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(ffff80000198a5d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000198a5d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000198a5c0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000198a500,ffff80000198a450) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff80000198a500,ffff80000198a450) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmux_attach_sc(ffff80000198a400,ffff80000198a500) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:670 VOP_IOCTL(fffffd807a3d6e28,80085761,ffff800020c59760,f,fffffd807f7c77e0,ffff800020b42e28) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8066fd1e60,80085761,ffff800020c59760,ffff800020b42e28) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42e28,ffff800020c598a8,ffff800020c59890) at sys_ioctl+0x646 syscall(ffff800020c59940) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c59940) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,8e97423d010) at Xsyscall+0x128 end of kernel end trace frame: 0x8ec3336cf60, 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(ffff80000198a5d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000198a5d0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000198a5c0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000198a500,ffff80000198a450) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff80000198a500,ffff80000198a450) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmux_attach_sc(ffff80000198a400,ffff80000198a500) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:670 VOP_IOCTL(fffffd807a3d6e28,80085761,ffff800020c59760,f,fffffd807f7c77e0,ffff800020b42e28) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8066fd1e60,80085761,ffff800020c59760,ffff800020b42e28) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42e28,ffff800020c598a8,ffff800020c59890) at sys_ioctl+0x646 syscall(ffff800020c59940) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c59940) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,8e97423d010) at Xsyscall+0x128 end of kernel end trace frame: 0x8ec3336cf60, count: -10 ddb{1}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c59390 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b49000 rax 0xffff800001b47b00 r8 0xffffffff8155ffb3 kprintf+0x183 r9 0x1 r10 0x25 r11 0xb4141ceaf856c772 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 0xffff800020c59380 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=260223 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b42978,0xffffffff8233fe30 process=0xffff800020b45078 user=0xffff800020c54000, vmspace=0xfffffd807efff9d8 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66257 38467 92164 0 7 0 syz-executor.1 *66257 260223 92164 0 7 0x4000000 syz-executor.1 70175 267655 0 0 3 0x14200 bored sosplice 92164 459021 70494 0 3 0x82 nanosleep syz-executor.1 27576 129045 70494 0 3 0x82 nanosleep syz-executor.0 70494 208840 72589 0 3 0x82 thrsleep syz-fuzzer 70494 330035 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 518969 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 477108 72589 0 3 0x4000082 kqread syz-fuzzer 70494 179805 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 76285 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 422761 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 224072 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 399656 72589 0 3 0x4000082 thrsleep syz-fuzzer 70494 2842 72589 0 3 0x4000082 thrsleep syz-fuzzer 72589 251236 42280 0 3 0x10008a pause ksh 42280 116082 69760 0 3 0x92 select sshd 42913 509962 1 0 3 0x100083 ttyin getty 69760 183917 1 0 3 0x80 select sshd 36569 137959 92422 73 2 0x100090 syslogd 92422 197371 1 0 3 0x100082 netio syslogd 83648 288056 1 77 3 0x100090 poll dhclient 85721 384835 1 0 3 0x80 poll dhclient 49276 110464 0 0 3 0x14200 pgzero zerothread 17260 412766 0 0 3 0x14200 aiodoned aiodoned 52391 312020 0 0 3 0x14200 syncer update 39717 33963 0 0 3 0x14200 cleaner cleaner 21644 159787 0 0 3 0x14200 reaper reaper 37245 80127 0 0 3 0x14200 pgdaemon pagedaemon 12390 415316 0 0 3 0x14200 bored crynlk 6939 161627 0 0 3 0x14200 bored crypto 46552 102300 0 0 3 0x40014200 acpi0 acpi0 91003 515618 0 0 3 0x40014200 idle1 93071 383538 0 0 3 0x14200 bored softnet 76576 124185 0 0 3 0x14200 bored