login: witness: lock order reversal: 1st 0xffffffff8290fe50 netlock (netlock) 2nd 0xfffffd806cdb3bb0 vmmaplk (&map->lock) lock order "&map->lock"(rwlock) -> "netlock"(rwlock) first seen at: #0 rw_enter_write+0x5b sys/kern/kern_rwlock.c:128 #1 udp_sysctl+0x8a sys/netinet/udp_usrreq.c:1269 #2 sys_sysctl+0x209 sys/kern/kern_sysctl.c:249 #3 syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] #3 syscall+0x489 sys/arch/amd64/amd64/trap.c:585 #4 Xsyscall+0x128 lock order "netlock"(rwlock) -> "&map->lock"(rwlock) first seen at: #0 rw_enter_read+0x66 sys/kern/kern_rwlock.c:112 #1 uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1758 #2 uvm_fault_check+0x3a sys/uvm/uvm_fault.c:674 #3 uvm_fault+0x102 sys/uvm/uvm_fault.c:602 #4 kpageflttrap+0x209 #5 kerntrap+0xef sys/arch/amd64/amd64/trap.c:318 #6 alltraps_kern_meltdown+0x7b #7 copyout+0x53 #8 ifioctl_get+0x2dd #9 soo_ioctl+0x26c #10 sys_ioctl+0x4a2 #11 syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] #11 syscall+0x489 sys/arch/amd64/amd64/trap.c:585 #12 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:440 witness_checkorder(fffffd806cdb3bb0,1,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2502 [inline] witness_checkorder(fffffd806cdb3bb0,1,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1105 rw_enter_read(fffffd806cdb3ba0) at rw_enter_read+0x66 sys/kern/kern_rwlock.c:112 uvmfault_lookup(ffff80002e3bd880,0) at uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1758 uvm_fault_check(ffff80002e3bd880,ffff80002e3bd8b8,ffff80002e3bd8e0) at uvm_fault_check+0x3a sys/uvm/uvm_fault.c:674 uvm_fault(fffffd806cdb3b98,20000000,0,2) at uvm_fault+0x102 sys/uvm/uvm_fault.c:602 kpageflttrap(ffff80002e3bda10,20000300) at kpageflttrap+0x209 kerntrap(ffff80002e3bda10) at kerntrap+0xef sys/arch/amd64/amd64/trap.c:318 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b copyout() at copyout+0x53 ifioctl_get(c0106924,ffff80002e3bdcc0) at ifioctl_get+0x2dd soo_ioctl(fffffd8068d6c318,c0106924,ffff80002e3bdcc0,ffff80002c9657a8) at soo_ioctl+0x26c sys_ioctl(ffff80002c9657a8,ffff80002e3bddd8,ffff80002e3bde30) at sys_ioctl+0x4a2 syscall(ffff80002e3bdea0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff80002e3bdea0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb3bcf76f3d0, count: -15 ddb{1}> show registers rdi 0x3 rsi 0xffffffff8294abb0 __sancov_gen_cov_switch_values.134 rbp 0xffff80002e3bd570 rbx 0x3 rdx 0 rcx 0 rax 0xffff80002c9657a8 r8 0xffff80002e3bd4e0 r9 0x8080808080808080 r10 0xb3f95caca9cb97ec r11 0xc898960b8c75413d r12 0xffffffff82aafd50 w_lodata+0x523e0 r13 0 r14 0xffffffff82aa5c70 w_lodata+0x48300 r15 0xfffffd8002f62d80 rip 0xffffffff8138d658 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002e3bd560 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.4) pid=166084 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=82, nice=20 forw=0xffffffffffffffff, list=0xffff80002c964548,0xffff8000ffff6d40 process=0xffff80002af1b200 user=0xffff80002e3b8000, vmspace=0xfffffd806cdb3b98 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 37490 300910 21019 32767 2 0x10 syz-executor.3 12558 1135 70465 32767 2 0x10 syz-executor.1 12558 47840 70465 32767 3 0x4000090 fsleep syz-executor.1 63617 276664 70602 32767 2 0x10 syz-executor.4 63617 505943 70602 32767 3 0x4000090 fsleep syz-executor.4 63617 334671 70602 32767 2 0x4000010 syz-executor.4 *63617 166084 70602 32767 7 0x4000010 syz-executor.4 63617 88810 70602 32767 3 0x4000010 vmmaplk syz-executor.4 11607 69235 74848 