20000000,0,2) at uvm_fault+0x240 sys/uvm/uvm_fault.c:638 kpageflttrap(ffff8000256b70e0,20000100) at kpageflttrap+0x1fd sys/arch/amd64/amd64/trap.c:264 kerntrap(ffff8000256b70e0) at kerntrap+0xef sys/arch/amd64/amd64/trap.c:318 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b copyout() at copyout+0x53 syscall(ffff8000256b7310) at syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000256b7310) at syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xd9537beb3d0, count: -15