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(ffff80000197aad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000197aad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000197aac0,ffffffff81f33463,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000197aa00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff80000197aa00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b43530) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b43530) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c3ec50) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd807c73f440,1,fffffd807f7c7a80,ffff800020b43530) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c3ee40,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b43530,ffffff9c,20000000,0,0,ffff800020c3f080) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c3f130) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c3f130) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,7bb31664010) at Xsyscall+0x128 end of kernel end trace frame: 0x7bd5b7eedd0, 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(ffff80000197aad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff80000197aad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff80000197aac0,ffffffff81f33463,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff80000197aa00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff80000197aa00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b43530) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b43530) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c3ec50) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd807c73f440,1,fffffd807f7c7a80,ffff800020b43530) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c3ee40,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b43530,ffffff9c,20000000,0,0,ffff800020c3f080) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c3f130) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c3f130) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,7bb31664010) at Xsyscall+0x128 end of kernel end trace frame: 0x7bd5b7eedd0, count: -11 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c3e9f0 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800000947000 rax 0xffff800000941a80 r8 0xffffffff818cb2f3 kprintf+0x183 r9 0x1 r10 0x25 r11 0xa67393b0851534ca 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 0xffff800020c3e9e0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=206654 stat=onproc flags process=0 proc=4000000 pri=78, usrpri=78, nice=20 forw=0xffffffffffffffff, list=0xffff800020b43788,0xffffffff8234a810 process=0xffff800020b44010 user=0xffff800020c3a000, vmspace=0xfffffd807effe438 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 65376 140969 28791 0 7 0 syz-executor.0 *65376 206654 28791 0 7 0x4000000 syz-executor.0 95295 210692 0 0 3 0x14200 bored sosplice 11198 90168 84044 0 3 0x82 nanosleep syz-executor.1 28791 176506 84044 0 3 0x82 nanosleep syz-executor.0 84044 420975 18268 0 3 0x82 thrsleep syz-fuzzer 84044 463196 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 37470 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 48549 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 104060 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 61482 18268 0 3 0x4000082 kqread syz-fuzzer 84044 56038 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 447602 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 141252 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 305893 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 14231 18268 0 3 0x4000082 thrsleep syz-fuzzer 84044 348174 18268 0 3 0x4000082 thrsleep syz-fuzzer 18268 509793 7388 0 3 0x10008a pause ksh 7388 89344 72743 0 3 0x92 select sshd 5101 520175 1 0 3 0x100083 ttyin getty 72743 307606 1 0 3 0x80 select sshd 32549 238300 49810 73 3 0x100010 ffs_fsync syslogd 49810 147871 1 0 3 0x100082 netio syslogd 5705 480873 1 77 3 0x100090 poll dhclient 48230 214492 1 0 3 0x80 poll dhclient 41834 230359 0 0 3 0x14200 pgzero zerothread 43038 48694 0 0 3 0x14200 aiodoned aiodoned 62838 421291 0 0 3 0x14200 syncer update 13611 343605 0 0 3 0x14200 cleaner cleaner 79237 62052 0 0 3 0x14200 reaper reaper 46120 239600 0 0 3 0x14200 pgdaemon pagedaemon 75054 234987 0 0 3 0x14200 bored crynlk 5290 522256 0 0 3 0x14200 bored crypto 74345 453928 0 0 3 0x40014200 acpi0 acpi0 33081 