systqmp 3860 40826 0 0 3 0x14200 bored systq 47409 184956 0 0 3 0x40014200 bored softclock 50736 123214 0 0 3 0x40014200 idle0 1 406311 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 66257 (syz-executor.1) thread 0xffff800020b42e28 (260223) exclusive rwlock wsmuxlk r = 0 (0xffff80000198a4d0) 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 (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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9498 6349K 6349K 78643K 10672 0 0 pcb 23 9K 10K 78643K 205 0 0 rtable 100 3K 4K 78643K 202 0 0 ifaddr 48 11K 11K 78643K 65 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 15 0 0 iov 0 0K 24K 78643K 29 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1203 75K 75K 78643K 1321 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 7 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 24 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 21K 78643K 213 0 0 proc 41 38K 70K 78643K 287 0 0 subproc 64 65538K 67586K 78643K 68 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 42 0 0 in_multi 33 2K 2K 78643K 38 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 66 291K 291K 78643K 66 0 0 exec 0 0K 1K 78643K 176 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 73 20K 29K 78643K 1405 0 0 UVM aobj 11 2K 2K 78643K 11 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 13 0 0 NDP 9 0K 0K 78643K 17 0 0 temp 118 2355K 2421K 78643K 3353 0 0 kqueue 0 0K 0K 78643K 2 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 4 0 0 1 0 1 1 0 8 0 inpcbpl 280 128 0 121 1 0 1 1 0 8 0 plimitpl 152 17 0 10 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 tcpqe 32 7 0 7 1 1 0 1 0 8 0 tcpcb 544 48 0 44 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 4 0 4 1 0 1 1 0 8 1 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 8 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 18 0 8 1 0 1 1 0 8 0 shmpl 112 9 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1816 0 407 46 0 46 46 0 8 0 ffsino 272 1816 0 407 96 1 95 95 0 8 0 nchpl 144 2315 0 689 61 0 61 61 0 8 0 uvmvnodes 72 1882 0 0 35 0 35 35 0 8 0 vnodes 200 1882 0 0 100 0 100 100 0 8 0 namei 1024 6012 0 6012 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 6096 0 6096 9 7 2 6 0 8 2 sigapl 432 381 0 368 2 0 2 2 0 8 0 futexpl 56 2282 0 2282 1 0 1 1 0 8 1 knotepl 112 108 0 81 2 1 1 2 0 8 0 kqueuepl 104 66 0 64 1 0 1 1 0 8 0 pipepl 112 272 0 251 3 1 2 2 0 8 1 fdescpl 488 382 0 368 3 1 2 3 0 8 0 filepl 152 2146 0 2048 6 1 5 5 0 8 1 lockfpl 104 106 0 106 2 1 1 1 0 8 1 lockfspl 32 164 0 164 2 1 1 1 0 8 1 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 17 0 7 1 0 1 1 0 8 0 ucredpl 96 353 0 346 1 0 1 1 0 8 0 zombiepl 144 368 0 367 2 1 1 1 0 8 0 processpl 840 397 0 367 4 0 4 4 0 8 0 procpl 600 835 0 795 4 0 4 4 0 8 0 sosppl 128 1 0 1 1 1 0 1 0 8 0 sockpl 384 302 0 285 3 0 3 3 0 8 1 mcl64k 65536 5 0 0 1 0 1 1 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 8 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 109 0 0 13 0 13 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 127 0 0 8 0 8 8 0 8 0 bufpl 256 5747 0 1013 296 0 296 296 0 8 0 anonpl 16 43486 0 35841 40 7 33 38 0 125 1 amapchunkpl 152 1922 0 1838 9 5 4 9 0 158 0 amappl16 192 1441 0 1040 23 1 22 22 0 8 1 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 5 0 4 2 1 1 1 0 8 0 amappl13 168 29 0 25 1 0 1 1 0 8 0 amappl12 160 103 0 101 2 1 1 1 0 8 0 amappl11 152 179 0 170 1 0 1 1 0 8 0 amappl10 144 251 0 247 2 1 1 1 0 8 0 amappl9 136 352 0 349 1 0 1 1 0 8 0 amappl8 128 132 0 116 1 0 1 1 0 8 0 amappl7 120 39 0 33 1 0 1 1 0 8 0 amappl6 112 56 0 49 1 0 1 1 0 8 0 amappl5 104 119 0 108 1 0 1 1 0 8 0 amappl4 96 266 0 243 2 1 1 2 0 8 0 amappl3 88 237 0 227 1 0 1 1 0 8 0 amappl2 80 2572 0 2522 2 0 2 2 0 8 0 amappl1 72 16728 0 16313 24 14 10 19 0 8 0 amappl 72 1040 0 1008 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 10 0 0 1 0 1 1 0 8 0 uaddrrnd 24 382 0 368 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 382 0 368 1 0 1 1 0 8 0 vmmpekpl 168 6867 0 6844 2 0 2 2 0 8 0 vmmpepl 168 47068 0 45738 81 17 64 70 0 357 1 vmsppl 360 381 0 368 2 0 2 2 0 8 0 pdppl 4096 772 0 736 6 1 5 6 0 8 0 pvpl 32 151123 0 140528 113 17 96 103 0 265 9 pmappl 224 381 0 368 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 441 0 4 13 0 13 13 0 8 0