witness: lock order reversal: 1st 0xfffffd807effe2f8 vmmaplk (&map->lock) 2nd 0xfffffd8056c4bc48 inode (&ip->i_lock) lock order "&ip->i_lock"(rrwlock) -> "&map->lock"(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_read+0x66 sys/kern/kern_rwlock.c:111 #2 uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1438 #3 uvm_fault+0x7e sys/uvm/uvm_fault.c:526 #4 pageflttrap+0x254 sys/arch/amd64/amd64/trap.c:219 #5 kerntrap+0xf1 sys/arch/amd64/amd64/trap.c:301 #6 alltraps_kern_meltdown+0x7b #7 copyout+0x53 #8 ffs_read+0x3e2 sys/ufs/ffs/ffs_vnops.c:258 #9 VOP_READ+0xbf sys/kern/vfs_vops.c:247 #10 vn_rdwr+0x10b #11 vmcmd_map_readvn+0xda sys/kern/exec_subr.c:246 #12 exec_process_vmcmds+0xb2 sys/kern/exec_subr.c:143 #13 sys_execve+0x9ff sys/kern/kern_exec.c:461 #14 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #14 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:567 #15 Xsyscall+0x128 lock order "&map->lock"(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:603 #4 vn_lock+0x6c sys/kern/vfs_vnops.c:575 #5 uvn_io+0x2b5 sys/uvm/uvm_vnode.c:1196 #6 uvn_get+0x226 sys/uvm/uvm_vnode.c:1056 #7 uvm_fault+0x1197 sys/uvm/uvm_fault.c:1016 #8 uvm_fault_wire+0x63 sys/uvm/uvm_fault.c:1285 #9 uvm_map_pageable_wire+0x30d sys/uvm/uvm_map.c:2367 #10 sys_mlock+0x180 sys/uvm/uvm_mmap.c:767 #11 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #11 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:567 #12 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(fffffd8056c4bc48,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd8056c4bc48,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd8056c4bc38,81) at rw_enter+0xd4 rrw_enter(fffffd8056c4bc38,81) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd80627da8f8,81) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:603 vn_lock(fffffd80627da8f8,81) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 uvn_io(fffffd8063148768,ffff8000257148c8,1,2,0) at uvn_io+0x2b5 sys/uvm/uvm_vnode.c:1196 uvn_get(fffffd8063148768,0,ffff800025714b20,ffff800025714abc,0,5) at uvn_get+0x226 sys/uvm/uvm_vnode.c:1056 uvm_fault(fffffd807effe2e0,20000000,2,5) at uvm_fault+0x1197 sys/uvm/uvm_fault.c:1016 uvm_fault_wire(fffffd807effe2e0,20000000,20001000,5) at uvm_fault_wire+0x63 sys/uvm/uvm_fault.c:1285 uvm_map_pageable_wire(fffffd807effe2e0,fffffd80569c32b0,fffffd80569c3748,118,0,0) at uvm_map_pageable_wire+0x30d sys/uvm/uvm_map.c:2367 sys_mlock(ffff8000ffffa018,ffff800025714d08,ffff800025714d50) at sys_mlock+0x180 sys/uvm/uvm_mmap.c:767 syscall(ffff800025714dd0) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800025714dd0) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:567 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xadf0d377c80, count: -14 ddb{0}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be68 rbp 0xffff800025714520 rbx 0x3 rdx 0xffff800000af4280 rcx 0x3 rax 0x3ffff acpi_pdirpa+0x2be67 r8 0xffffffff817bbdb3 witness_checkorder+0xf33 r9 0x5 r10 0x97563571b858b7a6 r11 0x8db93916569a2f0 r12 0xffffffff8281e680 w_lodata+0x54590 r13 0 r14 0xffffffff8280aaf0 w_lodata+0x40a00 r15 0xfffffd8002c8f480 rip 0xffffffff82136818 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800025714510 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=513633 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffa508,0xffffffff8288a3c8 process=0xffff8000ffff8fc8 user=0xffff80002570f000, vmspace=0xfffffd807effe2e0 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 17534 117696 43367 32767 2 0x10 syz-executor.1 *17534 513633 43367 32767 7 0x4000010 syz-executor.1 88395 279293 20799 32767 7 0x10 syz-executor.0 88395 94089 20799 32767 2 0x4000010 syz-executor.0 60618 450519 0 0 3 0x14200 bored sosplice 43367 480926 52648 32767 3 0x90 nanosleep syz-executor.1 20799 486688 4971 32767 3 0x90 nanosleep syz-executor.0 52648 119162 52171 0 3 0x82 wait syz-executor.1 4971 220948 52171 0 3 0x82 wait syz-executor.0 52171 125041 85406 0 3 0x82 thrsleep syz-fuzzer 52171 310118 85406 0 3 0x4000082 nanosleep syz-fuzzer 52171 248071 