witness: lock order reversal: 1st 0xffffffff8277e670 netlock (netlock) 2nd 0xfffffd807a64a0a0 inode (&ip->i_lock) lock order "&ip->i_lock"(rrwlock) -> "netlock"(rwlock) first seen at: #0 witness_checkorder+0x65e witness_lock_order_add sys/kern/subr_witness.c:2463 [inline] #0 witness_checkorder+0x65e sys/kern/subr_witness.c:880 #1 rw_enter_write+0x5b sys/kern/kern_rwlock.c:127 #2 uvn_get+0xeb uvm_vnode_lock sys/uvm/uvm_vnode.c:1501 [inline] #2 uvn_get+0xeb sys/uvm/uvm_vnode.c:993 #3 uvm_fault+0xa41 sys/uvm/uvm_fault.c:1073 #4 kpageflttrap+0x202 sys/arch/amd64/amd64/trap.c:265 #5 kerntrap+0xef sys/arch/amd64/amd64/trap.c:321 #6 alltraps_kern_meltdown+0x7b #7 copyin+0x53 #8 sys_connect+0x9b sys/kern/uipc_syscalls.c:362 #9 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #9 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 #10 Xsyscall+0x128 lock order "netlock"(rwlock) -> "&ip->i_lock"(rrwlock) first seen at: #0 witness_checkorder+0x65e witness_lock_order_add sys/kern/subr_witness.c:2463 [inline] #0 witness_checkorder+0x65e sys/kern/subr_witness.c:880 #1 rw_enter+0xd4 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 #4 vn_lock+0x6c sys/kern/vfs_vnops.c:575 #5 vget+0x1c6 sys/kern/vfs_subr.c:671 #6 ktrwriteraw+0x138 sys/kern/kern_ktrace.c:659 #7 ktrstruct+0x169 ktrwrite2 sys/kern/kern_ktrace.c:627 [inline] #7 ktrstruct+0x169 sys/kern/kern_ktrace.c:311 #8 sys_connect+0x246 #9 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #9 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 #10 Xsyscall+0x128 Stopped at db_enter+0x18: 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+0x18 sys/arch/amd64/amd64/db_interface.c:398 witness_checkorder(fffffd807a64a0a0,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd807a64a0a0,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd807a64a090,1) at rw_enter+0xd4 rrw_enter(fffffd807a64a090,1) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd807b4e6500,2001) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 vn_lock(fffffd807b4e6500,2001) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 vget(fffffd807b4e6500,2001) at vget+0x1c6 sys/kern/vfs_subr.c:671 ktrwriteraw(ffff80002123c538,fffffd807b4e6500,fffffd807f7b7960,ffff8000214a1220,ffff8000214a1200) at ktrwriteraw+0x138 sys/kern/kern_ktrace.c:659 ktrstruct(ffff80002123c538,ffffffff823afafa,fffffd8067c7f420,10) at ktrstruct+0x169 ktrwrite2 sys/kern/kern_ktrace.c:627 [inline] ktrstruct(ffff80002123c538,ffffffff823afafa,fffffd8067c7f420,10) at ktrstruct+0x169 sys/kern/kern_ktrace.c:311 sys_connect(ffff80002123c538,ffff8000214a1368,ffff8000214a13b0) at sys_connect+0x246 syscall(ffff8000214a1430) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000214a1430) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x994868ecc70, count: -12 ddb{0}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be68 rbp 0xffff8000214a0e30 rbx 0x3 rdx 0xffff800000ac0040 rcx 0x3 rax 0x3ffff acpi_pdirpa+0x2be67 r8 0xffffffff81e34c43 witness_checkorder+0xf33 r9 0x5 r10 0x2e3c9342c7be6461 r11 0x525dbd0812724ca4 r12 0xffffffff82844940 w_lodata+0x47d80 r13 0 r14 0xffffffff82843080 w_lodata+0x464c0 r15 