32767 2 0x10 syz-executor.0 11607 291752 74848 32767 3 0x4000090 fsleep syz-executor.0 75762 288875 41682 32767 2 0x10 syz-executor.2 75762 284235 41682 32767 3 0x4000090 fsleep syz-executor.2 57330 112659 56957 32767 2 0x10 syz-executor.6 78158 30719 46938 32767 7 0x10 syz-executor.5 78158 240381 46938 32767 2 0x4000010 syz-executor.5 78158 357436 46938 32767 3 0x4000090 fsleep syz-executor.5 78158 146637 46938 32767 2 0x4000010 syz-executor.5 30219 364566 30605 32767 2 0x10 syz-executor.7 30219 218708 30605 32767 3 0x4000090 fsleep syz-executor.7 30219 306332 30605 32767 3 0x4000090 fsleep syz-executor.7 52958 515890 0 0 3 0x14200 bored sosplice 30605 165728 53881 32767 3 0x90 nanoslp syz-executor.7 53881 272475 64267 0 3 0x82 wait syz-executor.7 56957 108123 52563 32767 3 0x90 nanoslp syz-executor.6 46938 316291 18666 32767 3 0x90 nanoslp syz-executor.5 70602 227423 61577 32767 3 0x90 nanoslp syz-executor.4 21019 515433 34912 32767 3 0x90 nanoslp syz-executor.3 52563 502875 64267 0 3 0x82 wait syz-executor.6 18666 151462 64267 0 3 0x82 wait syz-executor.5 61577 108602 64267 0 3 0x82 wait syz-executor.4 41682 439506 7002 32767 3 0x90 nanoslp syz-executor.2 34912 24225 64267 0 3 0x82 wait syz-executor.3 70465 214012 59813 32767 3 0x90 nanoslp syz-executor.1 7002 77071 64267 0 3 0x82 wait syz-executor.2 74848 311619 74157 32767 3 0x90 nanoslp syz-executor.0 59813 361130 64267 0 3 0x82 wait syz-executor.1 74157 281075 64267 0 3 0x82 wait syz-executor.0 64267 387471 57623 0 3 0x82 thrsleep syz-fuzzer 64267 55134 57623 0 3 0x4000082 nanoslp syz-fuzzer 64267 81304 57623 0 3 0x4000082 thrsleep syz-fuzzer 64267 176374 57623 0 3 0x4000082 thrsleep syz-fuzzer 64267 202482 57623 0 3 0x4000082 thrsleep syz-fuzzer 64267 408816 57623 0 3 0x4000082 thrsleep syz-fuzzer 64267 436651 57623 0 3 0x4000082 kqread syz-fuzzer 64267 185456 57623 0 3 0x4000082 thrsleep syz-fuzzer 64267 472600 57623 0 3 0x4000082 thrsleep syz-fuzzer 57623 48405 69031 0 3 0x10008a sigsusp ksh 69031 270088 93729 0 3 0x9a kqread sshd 94775 181746 1 0 3 0x100083 ttyin getty 93729 49335 1 0 3 0x88 kqread sshd 67720 449757 96929 73 3 0x1100090 kqread syslogd 96929 364524 1 0 3 0x100082 netio syslogd 33946 205854 1 0 3 0x100080 kqread resolvd 74404 406781 84665 77 3 0x100092 kqread dhcpleased 5219 214004 84665 77 3 0x100092 kqread dhcpleased 84665 8575 1 0 3 0x80 kqread dhcpleased 48599 25259 0 0 3 0x14200 bored smr 86649 110393 0 0 2 0x14200 zerothread 61575 445648 0 0 3 0x14200 aiodoned aiodoned 63264 55312 0 0 3 0x14200 syncer update 13517 253587 0 0 3 0x14200 cleaner cleaner 34764 522414 0 0 3 0x14200 reaper reaper 51873 310499 0 0 3 0x14200 pgdaemon pagedaemon 46870 500426 0 0 3 0x14200 bored viomb 84823 399525 0 0 3 0x40014200 acpi0 acpi0 22602 117658 0 0 3 0x40014200 idle1 18868 55233 0 0 3 0x14200 bored softnet 60339 471470 0 0 3 0x14200 bored systqmp 3599 238486 0 0 3 0x14200 bored systq 33124 158191 0 0 3 0x40014200 bored softclock 30884 279206 0 0 3 0x40014200 idle0 1 429158 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 63617 (syz-executor.4) thread 0xffff80002c9657a8 (166084) shared rwlock netlock r = 0 (0xffffffff8290fe50) #0 witness_lock+0x44d #1 ifioctl_get+0x2d5 sys/net/if.c:2319 #2 soo_ioctl+0x26c #3 sys_ioctl+0x4a2 #4 syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] #4 syscall+0x489 sys/arch/amd64/amd64/trap.c:585 #5 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff829de988) #0 witness_lock+0x44d #1 soo_ioctl+0x25a sys/kern/sys_socket.c:136 #2 