85406 0 3 0x4000082 kqread syz-fuzzer 52171 135301 85406 0 3 0x4000082 thrsleep syz-fuzzer 52171 87348 85406 0 3 0x4000082 thrsleep syz-fuzzer 52171 130906 85406 0 3 0x4000082 thrsleep syz-fuzzer 52171 230721 85406 0 3 0x4000082 thrsleep syz-fuzzer 52171 12393 85406 0 3 0x4000082 thrsleep syz-fuzzer 85406 444059 97988 0 3 0x10008a pause ksh 97988 69345 85069 0 3 0x92 select sshd 26906 164897 1 0 3 0x100083 ttyin getty 85069 234985 1 0 3 0x80 select sshd 22938 79240 36717 73 3 0x100090 kqread syslogd 36717 205546 1 0 3 0x100082 netio syslogd 65763 367115 1 77 3 0x100090 poll dhclient 53716 344389 1 0 3 0x80 poll dhclient 21700 413022 0 0 3 0x14200 bored smr 8514 189934 0 0 2 0x14200 zerothread 28049 503861 0 0 3 0x14200 aiodoned aiodoned 95007 279057 0 0 3 0x14200 syncer update 26828 136649 0 0 3 0x14200 cleaner cleaner 53946 481821 0 0 3 0x14200 reaper reaper 7946 91645 0 0 3 0x14200 pgdaemon pagedaemon 32354 267123 0 0 3 0x14200 bored crynlk 21468 311542 0 0 3 0x14200 bored crypto 65515 74681 0 0 3 0x40014200 acpi0 acpi0 54468 127493 0 0 3 0x40014200 idle1 4550 285502 0 0 3 0x14200 bored softnet 49861 213276 0 0 3 0x14200 bored systqmp 59832 285599 0 0 3 0x14200 bored systq 60444 25798 0 0 3 0x40014200 bored softclock 33077 97721 0 0 3 0x40014200 idle0 1 407345 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 17534 (syz-executor.1) thread 0xffff8000ffffa018 (513633) shared rwlock vmmaplk r = 0 (0xfffffd807effe2f8) #0 witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4b0 sys/kern/subr_witness.c:1164 #1 rw_enter+0x446 sys/kern/kern_rwlock.c:311 #2 vm_map_lock_ln+0xda sys/uvm/uvm_map.c:5452 #3 uvm_map_pageable+0x120 sys/uvm/uvm_map.c:2463 #4 sys_mlock+0x180 sys/uvm/uvm_mmap.c:767 #5 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #5 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:567 #6 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8288d110) #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:567 #2 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9465 6330K 6330K 78643K 10557 0 pcb 13 8K 8K 78643K 13 0 rtable 105 3K 3K 78643K 189 0 ifaddr 39 10K 10K 78643K 39 0 counters 43 33K 33K 78643K 43 0 ioctlops 0 0K 2K 78643K 1120 0 iov 0 0K 16K 78643K 31 0 mount 1 1K 1K 78643K 1 0 vnodes 1216 76K 76K 78643K 1221 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 12 1K 1K 78643K 24 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 8 25K 33K 78643K 55384 0 sigio 0 0K 0K 78643K 27 0 proc 48 50K 83K 78643K 412 0 subproc 34 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 2037 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 43 201K 201K 78643K 43 0 exec 0 0K 2K 78643K 336 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 592 68K 69K 78643K 128608 0 UVM aobj 31 2K 2K 78643K 234 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 4 0 NDP 5 0K 0K 78643K 9 0 temp 101 3961K 4025K 78643K 112655 0 kqueue 3 4K 6K 78643K 18 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 6 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 96 23 0 21 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 41872 0 41864 1 0 1 1 0 8 0 syncache 272 4 0 4 1 1 0 1 0 8 0 tcpqe 32 157 0 157 2 2 0 2 0 8 0 tcpcb 592 4022 0 4018 12 11 1 4 0 8 0 inpcb 296 4063 0 4056 1 0 1 1 0 8 0 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 256 187 0 0 12 0 12 12 0 8 0 art_table 32 188 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 4 2 1 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 14 0 4 1 0 1 1 0 8 0 shmpl 112 231 0 203 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 72705 0 71308 88 0 88 88 0 8 0 ffsino 272 72705 0 71308 94 0 94 94 0 8 0 nchpl 144 151198 0 149600 60 0 60 60 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 208 5926 0 0 312 0 312 312 0 8 0 namei 1024 313354 0 313354 3 2 1 1 0 8 1 percpumem 16 32 0 0 1 0 1 1 0 8 0 scxspl 192 394925 0 394925 10 9 1 7 0 8 1 plimitpl 152 25 0 16 1 0 1 1 0 8 0 sigapl 424 55572 0 55539 4 0 4 4 0 8 0 futexpl 56 382092 0 382092 2 1 1 1 0 8 1 knotepl 112 82 0 62 1 0 1 1 0 8 0 