49039 0 0 3 0x40014200 idle1 57450 271294 0 0 3 0x14200 bored softnet 67597 122044 0 0 3 0x14200 bored systqmp 79120 85798 0 0 3 0x14200 bored systq 89228 221744 0 0 3 0x40014200 bored softclock 89398 460773 0 0 3 0x40014200 idle0 1 341610 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 65376 (syz-executor.0) thread 0xffff800020b43530 (206654) 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 (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 Process 32549 (syslogd) thread 0xffff800020b95c30 (238300) exclusive rrwlock inode r = 0 (0xfffffd807659e6f8) 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 sys_fsync+0x114 sys/kern/vfs_syscalls.c:2704 #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 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9486 6345K 6345K 78643K 10698 0 0 pcb 23 9K 10K 78643K 234 0 0 rtable 100 3K 4K 78643K 220 0 0 ifaddr 47 11K 12K 78643K 75 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 19 0 0 iov 0 0K 24K 78643K 34 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1195 75K 75K 78643K 1392 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 53 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 25K 78643K 372 0 0 proc 42 38K 58K 78643K 277 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 40 0 0 in_multi 33 2K 2K 78643K 45 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 60 265K 265K 78643K 60 0 0 exec 0 0K 1K 78643K 185 0 0 pfkey data 0 0K 0K 78643K 1 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 82 20K 21K 78643K 1881 0 0 UVM aobj 21 2K 2K 78643K 22 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 8 0K 0K 78643K 19 0 0 temp 115 2356K 2422K 78643K 3743 0 0 kqueue 0 0K 0K 78643K 5 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 280 170 0 163 1 0 1 1 0 8 0 plimitpl 152 16 0 9 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 58 0 54 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 7 0 7 2 1 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 12 0 4 1 0 1 1 0 8 0 semapl 112 51 0 41 1 0 1 1 0 8 0 shmpl 112 20 0 1 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2087 0 688 46 0 46 46 0 8 0 ffsino 272 2087 0 688 95 0 95 95 0 8 0 nchpl 144 2825 0 1180 61 0 61 61 0 8 0 uvmvnodes 72 2157 0 0 40 0 40 40 0 8 0 vnodes 200 2157 0 0 114 0 114 114 0 8 0 namei 1024 7331 0 7331 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 6913 0 6912 7 6 1 6 0 8 0 sigapl 432 540 0 527 2 0 2 2 0 8 0 futexpl 56 3557 0 3557 1 0 1 1 0 8 1 knotepl 112 148 0 121 2 1 1 2 0 8 0 kqueuepl 104 94 0 92 1 0 1 1 0 8 0 pipepl 112 256 0 237 2 1 1 1 0 8 0 fdescpl 488 541 0 527 3 1 2 3 0 8 0 filepl 152 2821 0 2726 7 2 5 5 0 8 1 lockfpl 104 110 0 110 2 1 1 1 0 8 1 lockfspl 32 137 0 137 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 96 545 0 538 1 0 1 1 0 8 0 zombiepl 144 527 0 526 2 1 1 1 0 8 0 processpl 840 556 0 526 4 0 4 4 0 8 0 procpl 600 1299 0 1257 4 0 4 4 0 8 0 sosppl 128 2 0 2 1 1 0 1 0 8 0 sockpl 384 352 0 335 3 0 3 3 0 8 1 mcl64k 65536 512 0 0 64 0 64 64 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 122 0 0 15 0 15 15 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 623 0 0 37 0 37 37 0 8 0 bufpl 256 5736 0 1015 296 0 296 296 0 8 0 anonpl 16 61203 0 53536 53 13 40 48 0 125 8 amapchunkpl 152 2537 0 2450 6 2 4 5 0 158 0 amappl16 192 2671 0 2268 40 18 22 33 0 8 1 amappl15 184 1 0 1 1 1 0 1 0 8 0 amappl14 176 10 0 8 2 1 1 1 0 8 0 amappl13 168 25 0 22 1 0 1 1 0 8 0 amappl12 160 205 0 203 2 1 1 1 0 8 0 amappl11 152 336 0 326 1 0 1 1 0 8 0 amappl10 144 56 0 53 2 1 1 1 0 8 0 amappl9 136 517 0 511 1 0 1 1 0 8 0 amappl8 128 330 0 309 1 0 1 1 0 8 0 amappl7 120 40 0 33 1 0 1 1 0 8 0 amappl6 112 53 0 47 1 0 1 1 0 8 0 amappl5 104 116 0 105 1 0 1 1 0 8 0 amappl4 96 269 0 247 1 0 1 1 0 8 0 amappl3 88 138 0 132 1 0 1 1 0 8 0 amappl2 80 4158 0 4105 2 0 2 2 0 8 0 amappl1 72 19530 0 19124 23 13 10 19 0 8 0 amappl 72 1506 0 1472 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 21 0 1 1 0 1 1 0 8 0 uaddrrnd 24 541 0 527 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 541 0 527 1 0 1 1 0 8 0 vmmpekpl 168 7779 0 7759 2 0 2 2 0 8 0 vmmpepl 168 63107 0 61772 92 26 66 74 0 357 4 vmsppl 360 540 0 527 2 0 2 2 0 8 0 pdppl 4096 1090 0 1054 6 1 5 6 0 8 0 pvpl 32 192188 0 181558 139 22 117 125 0 265 29 pmappl 224 540 0 527 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 537 0 4 16 0 16 16 0 8 0