witness: lock order reversal: 1st 0xfffffd807effb8b8 vmmaplk (&map->lock) 2nd 0xfffffd80640874e0 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+0x24f sys/arch/amd64/amd64/trap.c:219 #5 kerntrap+0xf1 sys/arch/amd64/amd64/trap.c:300 #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:253 #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:566 #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:614 #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:772 #11 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #11 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:566 #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(fffffd80640874e0,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd80640874e0,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd80640874d0,81) at rw_enter+0xd4 rrw_enter(fffffd80640874d0,81) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd8062a30c48,81) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 vn_lock(fffffd8062a30c48,81) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 uvn_io(fffffd80625b28d0,ffff80002210c118,1,2,0) at uvn_io+0x2b5 sys/uvm/uvm_vnode.c:1196 uvn_get(fffffd80625b28d0,0,ffff80002210c370,ffff80002210c30c,0,1) at uvn_get+0x226 sys/uvm/uvm_vnode.c:1056 uvm_fault(fffffd807effb8a0,20002000,2,1) at uvm_fault+0x1197 sys/uvm/uvm_fault.c:1016 uvm_fault_wire(fffffd807effb8a0,20002000,20003000,1) at uvm_fault_wire+0x63 sys/uvm/uvm_fault.c:1285 uvm_map_pageable_wire(fffffd807effb8a0,fffffd8064072630,fffffd80640726d8,116,0,0) at uvm_map_pageable_wire+0x30d sys/uvm/uvm_map.c:2367 sys_mlock(ffff8000212ab160,ffff80002210c558,ffff80002210c5a0) at sys_mlock+0x180 sys/uvm/uvm_mmap.c:772 syscall(ffff80002210c620) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff80002210c620) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:566 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb6c4628e460, count: -14 ddb{0}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be68 rbp 0xffff80002210bd70 rbx 0x3 rdx 0xffff800000b0aa40 rcx 0x3 rax 0x3ffff acpi_pdirpa+0x2be67 r8 0xffffffff81a48a13 witness_checkorder+0xf33 r9 0x5 r10 0x2a19a0843810277b r11 0xfebcfe3d1e4f675c r12 0xffffffff8284d180 w_lodata+0x540c0 r13 0 r14 0xffffffff82845a90 w_lodata+0x4c9d0 r15 0xfffffd8002c8c500 rip 0xffffffff81e244e8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002210bd60 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=105009 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000212aa290,0xffff8000212ab3e8 process=0xffff8000212737a8 user=0xffff800022107000, vmspace=0xfffffd807effb8a0 estcpu=4, cpticks=4, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 15981 58451 25277 0 2 0 syz-executor.0 15981 343424 25277 0 3 0x4000080 fsleep syz-executor.0 49567 199164 24882 0 7 0 syz-executor.1 *49567 105009 24882 0 7 0x4000000 syz-executor.1 24882 367722 73257 0 3 0x82 nanosleep syz-executor.1 25277 195850 73257 0 3 0x82 nanosleep syz-executor.0 73257 166539 72783 0 3 0x82 thrsleep syz-fuzzer 73257 150296 72783 0 3 0x4000082 thrsleep syz-fuzzer 73257 119784 72783 0 3 0x4000082 kqread syz-fuzzer 73257 260492 72783 0 3 0x4000082 thrsleep syz-fuzzer 73257 224057 72783 0 3 0x4000082 thrsleep syz-fuzzer 73257 218557 72783 0 3 0x4000082 thrsleep syz-fuzzer 73257 281794 72783 0 3 0x4000082 thrsleep syz-fuzzer 73257 374189 72783 0 3 0x4000082 thrsleep syz-fuzzer 72783 375175 25364 0 3 0x10008a pause ksh 25364 32676 34247 0 3 0x92 select sshd 55866 282885 1 0 3 0x100083 ttyin getty 