login: witness: acquiring duplicate lock of same type: "&sc->sc_lock" 1st wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:629 2nd wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:245 Starting stack trace... witness_checkorder(ffff80000199c1d0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000199c1d0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000199c1c0,ffffffff81f33463,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000199c100,ffff800002b49150) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff80000199c100,ffff800002b49150) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmux_attach_sc(ffff800002b49100,ffff80000199c100) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:670 VOP_IOCTL(fffffd80653ffa70,80085761,ffff800020bfd730,3,fffffd807f7c7c00,ffff800020b42bd0) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8069311998,80085761,ffff800020bfd730,ffff800020b42bd0) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42bd0,ffff800020bfd878,ffff800020bfd860) at sys_ioctl+0x646 syscall(ffff800020bfd910) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020bfd910) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,fde1a0b6010) at Xsyscall+0x128 end of kernel end trace frame: 0xfe0d2c34f60, count: 248 End of stack trace. 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:399 witness_checkorder(ffff80000199c1d0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000199c1d0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000199c1c0,ffffffff81f33463,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000199c100,ffff800002b49150) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff80000199c100,ffff800002b49150) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmux_attach_sc(ffff800002b49100,ffff80000199c100) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:670 VOP_IOCTL(fffffd80653ffa70,80085761,ffff800020bfd730,3,fffffd807f7c7c00,ffff800020b42bd0) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8069311998,80085761,ffff800020bfd730,ffff800020b42bd0) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42bd0,ffff800020bfd878,ffff800020bfd860) at sys_ioctl+0x646 syscall(ffff800020bfd910) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020bfd910) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,fde1a0b6010) at Xsyscall+0x128 end of kernel end trace frame: 0xfe0d2c34f60, count: -10 ddb{1}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020bfd360 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b4a000 rax 0xffff800001947f00 r8 0xffffffff818cb2f3 kprintf+0x183 r9 0x1 r10 0x25 r11 0x7f591edb01eaee7d r12 0xffffffff81f33463 substchar+0x92c4 r13 0xf5 r14 0xffffffff81f22d40 cmd680_setup_channel.udma_tbl+0x3c0b r15 0xffffffff81f33463 substchar+0x92c4 rip 0xffffffff811a46a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020bfd350 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=272679 stat=onproc flags process=0 proc=4000000 pri=77, usrpri=77, nice=20 forw=0xffffffffffffffff, list=0xffff800020b424c8,0xffff800020b42028 process=0xffff800020b0b3b8 user=0xffff800020bf8000, vmspace=0xfffffd807effe870 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 80340 424546 94474 0 2 0 syz-executor.0 15929 405704 53413 0 7 0 syz-executor.1 *15929 272679 53413 0 7 0x4000000 syz-executor.1 66103 473920 1 0 3 0x100083 ttyin getty 94474 207387 52153 0 3 0x82 nanosleep syz-executor.0 53413 111496 52153 0 3 0x82 nanosleep syz-executor.1 71856 330106 0 0 3 0x14200 bored sosplice 52153 175615 43842 0 3 0x82 thrsleep syz-fuzzer 52153 367094 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 153947 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 65502 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 518795 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 290589 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 16450 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 120260 43842 0 3 0x4000082 kqread syz-fuzzer 52153 93902 43842 0 3 0x4000082 thrsleep syz-fuzzer 52153 144920 43842 0 3 0x4000082 thrsleep syz-fuzzer 43842 278779 84148 0 3 0x10008a pause ksh 84148 303513 63945 0 3 0x92 select sshd 63945 458221 1 0 3 0x80 select sshd 34090 457070 96776 73 2 0x100090 syslogd 96776 36563 1 0 3 0x100082 netio syslogd 1016 67207 1 77 3 0x100090 poll dhclient 41315 434639 1 0 3 0x80 poll dhclient 96875 226474 0 0 2 0x14200 zerothread 77493 17633 0 0 3 0x14200 aiodoned aiodoned 81661 167711 0 0 3 0x14200 syncer update 36172 331618 0 0 3 0x14200 cleaner cleaner 20092 187296 0 0 3 0x14200 reaper reaper 60311 12665 0 0 3 0x14200 pgdaemon pagedaemon 86853 491998 0 0 3 0x14200 bored crynlk 32537 36271 0 0 3 0x14200 bored crypto 98647 162870 0 0 3 0x40014200 acpi0 acpi0 77945 350060 0 0 3 0x40014200 idle1 59726 503797 0 0 3 0x14200 bored softnet 10342 180339 0 0 3 0x14200 bored systqmp 28909 10694 0 0 3 0x14200 bored