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(ffff80000197c0d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000197c0d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000197c0c0,ffffffff81f354ca,f2) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000197c000,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:243 [inline] wsmux_mux_open(ffff80000197c000,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:225 wsmux_attach_sc(ffff800000026d00,ffff80000197c000) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:667 VOP_IOCTL(fffffd807a7ebde8,80085761,ffff800020bffc80,3,fffffd807f7c79c0,ffff800020b952d0) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd80691c56a8,80085761,ffff800020bffc80,ffff800020b952d0) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b952d0,ffff800020bffdc8,ffff800020bffdb0) at sys_ioctl+0x646 syscall(ffff800020bffe60) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020bffe60) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,876a44ae010) at Xsyscall+0x128 end of kernel end trace frame: 0x8795c627680, 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(ffff80000197c0d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000197c0d0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000197c0c0,ffffffff81f354ca,f2) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000197c000,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:243 [inline] wsmux_mux_open(ffff80000197c000,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:225 wsmux_attach_sc(ffff800000026d00,ffff80000197c000) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:667 VOP_IOCTL(fffffd807a7ebde8,80085761,ffff800020bffc80,3,fffffd807f7c79c0,ffff800020b952d0) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd80691c56a8,80085761,ffff800020bffc80,ffff800020b952d0) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b952d0,ffff800020bffdc8,ffff800020bffdb0) at sys_ioctl+0x646 syscall(ffff800020bffe60) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020bffe60) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,876a44ae010) at Xsyscall+0x128 end of kernel end trace frame: 0x8795c627680, count: -10 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020bff8b0 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800000947000 rax 0xffff80000092f980 r8 0xffffffff81316553 kprintf+0x183 r9 0x1 r10 0x25 r11 0xafaee006d7006fed 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 0xffff800020bff8a0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=207278 stat=onproc flags process=0 proc=4000000 pri=74, usrpri=74, nice=20 forw=0xffffffffffffffff, list=0xffff800020b94bc8,0xffffffff82334d38 process=0xffff800020b44d30 user=0xffff800020bfa000, vmspace=0xfffffd807f00d870 estcpu=24, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66651 213387 80625 0 2 0 syz-executor.0 *66651 207278 80625 0 7 0x4000000 syz-executor.0 37720 96042 76351 0 3 0x2 biowait syz-executor.1 80625 519374 76351 0 3 0x82 nanosleep syz-executor.0 76351 323150 28310 0 3 0x82 thrsleep syz-fuzzer 76351 175462 28310 0 3 0x4000082 nanosleep syz-fuzzer 76351 224599 28310 0 3 0x4000082 thrsleep syz-fuzzer 76351 38822 28310 0 3 0x4000082 thrsleep syz-fuzzer 76351 143349 28310 0 3 0x4000082 thrsleep syz-fuzzer 76351 245300 28310 0 3 0x4000082 thrsleep syz-fuzzer 76351 504380 28310 0 3 0x4000082 thrsleep syz-fuzzer 76351 112385 28310 0 3 0x4000082 kqread syz-fuzzer 76351 28917 28310 0 3 0x4000082 nanosleep syz-fuzzer 76351 440115 28310 0 3 0x4000082 thrsleep syz-fuzzer 28310 460466 66222 0 3 0x10008a pause ksh 66222 4976 42335 0 3 0x92 select sshd 14075 199415 1 0 3 0x100083 ttyin getty 42335 290081 1 0 3 0x80 select sshd 3345 355268 13595 73 7 0x100090 syslogd 13595 509303 1 0 3 0x100082 netio syslogd 28264 457005 1 77 3 0x100090 poll dhclient 6248 321601 1 0 3 0x80 poll dhclient 28354 351823 0 0 3 0x14200 pgzero zerothread 97737 66419 0 0 3 0x14200 aiodoned aiodoned 92069 290569 0 0 3 0x14200 syncer update 13939 394141 0 0 3 0x14200 cleaner cleaner 33065 345762 0 0 3 0x14200 reaper reaper 70907 398534 0 0 3 0x14200 pgdaemon pagedaemon 21986 371869 0 0 3 0x14200 bored crynlk 26766 213097 0 0 3 0x14200 bored crypto 18066 56275 0 0 3 0x40014200 acpi0 acpi0 41797 253933 0 0 3 0x40014200 idle1 