witness: lock order reversal: 1st 0xffffffff8277e670 netlock (netlock) 2nd 0xfffffd807d7c15e8 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{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:398 witness_checkorder(fffffd807d7c15e8,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd807d7c15e8,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd807d7c15d8,1) at rw_enter+0xd4 rrw_enter(fffffd807d7c15d8,1) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd80704e3018,2001) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 vn_lock(fffffd80704e3018,2001) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 vget(fffffd80704e3018,2001) at vget+0x1c6 sys/kern/vfs_subr.c:671 ktrwriteraw(ffff800021272538,fffffd80704e3018,fffffd807f7b7960,ffff800022cb1ca0,ffff800022cb1c80) at ktrwriteraw+0x138 sys/kern/kern_ktrace.c:659 ktrstruct(ffff800021272538,ffffffff823afafa,fffffd807d62d320,10) at ktrstruct+0x169 ktrwrite2 sys/kern/kern_ktrace.c:627 [inline] ktrstruct(ffff800021272538,ffffffff823afafa,fffffd807d62d320,10) at ktrstruct+0x169 sys/kern/kern_ktrace.c:311 sys_connect(ffff800021272538,ffff800022cb1de8,ffff800022cb1e30) at sys_connect+0x246 syscall(ffff800022cb1eb0) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800022cb1eb0) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5c778b68670, count: -12 ddb{1}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be68 rbp 0xffff800022cb18b0 rbx 0x3 rdx 0xffff800000af5a40 rcx 0x3 rax 0x3ffff acpi_pdirpa+0x2be67 r8 0xffffffff81e34c43 witness_checkorder+0xf33 r9 0x5 r10 0x76bca44987b69756 r11 0x99c7fff3ec6d4ba6 r12 0xffffffff82849c70 w_lodata+0x4d0b0 r13 0 r14 0xffffffff82849bc0 w_lodata+0x4d000 r15 0xfffffd8002c9b500 rip 0xffffffff82243a18 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022cb18a0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=475090 stat=onproc flags process=0 proc=4000001 pri=17, usrpri=75, nice=20 forw=0xffffffffffffffff, list=0xffff8000212727c8,0xffff800021272f88 process=0xffff800021234010 user=0xffff800022cac000, vmspace=0xfffffd807eff98a0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 74224 466948 17457 0 7 0 syz-executor.1 74224 515267 17457 0 3 0x4000080 fsleep syz-executor.1 33420 88522 91645 0 2 0x1 syz-executor.0 *33420 475090 91645 0 7 0x4000001 syz-executor.0 17457 70107 63597 0 3 0x82 nanosleep syz-executor.1 91645 273650 63597 0 3 0x82 nanosleep syz-executor.0 63597 284145 15787 0 3 0x82 kqread syz-fuzzer 63597 132653 15787 0 3 0x4000082 nanosleep syz-fuzzer 63597 467672 15787 0 3 0x4000082 thrsleep syz-fuzzer 63597 37089 15787 0 3 0x4000082 thrsleep syz-fuzzer 63597 345110 15787 0 3 0x4000082 thrsleep syz-fuzzer 63597 32134 15787 0 3 0x4000082 thrsleep syz-fuzzer 63597 331598 15787 0 3 0x4000082 thrsleep syz-fuzzer 63597 399100 15787 0 3 0x4000082 thrsleep syz-fuzzer 15787 192289 27837 0 3 0x10008a pause ksh 27837 451265 39942 0 3 0x92 select sshd 83101 388509 1 0 3 0x100083 ttyin getty 39942 501038 1 0 3 0x80 select sshd 5480 180540 29921 74 3 0x100092 bpf pflogd 29921 51854 1 0 3 0x80 netio pflogd 20987 101152 65777 73 3 0x100090 kqread syslogd 65777 423718 1 0 3 0x100082 netio syslogd 35106 333629 1 77 3 0x100090 poll dhclient 87123 516359 1 0 3 0x80 poll dhclient 30483 478314 0 0 3 0x14200 bored smr 20276 29032 0 0 3 0x14200 pgzero zerothread 54606 500900 0 0 3 0x14200 aiodoned aiodoned 58387 522888 0 0 3 0x14200 syncer update 57581 253212 0 0 3 0x14200 cleaner cleaner 30480 343562 0 0 3 0x14200 reaper reaper 26994 286882 0 0 3 0x14200 pgdaemon pagedaemon 64477 371139 0 0 3 0x14200 bored crynlk 23755 280083 0 0 3 0x14200 bored crypto 60736 323069 0 0 3 0x14200 bored viomb 63821 437214 0 0 3 0x40014200 acpi0 acpi0 43027 360379 0 0 3 0x40014200 idle1 77828 295513 