0xfffffd8002c9b500 rip 0xffffffff82243a18 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000214a0e20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=253719 stat=onproc flags process=0 proc=4000001 pri=32, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffff80002123d208,0xffff80002123cf88 process=0xffff800021234c70 user=0xffff80002149c000, vmspace=0xfffffd806e951b88 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 47205 298465 733 0 2 0 syz-executor.1 *47205 253719 733 0 7 0x4000001 syz-executor.1 12004 171629 37343 0 2 0 syz-executor.0 12004 422637 37343 0 7 0x4000000 syz-executor.0 733 363939 77599 0 3 0x82 nanosleep syz-executor.1 62357 444216 0 0 3 0x14200 acct acct 37343 130156 77599 0 3 0x82 nanosleep syz-executor.0 92322 187388 0 0 3 0x14200 bored sosplice 77599 14768 91111 0 3 0x82 thrsleep syz-fuzzer 77599 486763 91111 0 3 0x4000082 thrsleep syz-fuzzer 77599 518760 91111 0 3 0x4000082 thrsleep syz-fuzzer 77599 464318 91111 0 3 0x4000082 thrsleep syz-fuzzer 77599 32862 91111 0 3 0x4000082 thrsleep syz-fuzzer 77599 372948 91111 0 3 0x4000082 thrsleep syz-fuzzer 77599 344237 91111 0 3 0x4000082 thrsleep syz-fuzzer 77599 497599 91111 0 3 0x4000082 kqread syz-fuzzer 91111 129063 60494 0 3 0x10008a pause ksh 60494 68259 78390 0 3 0x92 select sshd 29425 11880 1 0 3 0x100083 ttyin getty 78390 440206 1 0 3 0x80 select sshd 59016 336283 20806 74 3 0x100092 bpf pflogd 20806 377492 1 0 3 0x80 netio pflogd 74911 209742 41480 73 3 0x100090 kqread syslogd 41480 98136 1 0 3 0x100082 netio syslogd 57301 188510 1 77 3 0x100090 poll dhclient 93361 62860 1 0 3 0x80 poll dhclient 46239 113539 0 0 3 0x14200 bored smr 77958 219704 0 0 2 0x14200 zerothread 53833 392225 0 0 3 0x14200 aiodoned aiodoned 95932 102532 0 0 3 0x14200 syncer update 59318 400088 0 0 3 0x14200 cleaner cleaner 15126 146229 0 0 3 0x14200 reaper reaper 67737 119156 0 0 3 0x14200 pgdaemon pagedaemon 47558 452856 0 0 3 0x14200 bored crynlk 86517 30599 0 0 3 0x14200 bored crypto 75843 425091 0 0 3 0x14200 bored viomb 86286 171442 0 0 3 0x40014200 acpi0 acpi0 51974 513636 0 0 3 0x40014200 idle1 98689 323988 0 0 3 0x14200 bored softnet 31800 247065 0 0 3 0x14200 bored systqmp 7618 286152 0 0 3 0x14200 bored systq 95577 338715 0 0 3 0x40014200 bored softclock 25166 491800 0 0 3 0x40014200 idle0 1 125814 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 47205 (syz-executor.1) thread 0xffff80002123c538 (253719) exclusive rwlock netlock r = 0 (0xffffffff8277e670) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1164 #1 uvn_io+0x31d sys/uvm/uvm_vnode.c:1224 #2 uvn_get+0x473 sys/uvm/uvm_vnode.c:1083 #3 uvm_fault+0xa41 sys/uvm/uvm_fault.c:1073 #4 kpageflttrap+0x202 sys/arch/amd64/amd64/trap.c:265 #5 kerntrap+0xef sys/arch/amd64/amd64/trap.c:321 #6 alltraps_kern_meltdown+0x7b #7 copyin+0x53 #8 sys_connect+0x9b sys/kern/uipc_syscalls.c:362 #9 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #9 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 #10 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 1 (0xffffffff828cea78) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1164 #1 syscall+0x3fd mi_syscall