login: witness: acquiring duplicate lock of same type: "&sc->sc_lock" 1st wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:626 2nd wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:242 Starting stack trace... witness_checkorder(ffff8000019b09d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019b09d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019b09c0,ffffffff81f354ca,f2) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff8000019b0900,ffff8000019a9650) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:243 [inline] wsmux_mux_open(ffff8000019b0900,ffff8000019a9650) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:225 wsmux_attach_sc(ffff8000019a9600,ffff8000019b0900) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:667 VOP_IOCTL(fffffd806e0993d0,80085761,ffff800020c315d0,f,fffffd807f7c79c0,ffff800020b42bd0) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd80691ecb68,80085761,ffff800020c315d0,ffff800020b42bd0) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42bd0,ffff800020c31718,ffff800020c31700) at sys_ioctl+0x646 syscall(ffff800020c317b0) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c317b0) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,317c36fa010) at Xsyscall+0x128 end of kernel end trace frame: 0x31a6db222c0, count: 248 End of stack trace. 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:399 witness_checkorder(ffff8000019b09d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019b09d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019b09c0,ffffffff81f354ca,f2) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff8000019b0900,ffff8000019a9650) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:243 [inline] wsmux_mux_open(ffff8000019b0900,ffff8000019a9650) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:225 wsmux_attach_sc(ffff8000019a9600,ffff8000019b0900) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:667 VOP_IOCTL(fffffd806e0993d0,80085761,ffff800020c315d0,f,fffffd807f7c79c0,ffff800020b42bd0) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd80691ecb68,80085761,ffff800020c315d0,ffff800020b42bd0) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42bd0,ffff800020c31718,ffff800020c31700) at sys_ioctl+0x646 syscall(ffff800020c317b0) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c317b0) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,317c36fa010) at Xsyscall+0x128 end of kernel end trace frame: 0x31a6db222c0, count: -10 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c31200 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b49000 rax 0xffff800001747d40 r8 0xffffffff81316553 kprintf+0x183 r9 0x1 r10 0x25 r11 0xa0f081d252bd064e r12 0xffffffff81f354ca substchar+0x955e r13 0xf2 r14 0xffffffff81f25297 apollo_udma33_tim+0x16e4 r15 0xffffffff81f354ca substchar+0x955e rip 0xffffffff81264218 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c311f0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=116364 stat=onproc flags process=0 proc=4000000 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020b42720,0xffffffff82334d38 process=0xffff800020b45078 user=0xffff800020c2c000, vmspace=0xfffffd807f00d438 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 80135 137365 95181 0 3 0x80 fsleep syz-executor.1 *80135 116364 95181 0 7 0x4000000 syz-executor.1 56558 152166 1 0 3 0x100083 ttyin getty 50933 289988 0 0 3 0x14200 bored sosplice 95181 216826 5830 0 3 0x82 nanosleep syz-executor.1 36406 61729 5830 0 3 0x2 biowait syz-executor.0 5830 253505 37369 0 3 0x82 thrsleep syz-fuzzer 5830 276932 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 395913 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 467202 37369 0 3 0x4000082 kqread syz-fuzzer 5830 401246 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 8206 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 