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(ffff800001982ad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff800001982ad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff800001982ac0,ffffffff81f33463,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff800001982a00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff800001982a00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b439e0) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b439e0) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c4b990) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd8064632b48,1,fffffd807f7c7a20,ffff800020b439e0) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c4bb80,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b439e0,ffffff9c,20000100,0,0,ffff800020c4bdc0) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c4be70) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c4be70) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,e9a1bc40010) at Xsyscall+0x128 end of kernel end trace frame: 0xe9c9792b6c0, 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(ffff800001982ad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff800001982ad0,1,ffffffff81f33463,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff800001982ac0,ffffffff81f33463,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff800001982a00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff800001982a00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmuxopen(4500,1,2000,ffff800020b439e0) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:258 [inline] wsmuxopen(4500,1,2000,ffff800020b439e0) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:204 spec_open(ffff800020c4b990) at spec_open+0x217 sys/kern/spec_vnops.c:158 VOP_OPEN(fffffd8064632b48,1,fffffd807f7c7a20,ffff800020b439e0) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153 vn_open(ffff800020c4bb80,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174 doopenat(ffff800020b439e0,ffffff9c,20000100,0,0,ffff800020c4bdc0) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045 syscall(ffff800020c4be70) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c4be70) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffffb1,0,4,e9a1bc40010) at Xsyscall+0x128 end of kernel end trace frame: 0xe9c9792b6c0, count: -11 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c4b730 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b4a000 rax 0xffff800001547b80 r8 0xffffffff818cb2f3 kprintf+0x183 r9 0x1 r10 0x25 r11 0x72596382bc6e7182 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 0xffff800020c4b720 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=449502 stat=onproc flags process=0 proc=4000000 pri=73, usrpri=73, nice=20 forw=0xffffffffffffffff, list=0xffff800020b432d8,0xffffffff8234a810 process=0xffff800020b45708 user=0xffff800020c46000, vmspace=0xfffffd807effe870 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 80157 219683 49387 0 2 0 syz-executor.1 *80157 449502 49387 0 7 0x4000000 syz-executor.1 61579 112507 53996 0 3 0x80 nanosleep syz-executor.0 61579 351576 53996 0 3 0x4000000 physio syz-executor.0 61579 42898 53996 0 3 0x4000080 fsleep syz-executor.0 67460 258949 0 0 3 0x14200 bored sosplice 49387 238845 25862 0 3 0x82 nanosleep syz-executor.1 53996 188970 25862 0 3 0x82 nanosleep syz-executor.0 25862 494034 78423 0 3 0x82 thrsleep syz-fuzzer 25862 424139 78423 0 3 0x4000082 nanosleep syz-fuzzer 25862 122492 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 152850 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 304984 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 395237 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 462875 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 7630 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 513749 78423 0 3 0x4000082 thrsleep syz-fuzzer 25862 126055 78423 0 3 0x4000082 kqread syz-fuzzer 78423 37927 80094 0 3 0x10008a pause ksh 80094 383727 572 0 3 0x92 select sshd 27853 47398 1 0 3 0x100083 ttyin getty 572 29527 1 0 3 0x80 select sshd 99074 162337 35893 73 7 0x100090 syslogd 35893 368602 1 0 3 0x100082 netio syslogd 31205 344109 1 77 3 0x100090 poll dhclient 81446 351346 1 0 3 0x80 poll dhclient 33754 495842 0 0 2 0x14200 zerothread 89741 264189 0 0 3 0x14200 aiodoned aiodoned 56379 123010 0 0 3 0x14200 syncer update 84037 512703 0 0 3 0x14200 cleaner cleaner 49025 440201 0 0 3 0x14200 reaper reaper 43694 446109 0 0 3 0x14200 pgdaemon pagedaemon 2574 199347 0 0 3 0x14200 bored crynlk 25766 335460 0 0 3 0x14200 bored crypto 46494 243288 0 0 3 0x40014200 acpi0 acpi0 54318 321132 0 0 3 0x40014200 idle1 67306 441120 0 0 3 0x14200 bored softnet 34361 498764 0 0 