kqueuepl 152 61145 0 61140 1 0 1 1 0 8 0 pipepl 304 24095 0 24084 15 13 2 2 0 8 1 fdescpl 496 55556 0 55539 4 1 3 3 0 8 0 filepl 152 263799 0 263699 8 3 5 5 0 8 1 lockfpl 104 399 0 398 1 0 1 1 0 8 0 lockfspl 48 187 0 186 1 0 1 1 0 8 0 sessionpl 120 17 0 7 1 0 1 1 0 8 0 pgrppl 48 23 0 13 1 0 1 1 0 8 0 ucredpl 96 9141 0 9132 1 0 1 1 0 8 0 zombiepl 144 55539 0 55539 2 1 1 1 0 8 1 processpl 1008 55572 0 55539 5 0 5 5 0 8 0 procpl 632 114216 0 114174 6 2 4 5 0 8 0 sosppl 144 2 0 2 1 1 0 1 0 8 0 sockpl 400 45976 0 45959 20 17 3 3 0 8 1 mcl64k 65536 18 0 0 3 0 3 3 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 0 mcl12k 12288 33 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 25 0 0 3 0 3 3 0 8 0 mcl4k 4096 26 0 0 3 0 3 3 0 8 0 mcl2k2 2112 26 0 0 2 0 2 2 0 8 0 mcl2k 2048 413 0 0 45 20 25 45 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 959 0 0 25 1 24 25 0 8 0 bufpl 280 61949 0 55701 447 0 447 447 0 8 0 anonpl 16 3392206 0 3311369 391 2 389 389 0 124 0 amapchunkpl 152 178314 0 175010 149 2 147 149 0 158 0 amappl16 192 96444 0 94163 127 12 115 127 0 8 0 amappl15 184 27873 0 27869 1 0 1 1 0 8 0 amappl14 176 27501 0 27496 1 0 1 1 0 8 0 amappl13 168 508 0 505 1 0 1 1 0 8 0 amappl12 160 12 0 9 3 2 1 1 0 8 0 amappl11 152 46 0 37 1 0 1 1 0 8 0 amappl10 144 6 0 1 1 0 1 1 0 8 0 amappl9 136 364 0 363 2 1 1 1 0 8 0 amappl8 128 172 0 113 2 0 2 2 0 8 0 amappl7 120 218 0 208 1 0 1 1 0 8 0 amappl6 112 58 0 48 1 0 1 1 0 8 0 amappl5 104 57183 0 57164 1 0 1 1 0 8 0 amappl4 96 314 0 287 1 0 1 1 0 8 0 amappl3 88 4695 0 4687 1 0 1 1 0 8 0 amappl2 80 415867 0 415798 2 0 2 2 0 8 0 amappl1 72 1743794 0 1743289 38 27 11 18 0 8 1 amappl 80 114903 0 114388 11 0 11 11 0 84 0 dma4096 4096 1 0 1 1 1 0 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 64 233 0 203 1 0 1 1 0 8 0 uaddrrnd 24 55556 0 55539 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 55556 0 55539 1 0 1 1 0 8 0 vmmpekpl 168 267962 0 267933 3 1 2 2 0 8 0 vmmpepl 168 7206171 0 7201990 338 154 184 281 0 357 2 vmsppl 368 55555 0 55539 2 0 2 2 0 8 0 pdppl 4096 111119 0 111078 7 1 6 6 0 8 0 pvpl 32 15057178 0 14973062 803 3 800 803 0 265 0 pmappl 232 55555 0 55539 2 1 1 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 315 0 44 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(fffffd8056c4bc48,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd8056c4bc48,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd8056c4bc38,81) at rw_enter+0xd4 rrw_enter(fffffd8056c4bc38,81) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd80627da8f8,81) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:603 vn_lock(fffffd80627da8f8,81) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 uvn_io(fffffd8063148768,ffff8000257148c8,1,2,0) at uvn_io+0x2b5 sys/uvm/uvm_vnode.c:1196 uvn_get(fffffd8063148768,0,ffff800025714b20,ffff800025714abc,0,5) at uvn_get+0x226 sys/uvm/uvm_vnode.c:1056 uvm_fault(fffffd807effe2e0,20000000,2,5) at uvm_fault+0x1197 sys/uvm/uvm_fault.c:1016 uvm_fault_wire(fffffd807effe2e0,20000000,20001000,5) at uvm_fault_wire+0x63 sys/uvm/uvm_fault.c:1285 uvm_map_pageable_wire(fffffd807effe2e0,fffffd80569c32b0,fffffd80569c3748,118,0,0) at uvm_map_pageable_wire+0x30d sys/uvm/uvm_map.c:2367 sys_mlock(ffff8000ffffa018,ffff800025714d08,ffff800025714d50) at sys_mlock+0x180 sys/uvm/uvm_mmap.c:767 syscall(ffff800025714dd0) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800025714dd0) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:567 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xadf0d377c80, count: -14 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800020d80ff0) 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(ffffffff8288cf08) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff8288cf08) at __mp_lock+0x122 sys/kern/kern_lock.c:147 pageflttrap(ffff800024902ca0,9ad2b77eee8,1) at pageflttrap+0x70 sys/arch/amd64/amd64/trap.c:178 usertrap(ffff800024902ca0) at usertrap+0x210 sys/arch/amd64/amd64/trap.c:383 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7ffffe9ab0, count: -7