sys_ioctl+0x4a2 #3 syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] #3 syscall+0x489 sys/arch/amd64/amd64/trap.c:585 #4 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10188 6409K 6419K 78643K 11279 0 pcb 13 12K 14K 78643K 17 0 rtable 254 7K 7K 78643K 456 0 ifaddr 81 16K 16K 78643K 82 0 sysctl 1 1K 1K 78643K 1 0 counters 56 35K 35K 78643K 56 0 ioctlops 0 0K 2K 78643K 72 0 iov 0 0K 28K 78643K 417 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1270 79K 79K 78643K 1534 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 34 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 411 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 26 97K 121K 78643K 2611 0 sigio 0 0K 0K 78643K 102 0 proc 56 74K 111K 78643K 587 0 subproc 104 6K 6K 78643K 104 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 129 0 in_multi 99 6K 6K 78643K 121 0 ether_multi 1 0K 0K 78643K 7 0 mrt 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 145 652K 652K 78643K 145 0 exec 0 0K 2K 78643K 948 0 tdb 3 0K 0K 78643K 3 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 379 89K 105K 78643K 35256 0 UVM aobj 131 9K 9K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 42 0 NDP 11 0K 2K 78643K 27 0 temp 125 4707K 4771K 78643K 9536 0 kqueue 12 18K 24K 78643K 182 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 120 197 0 192 3 2 1 3 0 8 0 rtentry 112 119 0 1 4 0 4 4 0 8 0 unpcb 136 1596 0 1583 21 15 6 9 0 8 5 syncache 296 55 0 55 4 3 1 1 0 8 1 tcpqe 32 386 0 386 3 3 0 1 0 8 0 tcpcb 736 1283 0 1272 35 25 10 14 0 8 8 arp 120 18 0 0 1 0 1 1 0 8 0 ipq 40 1 0 1 1 1 0 1 0 8 0 ipqe 40 4 0 4 1 1 0 1 0 8 0 inpcb 304 4794 0 4778 44 34 10 15 0 8 8 nd6 48 32 0 0 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 534 0 0 34 0 34 34 0 8 0 art_table 32 535 0 0 5 0 5 5 0 8 0 art_node 16 118 0 10 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 6 1 1 0 1 0 8 0 semapl 112 409 0 399 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 4544 0 3115 90 0 90 90 0 8 0 ffsino 272 4544 0 3115 96 0 96 96 0 8 0 nchpl 144 8010 0 6349 62 0 62 62 0 8 0 uvmvnodes 80 4657 0 0 96 0 96 96 0 8 0 vnodes 224 4657 0 0 274 0 274 274 0 8 0 namei 1024 26841 0 26841 2 1 1 2 0 8 1 percpumem 16 40 0 0 1 0 1 1 0 8 0 scxspl 216 27277 0 27277 16 14 2 8 0 8 2 plimitpl 152 333 0 308 2 0 2 2 0 8 0 sigapl 424 2895 0 2843 7 0 7 7 0 8 0 futexpl 64 20290 0 20283 2 1 1 1 0 8 0 knotepl 120 361 0 0 11 1 10 11 0 8 0 kqueuepl 216 765 0 755 22 17 5 8 0 8 4 pipepl 336 334 0 306 6 3 3 6 0 8 0 fdescpl 496 2880 0 2843 7 1 6 6 0 8 0 filepl 152 17126 0 16882 38 21 17 19 0 8 7 lockfpl 104 282 0 280 1 0 1 1 0 8 0 lockfspl 48 92 0 90 1 0 1 1 0 8 0 sessionpl 144 23 0 7 1 0 1 1 0 8 0 pgrppl 48 106 0 90 1 0 1 1 0 8 0 ucredpl 96 1810 0 1792 1 0 1 1 0 8 0 zombiepl 144 2843 0 2843 1 0 1 1 0 8 1 processpl 1064 2895 0 2843 5 1 4 4 0 8 0 procpl 672 7745 0 7673 11 4 7 8 0 8 0 sosppl 168 37 0 37 2 2 0 1 0 8 0 sockpl 480 6684 0 6650 136 124 12 34 0 8 7 mcl64k 65536 15 0 0 2 0 2 2 0 8 0 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 13 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 13 0 0 1 0 1 1 0 8 0 mcl2k 2048 243 0 0 26 0 26 26 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 577 0 0 35 0 35 35 0 8 0 bufpl 288 6815 0 480 453 0 453 453 0 8 0 anonpl 24 790677 0 776167 138 23 115 115 0 186 20 amapchunkpl 152 92643 0 91772 74 28 46 50 0 158 12 amappl16 200 8299 0 7959 47 20 27 31 0 8 8 amappl15 192 405 0 401 1 0 1 1 0 8 0 amappl14 184 345 0 338 1 0 1 1 0 8 0 amappl13 176 83 0 82 1 0 1 1 0 8 0 