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(ffff8000019a7ad0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019a7ad0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019a7ac0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff8000019a7a00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff8000019a7a00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b424c8) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b424c8) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c59680) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd80736447b8,1,fffffd807f7c7ba0,ffff800020b424c8) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c59870,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b424c8,ffffff9c,20000100,0,0,ffff800020c59ab0) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c59b60) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c59b60) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,52bf51b2010) at Xsyscall+0x128 end of kernel end trace frame: 0x52e8bface80, 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(ffff8000019a7ad0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019a7ad0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019a7ac0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff8000019a7a00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff8000019a7a00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b424c8) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b424c8) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c59680) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd80736447b8,1,fffffd807f7c7ba0,ffff800020b424c8) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c59870,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b424c8,ffffff9c,20000100,0,0,ffff800020c59ab0) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c59b60) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c59b60) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,52bf51b2010) at Xsyscall+0x128 end of kernel end trace frame: 0x52e8bface80, count: -11 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c59420 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b49000 rax 0xffff800001747bc0 r8 0xffffffff8155ffb3 kprintf+0x183 r9 0x1 r10 0x25 r11 0x676e7b7f9ec465df 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 0xffff800020c59410 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=454005 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b42978,0xffffffff8233fe30 process=0xffff800020b45078 user=0xffff800020c54000, vmspace=0xfffffd807efffca8 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 35724 280990 23968 0 7 0 syz-executor.1 *35724 454005 23968 0 7 0x4000000 syz-executor.1 26733 501646 44160 0 2 0 syz-executor.0 26733 458433 44160 0 3 0x4000080 fsleep syz-executor.0 74692 245694 1 0 3 0x100083 ttyin getty 6588 364819 0 0 3 0x14200 bored sosplice 23968 241887 433 0 3 0x82 nanosleep syz-executor.1 44160 383603 433 0 3 0x82 nanosleep syz-executor.0 433 318030 69857 0 3 0x82 thrsleep syz-fuzzer 433 358963 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 233943 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 117093 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 61315 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 477056 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 416955 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 512516 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 510345 69857 0 3 0x4000082 kqread syz-fuzzer 433 509618 69857 0 3 0x4000082 thrsleep syz-fuzzer 433 212797 69857 0 3 0x4000082 thrsleep syz-fuzzer 69857 346308 11452 0 3 0x10008a pause ksh 11452 17459 62703 0 3 0x92 select sshd 62703 95117 1 0 3 0x80 select sshd 7686 178427 64333 73 2 0x100090 syslogd 64333 152480 1 0 3 0x100082 netio syslogd 57386 520142 1 77 3 0x100090 poll dhclient 66779 417619 1 0 3 0x80 poll dhclient 72370 260551 0 0 2 0x14200 zerothread 42474 313363 0 0 3 0x14200 aiodoned aiodoned 77837 175649 0 0 3 0x14200 syncer update 41822 443585 0 0 3 0x14200 cleaner cleaner 10454 39531 0 0 3 0x14200 reaper reaper 2961 261578 0 0 3 0x14200 pgdaemon pagedaemon 90500 262325 0 0 3 0x14200 bored crynlk 83454 95080 0 0 3 0x14200 bored crypto 2902 386001 0 0 3 0x40014200 acpi0 acpi0 1542 351122 0 0 3 0x40014200 idle1 29624 431867 0 0 3 0x14200 bored softnet 83654 48726 