205762 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 228576 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 175849 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 294508 37369 0 3 0x4000082 thrsleep syz-fuzzer 5830 202155 37369 0 3 0x4000082 thrsleep syz-fuzzer 37369 302940 36271 0 3 0x10008a pause ksh 36271 40561 70425 0 3 0x92 select sshd 70425 261607 1 0 3 0x80 select sshd 35508 517049 73505 73 7 0x100090 syslogd 73505 52286 1 0 3 0x100082 netio syslogd 938 519371 1 77 3 0x100090 poll dhclient 16103 261992 1 0 3 0x80 poll dhclient 70895 99202 0 0 3 0x14200 pgzero zerothread 92803 45228 0 0 3 0x14200 aiodoned aiodoned 8787 417423 0 0 3 0x14200 syncer update 11545 313842 0 0 3 0x14200 cleaner cleaner 82402 467841 0 0 3 0x14200 reaper reaper 16959 287845 0 0 3 0x14200 pgdaemon pagedaemon 12947 424326 0 0 3 0x14200 bored crynlk 4646 283786 0 0 3 0x14200 bored crypto 94891 187404 0 0 3 0x40014200 acpi0 acpi0 94372 261364 0 0 3 0x40014200 idle1 26251 317766 0 0 3 0x14200 bored softnet 61945 249985 0 0 3 0x14200 bored systqmp 79154 311338 0 0 3 0x14200 bored systq 52422 249327 0 0 3 0x40014200 bored softclock 47332 425059 0 0 3 0x40014200 idle0 1 492388 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 80135 (syz-executor.1) thread 0xffff800020b42bd0 (116364) exclusive rwlock wsmuxlk r = 0 (0xffff8000019a96d0) locked @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:626 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 wsmux_attach_sc+0x48 sys/dev/wscons/wsmux.c:632 #2 VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 #3 vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 #4 sys_ioctl+0x646 #5 syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] #5 syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 #6 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8235c720) locked @ /syzkaller/managers/multicore/kernel/sys/sys/syscall_mi.h:90 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 syscall+0x47f mi_syscall sys/sys/syscall_mi.h:91 [inline] #1 syscall+0x47f sys/arch/amd64/amd64/trap.c:574 #2 Xsyscall+0x128 Process 36406 (syz-executor.0) thread 0xffff800020b24710 (61729) exclusive rrwlock inode r = 0 (0xfffffd806e5591b8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_ihash.c:140 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 _rw_enter+0x44d sys/kern/kern_rwlock.c:280 #2 _rrw_enter+0x60 sys/kern/kern_rwlock.c:410 #3 ufs_ihashins+0x67 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x13d sys/ufs/ffs/ffs_vfsops.c:1352 #5 ffs_inode_alloc+0x1c3 sys/ufs/ffs/ffs_alloc.c:392 #6 ufs_mkdir+0x10f sys/ufs/ufs/ufs_vnops.c:1164 #7 VOP_MKDIR+0x76 sys/kern/vfs_vops.c:449 #8 domkdirat+0x12d sys/kern/vfs_syscalls.c:2881 #9 syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] #9 syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 #10 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806a1d42b8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 _rw_enter+0x44d sys/kern/kern_rwlock.c:280 #2 _rrw_enter+0x60 sys/kern/kern_rwlock.c:410 #3 VOP_LOCK+0x57 sys/kern/vfs_vops.c:602 #4 vn_lock+0x6e sys/kern/vfs_vnops.c:549 #5 vfs_lookup+0xf5 sys/kern/vfs_lookup.c:387 #6 namei+0x4b2 sys/kern/vfs_lookup.c:224 #7 domkdirat+0x81 sys/kern/vfs_syscalls.c:2866 #8 syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] #8 syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9521 6360K 6368K 78643K 10991 0 0 pcb 23 9K 10K 78643K 571 0 0 rtable 100 3K 4K 78643K 350 0 0 ifaddr 56 13K 14K 78643K 158 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 20 0 0 iov 0 0K 16K 78643K 136 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1198 75K 76K 78643K 1821 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 18 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 142 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 