0 0 3 0x14200 bored softnet 12014 129636 0 0 3 0x14200 bored systqmp 95065 28620 0 0 3 0x14200 bored systq 98917 399516 0 0 3 0x40014200 bored softclock 79782 447555 0 0 3 0x40014200 idle0 1 369280 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 33420 (syz-executor.0) thread 0xffff800021272538 (475090) 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 __mp_acquire_count+0x4c sys/kern/kern_lock.c:227 #2 mi_switch+0x390 sys/kern/sched_bsd.c:433 #3 sleep_finish+0x111 sys/kern/kern_synch.c:418 #4 sleep_finish_all+0x32 sleep_finish_timeout sys/kern/kern_synch.c:448 [inline] #4 sleep_finish_all+0x32 sys/kern/kern_synch.c:393 #5 tsleep+0x1bc sys/kern/kern_synch.c:155 #6 getblk+0x14c sys/kern/vfs_bio.c:1031 #7 bread+0x3a bio_doread sys/kern/vfs_bio.c:436 [inline] #7 bread+0x3a sys/kern/vfs_bio.c:481 #8 ffs_read+0x330 #9 VOP_READ+0xbf sys/kern/vfs_vops.c:253 #10 uvn_io+0x2fa #11 uvn_get+0x473 sys/uvm/uvm_vnode.c:1083 #12 uvm_fault+0xa41 sys/uvm/uvm_fault.c:1073 #13 kpageflttrap+0x202 sys/arch/amd64/amd64/trap.c:265 #14 kerntrap+0xef sys/arch/amd64/amd64/trap.c:321 #15 alltraps_kern_meltdown+0x7b #16 copyin+0x53 #17 sys_connect+0x9b sys/kern/uipc_syscalls.c:362 #18 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #18 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9482 6415K 6932K 78643K 10755 0 pcb 13 8K 8K 78643K 24 0 rtable 105 3K 3K 78643K 255 0 ifaddr 44 10K 10K 78643K 52 0 counters 43 33K 33K 78643K 45 0 ioctlops 0 0K 4K 78643K 1470 0 mount 1 1K 1K 78643K 1 0 vnodes 1219 77K 77K 78643K 1278 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 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1825 197K 290K 78643K 13109 0 file desc 6 17K 25K 78643K 198 0 proc 59 63K 95K 78643K 487 0 subproc 32 2K 2K 78643K 51 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 33 2K 2K 78643K 44 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 410 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 93 21K 23K 78643K 1203 0 UVM aobj 3 2K 2K 78643K 3 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 8 0K 0K 78643K 13 0 temp 107 3961K 4025K 78643K 4502 0 kqueue 3 4K 4K 78643K 3 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 arp 64 8 0 2 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 120 29 0 27 1 0 1 1 0 8 0 rtentry 112 56 0 12 2 0 2 2 0 8 0 unpcb 120 29 0 19 1 0 1 1 0 8 0 syncache 296 4 0 4 1 1 0 1 0 8 0 tcpqe 32 63 0 63 2 2 0 1 0 8 0 tcpcb 736 11 0 4 1 0 1 1 0 8 0 inpcb 296 90 0 80 1 0 1 1 0 8 0 nd6 48 9 0 3 1 0 1 1 0 8 0 kcovpl 48 3 0 1 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 pfstitem 24 14 0 5 1 0 1 1 0 8 0 pfstkey 112 14 0 5 1 0 1 1 0 8 0 pfstate 328 14 0 5 2 0 2 2 0 8 0 pfrule 1360 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 256 233 0 44 12 0 12 12 0 8 0 art_table 32 234 0 44 2 0 2 2 0 8 0 art_node 16 55 0 15 1 0 1 1 0 8 0 sysvmsgpl 40 20 0 20 1 0 1 1 0 8 1 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1580 0 173 88 0 88 88 0 8 0 ffsino 272 1580 0 173 94 0 94 94 0 8 0 nchpl 144 2010 0 416 60 0 60 60 0 8 0 uvmvnodes 72 1680 0 0 31 0 31 31 0 8 0 vnodes 208 1680 0 0 89 0 89 89 0 8 0 namei 1024 5142 0 5142 1 0 1 1 0 8 1 percpumem 16 33 0 1 1 0 1 1 0 8 0 scxspl 216 5996 0 5996 9 8 1 8 0 8 1 plimitpl 152 26 0 18 1 0 1 1 0 8 0 sigapl 424 411 0 378 4 0 4 4 0 8 0 futexpl 56 1201 0 1200 1 0 1 1 0 8 0 knotepl 112 74 0 54 1 0 1 1 0 8 0 kqueuepl 152 59 0 57 1 0 1 1 0 8 0 pipepl 304 80 0 69 1 0 1 1 0 8 0 fdescpl 496 395 0 378 3 0 3 3 0 8 0 filepl 152 1476 0 1371 5 0 5 5 0 8 0 lockfpl 104 35 0 34 1 0 1 1 0 8 0 lockfspl 48 17 0 16 1 0 1 1 0 8 0 sessionpl 144 19 0 8 1 0 1 1 0 8 0 pgrppl 48 19 0 8 1 0 1 1 0 8 0 ucredpl 96 81 0 72 1 0 1 1 0 8 0 zombiepl 144 378 0 378 1 0 1 1 0 8 1 processpl 1056 411 0 378 3 0 3 3 0 8 0 procpl 