witness: acquiring duplicate lock of same type: "&sc->sc_lock" 1st wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:245 2nd wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:245 Starting stack trace... witness_checkorder(ffff8000019950d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019950d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019950c0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff800001995000,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff800001995000,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b43080) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b43080) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c5d1b0) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd80646a9eb0,1,fffffd807f7c78a0,ffff800020b43080) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c5d3a0,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b43080,ffffff9c,20000100,0,0,ffff800020c5d5e0) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c5d690) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c5d690) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,1bbc2317010) at Xsyscall+0x128 end of kernel end trace frame: 0x1be8e21cd80, count: 247 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(ffff8000019950d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019950d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019950c0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff800001995000,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff800001995000,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b43080) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b43080) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c5d1b0) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd80646a9eb0,1,fffffd807f7c78a0,ffff800020b43080) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c5d3a0,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b43080,ffffff9c,20000100,0,0,ffff800020c5d5e0) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c5d690) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c5d690) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,1bbc2317010) at Xsyscall+0x128 end of kernel end trace frame: 0x1be8e21cd80, count: -11 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c5cf50 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800001748000 rax 0xffff800001948700 r8 0xffffffff8155ffb3 kprintf+0x183 r9 0x1 r10 0x25 r11 0x1feb2592afa1d57a r12 0xffffffff81f36129 substchar+0xb4b1 r13 0xf5 r14 0xffffffff81f25d3f apollo_udma33_tim+0x233d r15 0xffffffff81f36129 substchar+0xb4b1 rip 0xffffffff812c7448 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c5cf40 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=360259 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b42270,0xffffffff8233fe30 process=0xffff800020b45708 user=0xffff800020c58000, vmspace=0xfffffd807efff000 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 74540 75751 78427 0 7 0 syz-executor.0 *74540 360259 78427 0 7 0x4000000 syz-executor.0 78427 143218 76199 0 3 0x82 nanosleep syz-executor.0 19937 372855 1 0 3 0x100083 ttyin getty 82084 449207 0 0 3 0x14200 bored sosplice 75097 139513 76199 0 3 0x82 nanosleep syz-executor.1 76199 509655 68224 0 3 0x82 thrsleep syz-fuzzer 76199 466567 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 120857 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 316604 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 509316 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 177205 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 116506 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 510007 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 415693 68224 0 3 0x4000082 thrsleep syz-fuzzer 76199 56053 68224 0 3 0x4000082 kqread syz-fuzzer 68224 410873 25091 0 3 0x10008a pause ksh 25091 197573 42657 0 3 0x92 select sshd 42657 8786 1 0 3 0x80 select sshd 27206 399749 85210 73 2 0x100090 syslogd 85210 143519 1 0 3 0x100082 netio syslogd 9921 73964 1 77 3 0x100090 poll dhclient 61581 46595 1 0 3 0x80 poll dhclient 23469 510735 0 0 2 0x14200 zerothread 64323 381971 0 0 3 0x14200 aiodoned aiodoned 54863 138747 0 0 3 0x14200 syncer update 40329 307347 0 0 3 0x14200 cleaner cleaner 51385 191047 0 0 3 0x14200 reaper reaper 6271 221554 0 0 3 0x14200 pgdaemon pagedaemon 91776 326527 0 0 3 0x14200 bored crynlk 46707 222925 0 0 3 0x14200 bored crypto 43588 421043 0 0 3 0x40014200 acpi0 acpi0 4299 261475 0 0 3 0x40014200 idle1 26873 89498 0 0 3 0x14200 bored softnet 29814 518030 0 0 3 0x14200 bored systqmp 89941 354004 0 0 3 0x14200 bored systq 10822 454871 0 0 3 0x40014200 bored softclock 88469 399617 0 0 3 0x40014200 idle0 1 498499 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 74540 (syz-executor.0) thread 0xffff800020b43080 (360259) shared rwlock wsmuxlk r = 0 (0xffff800000026dd0) locked @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:245 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 wsmuxopen+0xf3 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] #1 wsmuxopen+0xf3 sys/dev/wscons/wsmux.c:204 #2 spec_open+0x217 sys/kern/spec_vnops.c:158 #3 VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 #4 vn_open+0x4c6 sys/kern/vfs_vnops.c:174 #5 doopenat+0x2be sys/kern/vfs_syscalls.c:1045 #6 syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] #6 syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 #7 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8230eba0) 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{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9509 6361K 6365K 78643K 10887 0 0 pcb 23 9K 10K 78643K 441 0 0 rtable 100 3K 4K 78643K 378 0 0 ifaddr 52 12K 13K 78643K 146 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 27 0 0 iov 0 0K 16K 78643K 116 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1198 75K 76K 78643K 1853 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 1070 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 153 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 25K 78643K 1981 0 0 sigio 0 0K 0K 78643K 16 0 0 proc 42 38K 58K 78643K 425 0 0 subproc 64 65538K 67586K 78643K 138 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 118 0 0 in_multi 33 2K 2K 78643K 93 0 0 ether_multi 1 0K 0K 78643K 7 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 238 0 0 pfkey data 0 0K 0K 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 92 21K 30K 78643K 7369 0 0 UVM aobj 130 4K 4K 78643K 131 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 22 0 0 NDP 10 0K 0K 78643K 42 0 0 temp 156 2367K 2439K 78643K 7592 0 0 kqueue 0 0K 0K 78643K 19 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 6 0 2 1 0 1 1 0 8 0 inpcbpl 280 475 0 468 1 0 1 1 0 8 0 plimitpl 152 25 0 18 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 59 0 19 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 175 0 171 1 0 1 1 0 8 0 nd6 48 8 0 4 1 0 1 1 0 8 0 ppxss 1128 15 0 15 8 7 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 272 0 85 12 0 12 12 0 8 0 art_table 32 273 0 85 2 0 2 2 0 8 0 art_node 16 58 0 24 1 0 1 1 0 8 0 sysvmsgpl 40 19 0 11 1 0 1 1 0 8 0 semapl 112 151 0 141 1 0 1 1 0 8 0 shmpl 112 129 0 1 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4337 0 2930 46 0 46 46 0 8 0 ffsino 272 4337 0 2930 95 0 95 95 0 8 0 nchpl 144 6980 0 5371 61 0 61 61 0 8 0 uvmvnodes 72 4503 0 0 82 0 82 82 0 8 0 vnodes 200 4503 0 0 237 0 237 237 0 8 0 namei 1024 18800 0 18800 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 2 0 2 1 1 0 1 0 8 0 scxspl 192 18491 0 18491 14 13 1 6 0 8 1 sigapl 432 2144 0 2131 2 0 2 2 0 8 0 futexpl 56 24649 0 24649 1 0 1 1 0 8 1 knotepl 112 368 0 341 4 3 1 2 0 8 0 kqueuepl 104 313 0 311 1 0 1 1 0 8 0 pipepl 112 702 0 683 3 2 1 2 0 8 0 fdescpl 488 2145 0 2131 3 1 2 3 0 8 0 filepl 152 8130 0 8035 9 4 5 5 0 8 1 lockfpl 104 292 0 292 4 3 1 1 0 8 1 lockfspl 32 439 0 439 4 3 1 1 0 8 1 sessionpl 112 20 0 10 1 0 1 1 0 8 0 pgrppl 48 22 0 12 1 0 1 1 0 8 0 ucredpl 96 6227 0 6219 1 0 1 1 0 8 0 zombiepl 144 2131 0 2130 2 1 1 1 0 8 0 processpl 840 2160 0 2130 4 0 4 4 0 8 0 procpl 600 6702 0 6662 4 0 4 4 0 8 0 srpgc 64 12 0 12 1 1 0 1 0 8 0 sosppl 128 13 0 13 3 3 0 1 0 8 0 sockpl 384 849 0 832 5 2 3 3 0 8 1 mcl64k 65536 232 0 0 29 0 29 29 0 8 1 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 7 0 0 1 0 1 1 0 8 0 mcl9k 9216 6 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 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 118 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 376 0 0 20 0 20 20 0 8 0 bufpl 256 7806 0 1020 425 0 425 425 0 8 0 anonpl 16 187636 0 179797 74 25 49 49 0 125 14 amapchunkpl 152 12359 0 12272 16 11 5 9 0 158 0 amappl16 192 10093 0 9679 58 29 29 33 0 8 8 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 13 0 11 2 1 1 1 0 8 0 amappl13 168 1189 0 1185 1 0 1 1 0 8 0 amappl12 160 9 0 9 1 1 0 1 0 8 0 amappl11 152 431 0 420 1 0 1 1 0 8 0 amappl10 144 1138 0 1135 1 0 1 1 0 8 0 amappl9 136 601 0 594 1 0 1 1 0 8 0 amappl8 128 162 0 136 1 0 1 1 0 8 0 amappl7 120 43 0 36 1 0 1 1 0 8 0 amappl6 112 56 0 49 1 0 1 1 0 8 0 amappl5 104 132 0 121 1 0 1 1 0 8 0 amappl4 96 1442 0 1418 1 0 1 1 0 8 0 amappl3 88 170 0 164 1 0 1 1 0 8 0 amappl2 80 19933 0 19882 2 0 2 2 0 8 0 amappl1 72 56436 0 56022 24 14 10 19 0 8 0 amappl 72 6932 0 6899 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 64 130 0 1 3 0 3 3 0 8 0 uaddrrnd 24 2145 0 2131 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2145 0 2131 1 0 1 1 0 8 0 vmmpekpl 168 21332 0 21306 2 0 2 2 0 8 0 vmmpepl 168 232272 0 230916 115 40 75 75 0 357 11 vmsppl 360 2144 0 2131 2 0 2 2 0 8 0 pdppl 4096 4298 0 4262 6 1 5 6 0 8 0 pvpl 32 521122 0 510286 168 42 126 126 0 265 35 pmappl 224 2144 0 2131 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 614 0 4 18 0 18 18 0 8 0