38448 456889 0 0 3 0x14200 bored softnet 96931 223471 0 0 3 0x14200 bored systqmp 61095 381363 0 0 3 0x14200 bored systq 54095 75332 0 0 3 0x40014200 bored softclock 2610 120259 0 0 3 0x40014200 idle0 1 134457 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 66651 (syz-executor.0) thread 0xffff800020b952d0 (207278) exclusive rwlock wsmuxlk r = 0 (0xffff800000026dd0) 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 37720 (syz-executor.1) thread 0xffff800020b244b8 (96042) exclusive rrwlock inode r = 0 (0xfffffd807a9adf80) 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 (0xfffffd806a206918) 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 9475 6343K 6347K 78643K 10610 0 0 pcb 23 9K 10K 78643K 153 0 0 rtable 100 3K 4K 78643K 187 0 0 ifaddr 42 11K 11K 78643K 50 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 19 0 0 iov 0 0K 16K 78643K 14 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1199 75K 75K 78643K 1289 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 1K 1K 78643K 22 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 21K 78643K 169 0 0 sigio 0 0K 0K 78643K 6 0 0 proc 41 38K 58K 78643K 266 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 20 0 0 in_multi 33 2K 2K 78643K 43 0 0 ether_multi 1 0K 0K 78643K 4 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 48 212K 212K 78643K 48 0 0 exec 0 0K 1K 78643K 172 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 20K 78643K 1302 0 0 UVM aobj 13 2K 2K 78643K 13 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 5 0 0 NDP 7 0K 0K 78643K 13 0 0 temp 105 2355K 2419K 78643K 3206 0 0 kqueue 0 0K 0K 78643K 2 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 280 109 0 101 1 0 1 1 0 8 0 plimitpl 152 15 0 8 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 1 0 1 1 1 0 1 0 8 0 tcpcb 544 31 0 26 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 1 0 1 1 1 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 2 0 2 1 1 0 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 17 0 7 1 0 1 1 0 8 0 shmpl 112 11 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1708 0 301 46 0 46 46 0 8 0 ffsino 272 1708 0 301 95 0 95 95 0 8 0 nchpl 144 2156 0 533 61 0 61 61 0 8 0 uvmvnodes 72 1766 0 0 33 0 33 33 0 8 0 vnodes 200 1766 0 0 93 0 93 93 0 8 0 namei 1024 5550 0 5549 2 1 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 5064 0 5063 7 6 1 5 0 8 0 sigapl 432 337 0 324 2 0 2 2 0 8 0 futexpl 56 1726 0 1726 1 0 1 1 0 8 1 knotepl 112 104 0 77 2 1 1 2 0 8 0 kqueuepl 104 48 0 44 1 0 1 1 0 8 0 pipepl 112 240 0 221 3 2 1 2 0 8 0 fdescpl 488 338 0 324 3 1 2 3 0 8 0 filepl 152 1944 0 1847 7 2 5 6 0 8 1 lockfpl 104 76 0 76 2 1 1 1 0 8 1 lockfspl 32 172 0 172 2 1 1 1 0 8 1 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 18 0 8 1 0 1 1 0 8 0 ucredpl 96 353 0 346 1 0 1 1 0 8 0 zombiepl 144 324 0 324 2 1 1 1 0 8 1 processpl 840 352 0 324 4 0 4 4 0 8 0 procpl 600 739 0 701 4 0 4 4 0 8 1 sockpl 384 229 0 211 3 0 3 3 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 108 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 5375 0 1015 273 0 273 273 0 8 0 anonpl 16 36223 0 28503 33 1 32 32 0 125 0 amapchunkpl 152 1635 0 1549 5 0 5 5 0 158 0 amappl16 192 1052 0 651 21 0 21 21 0 8 0 amappl15 184 71 0 69 1 0 1 1 0 8 0 amappl14 176 82 0 77 2 1 1 1 0 8 0 amappl13 168 25 0 22 1 0 1 1 0 8 0 amappl12 160 10 0 9 2 1 1 1 0 8 0 amappl11 152 261 0 250 1 0 1 1 0 8 0 amappl10 144 58 0 55 2 1 1 1 0 8 0 amappl9 136 329 0 325 1 0 1 1 0 8 0 amappl8 128 137 0 118 1 0 1 1 0 8 0 amappl7 120 38 0 33 1 0 1 1 0 8 0 amappl6 112 52 0 45 1 0 1 1 0 8 0 amappl5 104 243 0 230 1 0 1 1 0 8 0 amappl4 96 263 0 243 1 0 1 1 0 8 0 amappl3 88 128 0 123 1 0 1 1 0 8 0 amappl2 80 2229 0 2174 2 0 2 2 0 8 0 amappl1 72 15728 0 15318 24 14 10 19 0 8 0 amappl 72 943 0 910 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 12 0 0 1 0 1 1 0 8 0 uaddrrnd 24 338 0 324 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 338 0 324 1 0 1 1 0 8 0 vmmpekpl 168 6706 0 6685 2 0 2 2 0 8 0 vmmpepl 168 42297 0 40974 87 24 63 71 0 357 1 vmsppl 360 337 0 324 2 0 2 2 0 8 0 pdppl 4096 683 0 648 5 0 5 5 0 8 0 pvpl 32 136107 0 125432 104 13 91 96 0 265 1 pmappl 224 337 0 324 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 418 0 3 12 0 12 12 0 8 0