sys/sys/syscall_mi.h:93 [inline] #1 syscall+0x3fd sys/arch/amd64/amd64/trap.c:590 #2 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9545 6574K 6969K 78643K 11821 0 pcb 13 8K 8K 78643K 64 0 rtable 102 3K 4K 78643K 415 0 ifaddr 72 13K 14K 78643K 121 0 sysctl 2 0K 0K 78643K 2 0 counters 43 33K 34K 78643K 59 0 ioctlops 0 0K 4K 78643K 1531 0 iov 0 0K 12K 78643K 48 0 mount 1 1K 1K 78643K 1 0 vnodes 1218 77K 77K 78643K 1589 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 12 0K 0K 78643K 94 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1825 197K 290K 78643K 13109 0 file desc 6 17K 25K 78643K 1425 0 sigio 0 0K 0K 78643K 6 0 proc 64 63K 83K 78643K 588 0 subproc 32 2K 2K 78643K 68 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 89 0 in_multi 29 1K 2K 78643K 127 0 ether_multi 1 0K 0K 78643K 14 0 mrt 0 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 2K 78643K 449 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 137 57K 57K 78643K 4208 0 UVM aobj 7 2K 2K 78643K 7 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 37 0 NDP 13 0K 0K 78643K 33 0 temp 134 3962K 4026K 78643K 9102 0 kqueue 3 4K 16K 78643K 46 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 10 0 4 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 120 52 0 50 1 0 1 1 0 8 0 rtentry 112 86 0 45 2 0 2 2 0 8 0 unpcb 120 203 0 193 1 0 1 1 0 8 0 syncache 296 16 0 16 4 4 0 1 0 8 0 tcpqe 32 789 0 789 3 3 0 1 0 8 0 tcpcb 736 187 0 179 3 1 2 2 0 8 0 inpcb 296 461 0 450 5 3 2 2 0 8 1 rttmr 72 2 0 2 1 1 0 1 0 8 0 nd6 48 18 0 14 1 0 1 1 0 8 0 pkpcb 40 4 0 4 2 2 0 1 0 8 0 kcovpl 48 4 0 2 1 0 1 1 0 8 0 ppxss 1128 4 0 4 3 3 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 37 0 23 1 0 1 1 0 8 0 pfstkey 112 37 0 23 1 0 1 1 0 8 0 pfstate 328 37 0 23 3 0 3 3 0 8 0 pfrule 1360 29 0 24 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 397 0 224 14 2 12 14 0 8 0 art_table 32 398 0 224 2 0 2 2 0 8 0 art_node 16 85 0 47 1 0 1 1 0 8 0 sysvmsgpl 40 40 0 18 1 0 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 92 0 82 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 2983 0 1580 89 0 89 89 0 8 0 ffsino 272 2983 0 1580 95 1 94 94 0 8 0 nchpl 144 4672 0 3079 60 0 60 60 0 8 0 uvmvnodes 72 3319 0 0 61 0 61 61 0 8 0 vnodes 208 3319 0 0 175 0 175 175 0 8 0 namei 1024 11666 0 11666 2 1 1 1 0 8 1 percpumem 16 40 0 8 1 0 1 1 0 8 0 vcpupl 1984 4 0 0 1 0 1 1 0 8 0 vmpool 560 6 0 2 1 0 1 1 0 8 0 scxspl 216 14236 0 14236 12 10 2 8 0 8 2 plimitpl 152 53 0 45 1 0 1 1 0 8 0 sigapl 424 1637 0 1602 4 0 4 4 0 8 0 futexpl 56 8696 0 8696 1 0 1 1 0 8 1 knotepl 112 132 0 112 1 0 1 1 0 8 0 kqueuepl 152 1116 0 1114 1 0 1 1 0 8 0 pipepl 304 108 0 97 4 2 2 2 0 8 1 fdescpl 496 1619 0 1602 3 0 3 3 0 8 0 filepl 152 5343 0 5238 7 2 5 5 0 8 0 lockfpl 104 115 0 114 1 0 1 1 0 8 0 lockfspl 48 45 0 44 1 0 1 1 0 8 0 sessionpl 144 20 0 9 1 0 1 1 0 8 0 pgrppl 48 20 0 9 1 0 1 1 0 8 0 ucredpl 96 384 0 375 1 0 1 1 0 8 0 zombiepl 144 1602 0 1602 2 1 1 1 0 8 1 processpl 1056 1637 0 1602 3 0 3 3 0 8 0 procpl 656 3551 0 3507 6 2 4 5 0 8 0 sosppl 168 7 0 7 3 3 0 1 0 8 0 sockpl 400 721 0 698 5 1 4 4 0 8 0 mcl64k 65536 19 0 0 3 0 3 3 