21K 78643K 1067 0 0 sigio 0 0K 0K 78643K 16 0 0 proc 42 38K 58K 78643K 400 0 0 subproc 64 65538K 67586K 78643K 70 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 159 0 0 in_multi 33 2K 2K 78643K 71 0 0 ether_multi 1 0K 0K 78643K 6 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 96 424K 424K 78643K 96 0 0 exec 0 0K 1K 78643K 243 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 88 21K 29K 78643K 4203 0 0 UVM aobj 51 2K 2K 78643K 54 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 25 0 0 NDP 11 0K 0K 78643K 42 0 0 temp 162 2363K 2431K 78643K 5685 0 0 kqueue 0 0K 0K 78643K 14 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 4 0 0 1 0 1 1 0 8 0 inpcbpl 280 493 0 486 1 0 1 1 0 8 0 plimitpl 152 26 0 19 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 41 0 1 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 200 0 196 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 19 0 19 7 7 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 185 0 0 12 0 12 12 0 8 0 art_table 32 186 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 2 1 0 1 1 0 8 0 semapl 112 140 0 130 1 0 1 1 0 8 0 shmpl 112 52 0 3 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3478 0 2066 46 0 46 46 0 8 0 ffsino 272 3478 0 2066 95 0 95 95 0 8 0 nchpl 144 5181 0 3560 61 0 61 61 0 8 0 uvmvnodes 72 3619 0 0 66 0 66 66 0 8 0 vnodes 200 3619 0 0 191 0 191 191 0 8 0 namei 1024 15294 0 15293 2 1 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 3 0 3 2 2 0 1 0 8 0 scxspl 192 14289 0 14288 12 11 1 6 0 8 0 sigapl 432 1238 0 1225 2 0 2 2 0 8 0 futexpl 56 14549 0 14548 1 0 1 1 0 8 0 knotepl 112 385 0 358 4 3 1 2 0 8 0 kqueuepl 104 348 0 346 1 0 1 1 0 8 0 pipepl 112 766 0 747 3 2 1 2 0 8 0 fdescpl 488 1239 0 1225 3 1 2 3 0 8 0 filepl 152 7439 0 7344 9 4 5 5 0 8 1 lockfpl 104 432 0 432 4 3 1 1 0 8 1 lockfspl 32 511 0 511 4 3 1 1 0 8 1 sessionpl 112 20 0 10 1 0 1 1 0 8 0 pgrppl 48 30 0 20 1 0 1 1 0 8 0 ucredpl 96 1933 0 1926 1 0 1 1 0 8 0 zombiepl 144 1225 0 1225 2 1 1 1 0 8 1 processpl 840 1254 0 1225 4 0 4 4 0 8 0 procpl 600 3570 0 3530 4 0 4 4 0 8 0 sosppl 128 15 0 15 6 6 0 1 0 8 0 sockpl 384 1004 0 987 6 3 3 3 0 8 1 mcl64k 65536 256 0 0 32 19 13 32 0 8 1 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 12 0 0 2 0 2 2 0 8 0 mcl9k 9216 8 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 11 0 0 2 0 2 2 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 113 0 0 13 0 13 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 334 0 0 21 0 21 21 0 8 0 bufpl 256 7371 0 1019 397 0 397 397 0 8 0 anonpl 16 132356 0 124530 70 36 34 52 0 125 0 amapchunkpl 152 7193 0 7100 22 17 5 9 0 158 0 amappl16 192 6033 0 5628 60 39 21 33 0 8 0 amappl15 184 533 0 530 1 0 1 1 0 8 0 amappl14 176 535 0 533 2 1 1 1 0 8 0 amappl13 168 30 0 26 1 0 1 1 0 8 0 amappl12 160 17 0 14 1 0 1 1 0 8 0 amappl11 152 178 0 168 1 0 1 1 0 8 0 amappl10 144 1095 0 1093 2 1 1 1 0 8 0 amappl9 136 344 0 339 1 0 1 1 0 8 0 amappl8 128 148 0 121 1 0 1 1 0 8 0 amappl7 120 37 0 32 1 0 1 1 0 8 0 amappl6 112 586 0 578 1 0 1 1 0 8 0 amappl5 104 153 0 141 1 0 1 1 0 8 0 amappl4 96 284 0 261 2 1 1 2 0 8 0 amappl3 88 178 0 173 1 0 1 1 0 8 0 amappl2 80 10661 0 10609 2 0 2 2 0 8 0 amappl1 72 35506 0 35092 23 13 10 19 0 8 0 amappl 72 3791 0 3756 1 0 1 1 0 75 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 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 53 0 3 1 0 1 1 0 8 0 uaddrrnd 24 1239 0 1225 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1239 0 1225 1 0 1 1 0 8 0 vmmpekpl 168 13559 0 13538 2 0 2 2 0 8 0 vmmpepl 168 137268 0 135908 100 35 65 75 0 357 1 vmsppl 360 1238 0 1225 2 0 2 2 0 8 0 pdppl 4096 2485 0 2450 5 0 5 5 0 8 0 pvpl 32 365703 0 354888 176 81 95 133 0 265 0 pmappl 224 1238 0 1225 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 588 0 22 17 0 17 17 0 8 0