34247 96096 1 0 3 0x80 select sshd 7630 496247 59913 74 3 0x100092 bpf pflogd 59913 477890 1 0 3 0x80 netio pflogd 41067 308636 90625 73 3 0x100090 kqread syslogd 90625 489199 1 0 3 0x100082 netio syslogd 50620 132356 1 77 3 0x100090 poll dhclient 24160 218690 1 0 3 0x80 poll dhclient 75017 266846 0 0 3 0x14200 bored smr 72710 183445 0 0 2 0x14200 zerothread 78519 105546 0 0 3 0x14200 aiodoned aiodoned 42838 247389 0 0 3 0x14200 syncer update 44836 488773 0 0 3 0x14200 cleaner cleaner 47370 412386 0 0 3 0x14200 reaper reaper 18208 490284 0 0 3 0x14200 pgdaemon pagedaemon 21979 509908 0 0 3 0x14200 bored crynlk 68489 102078 0 0 3 0x14200 bored crypto 12165 28083 0 0 3 0x14200 bored viomb 10584 344094 0 0 3 0x40014200 acpi0 acpi0 71342 35197 0 0 3 0x40014200 idle1 96177 210723 0 0 3 0x14200 bored softnet 92073 404993 0 0 3 0x14200 bored systqmp 18944 301993 0 0 3 0x14200 bored systq 86582 341604 0 0 3 0x40014200 bored softclock 34732 494040 0 0 3 0x40014200 idle0 1 119217 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 49567 (syz-executor.1) thread 0xffff8000212ab160 (105009) shared rwlock vmmaplk r = 0 (0xfffffd807effb8b8) #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:772 #5 syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] #5 syscall+0x4a1 sys/arch/amd64/amd64/trap.c:566 #6 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff828e0120) #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:566 #2 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9484 6416K 6483K 78643K 10608 0 pcb 13 8K 8K 78643K 17 0 rtable 105 3K 3K 78643K 203 0 ifaddr 44 10K 11K 78643K 49 0 counters 43 33K 34K 78643K 45 0 ioctlops 0 0K 4K 78643K 1469 0 iov 0 0K 0K 78643K 1 0 mount 1 1K 1K 78643K 1 0 vnodes 1225 77K 77K 78643K 1238 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 3 0K 0K 78643K 3 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1825 197K 290K 78643K 13109 0 file desc 6 17K 25K 78643K 46 0 proc 59 63K 83K 78643K 447 0 subproc 32 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 37 175K 175K 78643K 37 0 exec 0 0K 2K 78643K 359 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 215 44K 44K 78643K 923 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 6 0K 0K 78643K 11 0 temp 66 3951K 4015K 78643K 2081 0 kqueue 3 4K 4K 78643K 3 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 19 0 17 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 25 0 15 1 0 1 1 0 8 0 syncache 272 4 0 4 1 1 0 1 0 8 0 tcpqe 32 46 0 46 1 1 0 1 0 8 0 tcpcb 592 11 0 6 1 0 1 1 0 8 0 inpcb 296 44 0 36 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 ppxss 1128 1 0 1 1 0 1 1 0 8 1 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 11 0 2 1 0 1 1 0 8 0 pfstkey 112 11 0 2 1 0 1 1 0 8 0 pfstate 328 11 0 2 1 0 1 1 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 256 189 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 semapl 112 1 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1441 0 36 88 0 88 88 0 8 0 ffsino 272 1441 0 36 95 1 94 94 0 8 0 nchpl 144 1673 0 67 60 0 60 60 0 8 0 uvmvnodes 72 1500 0 0 28 0 28 28 0 8 0 vnodes 208 1500 0 0 79 0 79 79 0 8 0 namei 1024 4371 0 4371 2 1 1 1 0 8 1 percpumem 16 33 0 1 1 0 1 1 0 8 0 scxspl 192 5079 0 5079 8 7 1 7 0 8 1 plimitpl 152 15 0 7 1 0 1 1 0 8 0 sigapl 424 262 0 229 4 0 4 4 0 8 0 futexpl 56 167 0 166 1 0 1 1 0 8 0 knotepl 112 62 0 42 1 0 1 1 0 8 0 kqueuepl 152 13 0 10 1 0 1 1 0 8 0 pipepl 304 80 0 69 2 0 2 2 0 8 1 fdescpl 496 246 0 229 3 0 3 3 0 8 0 filepl 