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 6 0 0 1 0 1 1 0 8 0 mcl8k 8192 10 0 0 2 0 2 2 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 198 0 0 23 0 23 23 0 8 0 mtagpl 96 78 0 0 2 0 2 2 0 8 0 mbufpl 256 406 0 0 25 0 25 25 0 8 0 bufpl 280 5223 0 181 361 0 361 361 0 8 0 anonpl 16 140803 0 121154 91 11 80 88 0 124 0 amapchunkpl 152 6725 0 6388 17 3 14 14 0 158 0 amappl16 192 4890 0 4004 57 12 45 55 0 8 0 amappl15 184 176 0 174 1 0 1 1 0 8 0 amappl14 176 24 0 20 1 0 1 1 0 8 0 amappl13 168 46 0 42 1 0 1 1 0 8 0 amappl12 160 10 0 6 1 0 1 1 0 8 0 amappl11 152 697 0 680 1 0 1 1 0 8 0 amappl10 144 572 0 566 1 0 1 1 0 8 0 amappl9 136 155 0 155 2 2 0 1 0 8 0 amappl8 128 157 0 119 2 0 2 2 0 8 0 amappl7 120 273 0 265 1 0 1 1 0 8 0 amappl6 112 642 0 629 1 0 1 1 0 8 0 amappl5 104 2191 0 2170 1 0 1 1 0 8 0 amappl4 96 923 0 894 1 0 1 1 0 8 0 amappl3 88 155 0 147 1 0 1 1 0 8 0 amappl2 80 10691 0 10618 2 0 2 2 0 8 0 amappl1 72 58716 0 58212 26 16 10 19 0 8 0 amappl 80 3864 0 3782 2 0 2 2 0 84 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 6 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1625 0 1604 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1625 0 1604 1 0 1 1 0 8 0 vmmpekpl 168 12750 0 12714 2 0 2 2 0 8 0 vmmpepl 168 215180 0 212936 148 48 100 126 0 357 2 vmsppl 368 1624 0 1604 2 0 2 2 0 8 0 pdppl 4096 3257 0 3212 70 25 45 46 0 8 0 pvpl 32 582448 0 559557 215 25 190 207 0 265 3 pmappl 232 1624 0 1604 3 1 2 2 0 8 0 extentpl 40 57 0 39 1 0 1 1 0 8 0 phpool 112 343 0 34 9 0 9 9 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 witness_checkorder(fffffd807a64a0a0,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd807a64a0a0,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd807a64a090,1) at rw_enter+0xd4 rrw_enter(fffffd807a64a090,1) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd807b4e6500,2001) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 vn_lock(fffffd807b4e6500,2001) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 vget(fffffd807b4e6500,2001) at vget+0x1c6 sys/kern/vfs_subr.c:671 ktrwriteraw(ffff80002123c538,fffffd807b4e6500,fffffd807f7b7960,ffff8000214a1220,ffff8000214a1200) at ktrwriteraw+0x138 sys/kern/kern_ktrace.c:659 ktrstruct(ffff80002123c538,ffffffff823afafa,fffffd8067c7f420,10) at ktrstruct+0x169 ktrwrite2 sys/kern/kern_ktrace.c:627 [inline] ktrstruct(ffff80002123c538,ffffffff823afafa,fffffd8067c7f420,10) at ktrstruct+0x169 sys/kern/kern_ktrace.c:311 sys_connect(ffff80002123c538,ffff8000214a1368,ffff8000214a13b0) at sys_connect+0x246 syscall(ffff8000214a1430) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000214a1430) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x994868ecc70, count: -12 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800020d68ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 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+0x37 kd_curproc sys/dev/kcov.c:570 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x37 sys/dev/kcov.c:143 __mp_lock(ffffffff828ce870) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff828ce870) at __mp_lock+0x133 sys/kern/kern_lock.c:147 end trace frame: 0x0, count: -5