0 0 3 0x14200 bored systqmp 60362 203617 0 0 3 0x14200 bored systq 1932 129237 0 0 3 0x40014200 bored softclock 28887 258413 0 0 3 0x40014200 idle0 1 249918 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 35724 (syz-executor.1) thread 0xffff800020b424c8 (454005) 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 9520 14548K 14556K 78643K 11152 0 0 pcb 23 9K 10K 78643K 751 0 0 rtable 100 3K 4K 78643K 452 0 0 ifaddr 57 13K 14K 78643K 214 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 37 0 0 iov 0 0K 16K 78643K 169 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1200 75K 75K 78643K 2115 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 29 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 217 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 6 17K 25K 78643K 1513 0 0 sigio 0 0K 0K 78643K 26 0 0 proc 42 38K 70K 78643K 489 0 0 subproc 64 65538K 67586K 78643K 84 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 168 0 0 in_multi 33 2K 2K 78643K 83 0 0 ether_multi 1 0K 0K 78643K 12 0 0 mrt 0 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 90 397K 397K 78643K 90 0 0 exec 0 0K 1K 78643K 294 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 92 22K 30K 78643K 5780 0 0 UVM aobj 86 3K 3K 78643K 94 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 38 0 0 NDP 11 0K 0K 78643K 58 0 0 temp 163 2367K 2435K 78643K 6910 0 0 kqueue 0 0K 0K 78643K 16 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 280 700 0 693 1 0 1 1 0 8 0 plimitpl 152 29 0 22 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 544 256 0 252 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 28 0 28 8 8 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 20 0 10 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 213 0 203 1 0 1 1 0 8 0 shmpl 112 92 0 8 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4365 0 2942 47 0 47 47 0 8 0 ffsino 272 4365 0 2942 96 0 96 96 0 8 0 nchpl 144 6829 0 5207 61 0 61 61 0 8 0 uvmvnodes 72 4554 0 0 83 0 83 83 0 8 0 vnodes 200 4554 0 0 240 0 240 240 0 8 0 namei 1024 20504 0 20504 2 1 1 1 0 8 1 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 19648 0 19648 9 8 1 6 0 8 1 sigapl 432 1682 0 1668 2 0 2 2 0 8 0 futexpl 56 17411 0 17410 1 0 1 1 0 8 0 knotepl 112 449 0 422 6 4 2 2 0 8 1 kqueuepl 104 506 0 504 1 0 1 1 0 8 0 pipepl 112 1040 0 1021 4 2 2 2 0 8 1 fdescpl 488 1683 0 1668 3 1 2 3 0 8 0 filepl 152 10337 0 10242 6 0 6 6 0 8 2 lockfpl 104 540 0 540 2 1 1 1 0 8 1 lockfspl 32 795 0 795 2 1 1 1 0 8 1 sessionpl 112 18 0 8 1 0 1 1 0 8 0 pgrppl 48 36 0 26 1 0 1 1 0 8 0 ucredpl 96 2979 0 2972 1 0 1 1 0 8 0 zombiepl 144 1668 0 1668 2 1 1 1 0 8 1 processpl 840 1698 0 1668 4 0 4 4 0 8 0 procpl 600 5128 0 5086 5 1 4 5 0 8 0 sosppl 128 16 0 16 5 5 0 1 0 8 0 sockpl 384 1340 0 1323 3 0 3 3 0 8 1 mcl64k 65536 889 0 0 107 10 97 97 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 6 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 9 0 0 2 0 2 2 0 8 0 mcl2k2 2112 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 107 0 0 13 1 12 13 0 8 0 mtagpl 80 2 0 0 1 0 1 1 0 8 0 mbufpl 256 952 0 0 52 0 52 52 0 8 0 bufpl 256 8033 0 1061 436 0 436 436 0 8 0 anonpl 16 185932 0 175880 103 55 48 49 0 125 7 amapchunkpl 152 10136 0 9918 32 23 9 9 0 158 0 amappl16 192 9529 0 9104 100 71 29 34 0 8 7 amappl15 184 5 0 3 1 0 1 1 0 8 0 amappl14 176 1505 0 1499 2 1 1 1 0 8 0 amappl13 168 26 0 23 1 0 1 1 0 8 0 amappl12 160 11 0 9 2 1 1 1 0 8 0 amappl11 152 176 0 167 1 0 1 1 0 8 0 amappl10 144 54 0 53 2 1 1 1 0 8 0 amappl9 136 364 0 359 1 0 1 1 0 8 0 amappl8 128 144 0 124 1 0 1 1 0 8 0 amappl7 120 37 0 31 1 0 1 1 0 8 0 amappl6 112 1542 0 1535 1 0 1 1 0 8 0 amappl5 104 120 0 109 1 0 1 1 0 8 0 amappl4 96 282 0 259 1 0 1 1 0 8 0 amappl3 88 192 0 187 1 0 1 1 0 8 0 amappl2 80 15510 0 15445 2 0 2 2 0 8 0 amappl1 72 44818 0 44392 24 14 10 19 0 8 0 amappl 72 5347 0 5310 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 93 0 8 2 0 2 2 0 8 0 uaddrrnd 24 1683 0 1668 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1683 0 1668 1 0 1 1 0 8 0 vmmpekpl 168 17624 0 17603 2 0 2 2 0 8 0 vmmpepl 168 186262 0 184805 120 46 74 75 0 357 9 vmsppl 360 1682 0 1668 2 0 2 2 0 8 0 pdppl 4096 3374 0 3336 6 1 5 6 0 8 0 pvpl 32 518991 0 505847 205 79 126 132 0 265 20 pmappl 224 1682 0 1668 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 735 0 15 21 0 21 21 0 8 0