656 625 0 583 4 0 4 4 0 8 0 sockpl 400 148 0 126 3 0 3 3 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 155 0 0 19 0 19 19 0 8 0 mtagpl 96 23 0 0 1 0 1 1 0 8 0 mbufpl 256 244 0 0 15 0 15 15 0 8 0 bufpl 280 3729 0 181 254 0 254 254 0 8 0 anonpl 16 97347 0 93141 52 11 41 51 0 124 12 amapchunkpl 152 2001 0 1859 8 1 7 8 0 158 0 amappl16 192 4087 0 3948 33 14 19 31 0 8 7 amappl15 184 3 0 1 1 0 1 1 0 8 0 amappl14 176 25 0 19 1 0 1 1 0 8 0 amappl13 168 33 0 30 1 0 1 1 0 8 0 amappl12 160 6 0 3 1 0 1 1 0 8 0 amappl11 152 66 0 49 1 0 1 1 0 8 0 amappl10 144 80 0 78 1 0 1 1 0 8 0 amappl9 136 93 0 91 1 0 1 1 0 8 0 amappl8 128 137 0 106 2 0 2 2 0 8 0 amappl7 120 338 0 330 1 0 1 1 0 8 0 amappl6 112 142 0 129 1 0 1 1 0 8 0 amappl5 104 1239 0 1220 1 0 1 1 0 8 0 amappl4 96 284 0 258 1 0 1 1 0 8 0 amappl3 88 131 0 123 1 0 1 1 0 8 0 amappl2 80 2100 0 2025 3 0 3 3 0 8 0 amappl1 72 20514 0 20003 25 14 11 19 0 8 1 amappl 80 911 0 860 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 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 395 0 378 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 395 0 378 1 0 1 1 0 8 0 vmmpekpl 168 6824 0 6800 2 0 2 2 0 8 0 vmmpepl 168 59414 0 57961 94 18 76 85 0 357 12 vmsppl 368 394 0 378 2 0 2 2 0 8 0 pdppl 4096 797 0 756 57 16 41 45 0 8 0 pvpl 32 248023 0 240591 133 11 122 132 0 265 42 pmappl 232 394 0 378 2 1 1 2 0 8 0 extentpl 40 57 0 39 1 0 1 1 0 8 0 phpool 112 303 0 19 9 0 9 9 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff8272eff0) 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 __mp_lock(ffffffff828ce870) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff828ce870) at __mp_lock+0x122 sys/kern/kern_lock.c:147 intr_handler(ffff800022cb7170,ffff80000065a300) at intr_handler+0x5e sys/arch/amd64/amd64/intr.c:532 Xintr_ioapic_edge4_untramp() at Xintr_ioapic_edge4_untramp+0x19f __mp_lock(ffffffff828ce870) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff828ce870) at __mp_lock+0x122 sys/kern/kern_lock.c:147 softintr_dispatch(0) at softintr_dispatch+0x4e sys/arch/amd64/amd64/softintr.c:90 Xsoftclock() at Xsoftclock+0x1f __mp_lock(ffffffff828ce870) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff828ce870) at __mp_lock+0x122 sys/kern/kern_lock.c:147 upageflttrap(ffff800022cb7470,70eeb343000) at upageflttrap+0x77 sys/arch/amd64/amd64/trap.c:180 usertrap(ffff800022cb7470) at usertrap+0x21a sys/arch/amd64/amd64/trap.c:406 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7ffffe0170, count: -13 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:398 witness_checkorder(fffffd807d7c15e8,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd807d7c15e8,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd807d7c15d8,1) at rw_enter+0xd4 rrw_enter(fffffd807d7c15d8,1) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd80704e3018,2001) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 vn_lock(fffffd80704e3018,2001) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 vget(fffffd80704e3018,2001) at vget+0x1c6 sys/kern/vfs_subr.c:671 ktrwriteraw(ffff800021272538,fffffd80704e3018,fffffd807f7b7960,ffff800022cb1ca0,ffff800022cb1c80) at ktrwriteraw+0x138 sys/kern/kern_ktrace.c:659 ktrstruct(ffff800021272538,ffffffff823afafa,fffffd807d62d320,10) at ktrstruct+0x169 ktrwrite2 sys/kern/kern_ktrace.c:627 [inline] ktrstruct(ffff800021272538,ffffffff823afafa,fffffd807d62d320,10) at ktrstruct+0x169 sys/kern/kern_ktrace.c:311 sys_connect(ffff800021272538,ffff800022cb1de8,ffff800022cb1e30) at sys_connect+0x246 syscall(ffff800022cb1eb0) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800022cb1eb0) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:590 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5c778b68670, count: -12