3 0x14200 bored systqmp 62954 388715 0 0 3 0x14200 bored systq 82831 120941 0 0 3 0x40014200 bored softclock 14073 277655 0 0 3 0x40014200 idle0 1 179220 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 80157 (syz-executor.1) thread 0xffff800020b439e0 (449502) 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 61579 (syz-executor.0) thread 0xffff800020b42018 (351576) shared rwlock vmmaplk r = 0 (0xfffffd807effe5b8) locked @ /syzkaller/managers/multicore/kernel/sys/uvm/uvm_glue.c:173 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 uvm_vslock_device+0x11e sys/uvm/uvm_glue.c:174 #2 physio+0x27a sys/kern/kern_physio.c:139 #3 spec_write+0xe3 sys/kern/spec_vnops.c:310 #4 VOP_WRITE+0x76 sys/kern/vfs_vops.c:268 #5 vn_write+0x1fd sys/kern/vfs_vnops.c:397 #6 dofilewritev+0x1b0 sys/kern/sys_generic.c:364 #7 sys_pwritev+0xd9 sys/kern/vfs_syscalls.c:3161 #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 9496 6365K 6381K 78643K 10753 0 0 pcb 26 9K 10K 78643K 322 0 0 rtable 100 3K 4K 78643K 252 0 0 ifaddr 50 12K 12K 78643K 98 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 25 0 0 iov 0 0K 16K 78643K 63 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1198 75K 75K 78643K 1527 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 15 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 80 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 6 17K 25K 78643K 522 0 0 sigio 0 0K 0K 78643K 8 0 0 proc 42 38K 70K 78643K 295 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 58 0 0 in_multi 33 2K 2K 78643K 70 0 0 ether_multi 1 0K 0K 78643K 9 0 0 mrt 0 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 54 238K 238K 78643K 54 0 0 exec 0 0K 1K 78643K 209 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 89 21K 29K 78643K 2413 0 0 UVM aobj 36 2K 2K 78643K 37 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 9 0K 0K 78643K 25 0 0 temp 148 2366K 2431K 78643K 4204 0 0 kqueue 0 0K 0K 78643K 15 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 280 276 0 269 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 544 103 0 99 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 10 0 10 4 3 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 184 0 0 12 0 12 12 0 8 0 art_table 32 185 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 15 0 9 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 76 0 66 1 0 1 1 0 8 0 shmpl 112 35 0 1 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2402 0 1006 46 0 46 46 0 8 0 ffsino 272 2402 0 1006 94 0 94 94 0 8 0 nchpl 144 3352 0 1729 61 0 61 61 0 8 0 uvmvnodes 72 2505 0 0 46 0 46 46 0 8 0 vnodes 200 2505 0 0 132 0 132 132 0 8 0 namei 1024 9169 0 9169 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 8277 0 8276 11 10 1 7 0 8 0 sigapl 432 690 0 676 2 0 2 2 0 8 0 futexpl 56 6134 0 6133 1 0 1 1 0 8 0 knotepl 112 214 0 187 3 1 2 2 0 8 1 kqueuepl 104 210 0 208 1 0 1 1 0 8 0 pipepl 112 424 0 405 3 2 1 2 0 8 0 fdescpl 488 691 0 676 3 1 2 3 0 8 0 filepl 152 4118 0 4019 6 1 5 5 0 8 0 lockfpl 104 182 0 182 2 1 1 1 0 8 1 lockfspl 32 241 0 241 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 1002 0 995 1 0 1 1 0 8 0 zombiepl 144 676 0 676 2 1 1 1 0 8 1 processpl 840 706 0 676 4 0 4 4 0 8 0 procpl 600 1806 0 1764 4 0 4 4 0 8 0 sosppl 128 8 0 8 3 3 0 1 0 8 0 sockpl 384 546 0 526 3 0 3 3 0 8 1 mcl64k 65536 11 0 0 2 0 2 2 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 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 256 134 0 0 8 0 8 8 0 8 0 bufpl 256 6089 0 1021 317 0 317 317 0 8 0 anonpl 16 86177 0 77445 52 11 41 50 0 125 5 amapchunkpl 152 4170 0 4071 9 4 5 9 0 158 0 amappl16 192 3597 0 3132 43 19 24 34 0 8 0 amappl15 184 243 0 240 1 0 1 1 0 8 0 amappl14 176 246 0 243 2 1 1 1 0 8 0 amappl13 168 25 0 22 1 0 1 1 0 8 0 amappl12 160 16 0 13 1 0 1 1 0 8 0 amappl11 152 177 0 168 1 0 1 1 0 8 0 amappl10 144 61 0 56 1 0 1 1 0 8 0 amappl9 136 354 0 351 1 0 1 1 0 8 0 amappl8 128 133 0 116 1 0 1 1 0 8 0 amappl7 120 40 0 33 1 0 1 1 0 8 0 amappl6 112 297 0 289 1 0 1 1 0 8 0 amappl5 104 124 0 113 1 0 1 1 0 8 0 amappl4 96 538 0 513 2 1 1 2 0 8 0 amappl3 88 150 0 145 1 0 1 1 0 8 0 amappl2 80 5446 0 5387 2 0 2 2 0 8 0 amappl1 72 23569 0 23131 23 13 10 19 0 8 0 amappl 72 2019 0 1981 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 36 0 1 1 0 1 1 0 8 0 uaddrrnd 24 691 0 676 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 691 0 676 1 0 1 1 0 8 0 vmmpekpl 168 9282 0 9260 2 0 2 2 0 8 0 vmmpepl 168 78571 0 77078 91 26 65 73 0 357 0 vmsppl 360 690 0 676 2 0 2 2 0 8 0 pdppl 4096 1390 0 1352 6 1 5 6 0 8 0 pvpl 32 237592 0 225808 134 16 118 128 0 265 22 pmappl 224 690 0 676 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 464 0 4 14 0 14 14 0 8 0