152 1178 0 1066 6 1 5 5 0 8 0 lockfpl 104 5 0 4 1 0 1 1 0 8 0 lockfspl 48 3 0 2 1 0 1 1 0 8 0 sessionpl 120 18 0 7 1 0 1 1 0 8 0 pgrppl 48 18 0 7 1 0 1 1 0 8 0 ucredpl 96 68 0 59 1 0 1 1 0 8 0 zombiepl 144 229 0 229 2 1 1 1 0 8 1 processpl 1008 262 0 229 5 0 5 5 0 8 0 procpl 632 288 0 246 4 0 4 4 0 8 0 sockpl 400 88 0 68 4 1 3 3 0 8 1 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 503 0 0 62 0 62 62 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 498 0 0 31 0 31 31 0 8 0 bufpl 280 3507 0 181 238 0 238 238 0 8 0 anonpl 16 60147 0 23896 147 1 146 146 0 124 0 amapchunkpl 152 2423 0 1125 51 1 50 50 0 158 0 amappl16 192 1107 0 135 49 0 49 49 0 8 0 amappl15 184 1 0 1 1 1 0 1 0 8 0 amappl14 176 23 0 19 1 0 1 1 0 8 0 amappl13 168 33 0 29 1 0 1 1 0 8 0 amappl12 160 11 0 8 1 0 1 1 0 8 0 amappl11 152 57 0 41 1 0 1 1 0 8 0 amappl10 144 10 0 7 1 0 1 1 0 8 0 amappl9 136 378 0 373 1 0 1 1 0 8 0 amappl8 128 133 0 103 2 0 2 2 0 8 0 amappl7 120 259 0 249 1 0 1 1 0 8 0 amappl6 112 66 0 56 1 0 1 1 0 8 0 amappl5 104 384 0 365 1 0 1 1 0 8 0 amappl4 96 275 0 250 1 0 1 1 0 8 0 amappl3 88 134 0 124 1 0 1 1 0 8 0 amappl2 80 1062 0 990 3 0 3 3 0 8 0 amappl1 72 16122 0 15613 25 14 11 19 0 8 1 amappl 80 670 0 501 4 0 4 4 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 24 246 0 229 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 246 0 229 1 0 1 1 0 8 0 vmmpekpl 168 6111 0 6074 2 0 2 2 0 8 0 vmmpepl 168 39271 0 36877 152 8 144 144 0 357 39 vmsppl 368 245 0 229 2 0 2 2 0 8 0 pdppl 4096 499 0 458 7 1 6 6 0 8 0 pvpl 32 162742 0 122651 324 0 324 324 0 265 0 pmappl 232 245 0 229 2 0 2 2 0 8 1 extentpl 40 57 0 39 1 0 1 1 0 8 0 phpool 112 315 0 8 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(fffffd80640874e0,9,0) at witness_checkorder+0xf5a witness_debugger sys/kern/subr_witness.c:2490 [inline] witness_checkorder(fffffd80640874e0,9,0) at witness_checkorder+0xf5a sys/kern/subr_witness.c:1087 rw_enter(fffffd80640874d0,81) at rw_enter+0xd4 rrw_enter(fffffd80640874d0,81) at rrw_enter+0x88 sys/kern/kern_rwlock.c:462 VOP_LOCK(fffffd8062a30c48,81) at VOP_LOCK+0x4b sys/kern/vfs_vops.c:614 vn_lock(fffffd8062a30c48,81) at vn_lock+0x6c sys/kern/vfs_vnops.c:575 uvn_io(fffffd80625b28d0,ffff80002210c118,1,2,0) at uvn_io+0x2b5 sys/uvm/uvm_vnode.c:1196 uvn_get(fffffd80625b28d0,0,ffff80002210c370,ffff80002210c30c,0,1) at uvn_get+0x226 sys/uvm/uvm_vnode.c:1056 uvm_fault(fffffd807effb8a0,20002000,2,1) at uvm_fault+0x1197 sys/uvm/uvm_fault.c:1016 uvm_fault_wire(fffffd807effb8a0,20002000,20003000,1) at uvm_fault_wire+0x63 sys/uvm/uvm_fault.c:1285 uvm_map_pageable_wire(fffffd807effb8a0,fffffd8064072630,fffffd80640726d8,116,0,0) at uvm_map_pageable_wire+0x30d sys/uvm/uvm_map.c:2367 sys_mlock(ffff8000212ab160,ffff80002210c558,ffff80002210c5a0) at sys_mlock+0x180 sys/uvm/uvm_mmap.c:772 syscall(ffff80002210c620) at syscall+0x4a1 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff80002210c620) at syscall+0x4a1 sys/arch/amd64/amd64/trap.c:566 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb6c4628e460, 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x19 sys/dev/kcov.c:143 __mp_lock(ffffffff828dff18) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff828dff18) at __mp_lock+0x133 sys/kern/kern_lock.c:147 syscall(ffff80002351abc0) at syscall+0x3fd mi_syscall sys/sys/syscall_mi.h:93 [inline] syscall(ffff80002351abc0) at syscall+0x3fd sys/arch/amd64/amd64/trap.c:566 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffcacb0, count: -7