amappl12 168 955 0 947 2 1 1 1 0 8 0 amappl11 160 353 0 338 1 0 1 1 0 8 0 amappl10 152 676 0 667 1 0 1 1 0 8 0 amappl9 144 466 0 462 1 0 1 1 0 8 0 amappl8 136 978 0 892 4 0 4 4 0 8 0 amappl7 128 413 0 399 1 0 1 1 0 8 0 amappl6 120 207 0 187 2 1 1 2 0 8 0 amappl5 112 2465 0 2438 1 0 1 1 0 8 0 amappl4 104 1475 0 1448 1 0 1 1 0 8 0 amappl3 96 1263 0 1242 1 0 1 1 0 8 0 amappl2 88 1274 0 1225 3 1 2 3 0 8 0 amappl1 80 54176 0 53515 21 6 15 18 0 8 0 amappl 88 34669 0 34388 7 0 7 7 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 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 2880 0 2843 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2880 0 2843 1 0 1 1 0 8 0 vmmpekpl 168 24566 0 24512 3 0 3 3 0 8 0 vmmpepl 168 263066 0 260291 152 18 134 134 0 357 12 vmsppl 368 2879 0 2843 4 0 4 4 0 8 0 rwobjpl 56 70281 0 64148 90 0 90 90 0 8 0 pdppl 4096 5767 0 5686 137 56 81 93 0 8 0 pvpl 32 1375498 0 1355576 280 78 202 243 0 265 34 pmappl 248 2879 0 2843 4 1 3 3 0 8 0 extentpl 40 58 0 38 1 0 1 1 0 8 0 phpool 112 934 0 87 25 0 25 25 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff829baff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 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(ffffffff829de780) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff829de780) at __mp_lock+0x122 sys/kern/kern_lock.c:147 intr_handler(ffff8000262e0680,ffff800000077500) at intr_handler+0x5e sys/arch/amd64/amd64/intr.c:532 Xintr_ioapic_edge16_untramp() at Xintr_ioapic_edge16_untramp+0x18f __mp_lock(ffffffff829de780) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff829de780) at __mp_lock+0x122 sys/kern/kern_lock.c:147 softintr_dispatch(0) at softintr_dispatch+0x4e sys/arch/amd64/amd64/softintr.c:88 Xsoftclock() at Xsoftclock+0x1f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x16 kd_curproc sys/dev/kcov.c:574 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x16 sys/dev/kcov.c:148 __mp_lock(ffffffff829de780) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff829de780) at __mp_lock+0x133 sys/kern/kern_lock.c:147 syscall(ffff8000262e09c0) at syscall+0x3ef mi_syscall sys/sys/syscall_mi.h:93 [inline] syscall(ffff8000262e09c0) at syscall+0x3ef sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe47c0, 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:440 witness_checkorder(fffffd806cdb3bb0,1,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2502 [inline] witness_checkorder(fffffd806cdb3bb0,1,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1105 rw_enter_read(fffffd806cdb3ba0) at rw_enter_read+0x66 sys/kern/kern_rwlock.c:112 uvmfault_lookup(ffff80002e3bd880,0) at uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1758 uvm_fault_check(ffff80002e3bd880,ffff80002e3bd8b8,ffff80002e3bd8e0) at uvm_fault_check+0x3a sys/uvm/uvm_fault.c:674 uvm_fault(fffffd806cdb3b98,20000000,0,2) at uvm_fault+0x102 sys/uvm/uvm_fault.c:602 kpageflttrap(ffff80002e3bda10,20000300) at kpageflttrap+0x209 kerntrap(ffff80002e3bda10) at kerntrap+0xef sys/arch/amd64/amd64/trap.c:318 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b copyout() at copyout+0x53 ifioctl_get(c0106924,ffff80002e3bdcc0) at ifioctl_get+0x2dd soo_ioctl(fffffd8068d6c318,c0106924,ffff80002e3bdcc0,ffff80002c9657a8) at soo_ioctl+0x26c sys_ioctl(ffff80002c9657a8,ffff80002e3bddd8,ffff80002e3bde30) at sys_ioctl+0x4a2 syscall(ffff80002e3bdea0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff80002e3bdea0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb3bcf76f3d0, count: -15