systq 19960 243647 0 0 3 0x40014200 bored softclock 48744 25764 0 0 3 0x40014200 idle0 1 368701 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 15929 (syz-executor.1) thread 0xffff800020b42bd0 (272679) exclusive rwlock wsmuxlk r = 0 (0xffff800002b491d0) locked @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:629 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 wsmux_attach_sc+0x48 sys/dev/wscons/wsmux.c:635 #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 (0xffffffff82360c40) 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 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9514 14557K 14557K 78643K 10896 0 0 pcb 25 9K 10K 78643K 543 0 0 rtable 100 3K 4K 78643K 412 0 0 ifaddr 53 13K 14K 78643K 154 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 21 0 0 iov 0 0K 20K 78643K 111 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1192 75K 75K 78643K 1789 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 15 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 140 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 6 17K 21K 78643K 950 0 0 sigio 0 0K 0K 78643K 21 0 0 proc 42 38K 70K 78643K 463 0 0 subproc 64 65538K 67586K 78643K 170 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 109 0 0 in_multi 33 2K 2K 78643K 117 0 0 ether_multi 1 0K 0K 78643K 10 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 271 0 0 pfkey data 0 0K 4K 78643K 2 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 87 20K 29K 78643K 3872 0 0 UVM aobj 55 3K 3K 78643K 59 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 34 0 0 NDP 10 0K 0K 78643K 45 0 0 temp 156 2367K 2437K 78643K 5508 0 0 kqueue 0 0K 0K 78643K 7 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 7 0 3 1 0 1 1 0 8 0 inpcbpl 280 468 0 460 1 0 1 1 0 8 0 plimitpl 152 37 0 30 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 68 0 28 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 191 0 187 1 0 1 1 0 8 0 nd6 48 10 0 6 1 0 1 1 0 8 0 ppxss 1128 17 0 17 6 6 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 311 0 123 12 0 12 12 0 8 0 art_table 32 312 0 123 2 0 2 2 0 8 0 art_node 16 67 0 33 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 0 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 136 0 126 1 0 1 1 0 8 0 shmpl 112 57 0 4 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3214 0 1803 46 0 46 46 0 8 0 ffsino 272 3214 0 1803 95 0 95 95 0 8 0 nchpl 144 4816 0 3211 61 0 61 61 0 8 0 uvmvnodes 72 3368 0 0 62 0 62 62 0 8 0 vnodes 200 3368 0 0 178 0 178 178 0 8 0 namei 1024 14396 0 14396 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 5 0 5 3 3 0 1 0 8 0 scxspl 192 12607 0 12607 12 11 1 6 0 8 1 sigapl 432 1111 0 1097 2 0 2 2 0 8 0 futexpl 56 10887 0 10887 1 0 1 1 0 8 1 knotepl 112 345 0 318 4 3 1 2 0 8 0 kqueuepl 104 292 0 290 1 0 1 1 0 8 0 pipepl 112 798 0 779 5 4 1 2 0 8 0 fdescpl 488 1112 0 1097 3 1 2 3 0 8 0 filepl 152 6978 0 6880 8 3 5 5 0 8 1 lockfpl 104 336 0 336 2 1 1 1 0 8 1 lockfspl 32 471 0 471 2 1 1 1 0 8 1 sessionpl 112 22 0 12 1 0 1 1 0 8 0 pgrppl 48 36 0 26 1 0 1 1 0 8 0 ucredpl 96 2055 0 2048 1 0 1 1 0 8 0 zombiepl 144 1097 0 1097 2 1 1 1 0 8 1 processpl 840 1127 0 1097 4 0 4 4 0 8 0 procpl 600 3191 0 3151 4 0 4 4 0 8 0 srpgc 64 18 0 18 2 2 0 1 0 8 0 sosppl 128 15 0 15 3 2 1 1 0 8 1 sockpl 384 954 0 934 4 1 3 3 0 8 1 mcl64k 65536 16 0 0 2 0 2 2 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 14 0 0 2 0 2 2 0 8 0 mcl9k 9216 7 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 13 0 0 2 0 2 2 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 114 0 0 13 0 13 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 154 0 0 9 0 9 9 0 8 0 bufpl 256 7141 0 1019 383 0 383 383 0 8 0 anonpl 16 114160 0 106262 77 36 41 48 0 125 8 amapchunkpl 152 6604 0 6505 17 8 9 9 0 158 4 amappl16 192 5219 0 4817 46 24 22 33 0 8 1 amappl15 184 295 0 294 1 0 1 1 0 8 0 amappl14 176 6 0 4 2 1 1 1 0 8 0 amappl13 168 192 0 187 1 0 1 1 0 8 0 amappl12 160 14 0 12 2 1 1 1 0 8 0 amappl11 152 342 0 333 1 0 1 1 0 8 0 amappl10 144 682 0 676 2 1 1 1 0 8 0 amappl9 136 499 0 496 1 0 1 1 0 8 0 amappl8 128 175 0 149 2 1 1 2 0 8 0 amappl7 120 44 0 37 1 0 1 1 0 8 0 amappl6 112 59 0 50 1 0 1 1 0 8 0 amappl5 104 452 0 441 1 0 1 1 0 8 0 amappl4 96 445 0 421 1 0 1 1 0 8 0 amappl3 88 175 0 169 1 0 1 1 0 8 0 amappl2 80 9729 0 9677 2 0 2 2 0 8 0 amappl1 72 32620 0 32214 23 13 10 19 0 8 0 amappl 72 3431 0 3394 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 58 0 4 1 0 1 1 0 8 0 uaddrrnd 24 1112 0 1097 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1112 0 1097 1 0 1 1 0 8 0 vmmpekpl 168 13089 0 13069 2 0 2 2 0 8 0 vmmpepl 168 123064 0 121681 112 48 64 74 0 357 0 vmsppl 360 1111 0 1097 2 0 2 2 0 8 0 pdppl 4096 2232 0 2194 6 1 5 6 0 8 0 pvpl 32 340157 0 329210 173 63 110 123 0 265 19 pmappl 224 1111 0 1097 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 533 0 4 16 0 16 16 0 8 0