witness: acquiring duplicate lock of same type: "&sc->sc_lock" 1st wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:519 2nd wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:519 Starting stack trace... witness_checkorder(ffff8000019705d0,1,ffffffff81f354ca,207,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019705d0,1,ffffffff81f354ca,207,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019705c0,ffffffff81f354ca,207) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_do_ioctl(ffff800001970500,80585750,ffff800020c3d830,82,ffff800020b42270) at wsmux_do_ioctl+0x4ef wsmux_do_ioctl(ffff800000026d00,80585750,ffff800020c3d830,82,ffff800020b42270) at wsmux_do_ioctl+0x583 sys/dev/wscons/wsmux.c:528 VOP_IOCTL(fffffd807d5bf2f0,80585750,ffff800020c3d830,82,fffffd807f7c7a80,ffff800020b42270) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8068175ef8,80585750,ffff800020c3d830,ffff800020b42270) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42270,ffff800020c3d978,ffff800020c3d960) at sys_ioctl+0x646 syscall(ffff800020c3da10) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c3da10) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff80,0,3,a0bb0132010) at Xsyscall+0x128 end of kernel end trace frame: 0xa0e6c5f38a0, 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(ffff8000019705d0,1,ffffffff81f354ca,207,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff8000019705d0,1,ffffffff81f354ca,207,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff8000019705c0,ffffffff81f354ca,207) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_do_ioctl(ffff800001970500,80585750,ffff800020c3d830,82,ffff800020b42270) at wsmux_do_ioctl+0x4ef wsmux_do_ioctl(ffff800000026d00,80585750,ffff800020c3d830,82,ffff800020b42270) at wsmux_do_ioctl+0x583 sys/dev/wscons/wsmux.c:528 VOP_IOCTL(fffffd807d5bf2f0,80585750,ffff800020c3d830,82,fffffd807f7c7a80,ffff800020b42270) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8068175ef8,80585750,ffff800020c3d830,ffff800020b42270) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42270,ffff800020c3d978,ffff800020c3d960) at sys_ioctl+0x646 syscall(ffff800020c3da10) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c3da10) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff80,0,3,a0bb0132010) at Xsyscall+0x128 end of kernel end trace frame: 0xa0e6c5f38a0, count: -10 ddb{1}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c3d3e0 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800000947000 rax 0xffff80000005ce00 r8 0xffffffff81316553 kprintf+0x183 r9 0x1 r10 0x25 r11 0x4319ed50c13e2553 r12 0xffffffff81f354ca substchar+0x955e r13 0x207 r14 0xffffffff81f25297 apollo_udma33_tim+0x16e4 r15 0xffffffff81f354ca substchar+0x955e rip 0xffffffff81264218 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c3d3d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=201831 stat=onproc flags process=0 proc=4000000 pri=69, usrpri=69, nice=20 forw=0xffffffffffffffff, list=0xffff800020b43080,0xffffffff82334d38 process=0xffff800020b44d30 user=0xffff800020c38000, vmspace=0xfffffd807f00db40 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 51583 504441 47346 0 2 0 syz-executor.0 *51583 201831 47346 0 7 0x4000000 syz-executor.0 12419 187046 74421 0 7 0 syz-executor.1 12419 195305 74421 0 3 0x4000000 ffs_fsync syz-executor.1 9418 169392 0 0 3 0x14200 bored sosplice 74421 475924 81261 0 3 0x82 nanosleep syz-executor.1 47346 329637 81261 0 3 0x82 nanosleep syz-executor.0 81261 449667 9648 0 3 0x82 thrsleep syz-fuzzer 81261 466137 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 303474 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 387188 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 111150 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 131787 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 275032 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 293444 9648 0 3 0x4000082 thrsleep syz-fuzzer 81261 12782 9648 0 3 0x4000082 kqread syz-fuzzer 81261 281556 9648 0 3 0x4000082 thrsleep syz-fuzzer 9648 246898 19327 0 3 0x10008a pause ksh 19327 306176 48573 0 3 0x92 select sshd 60488 193944 1 0 3 0x100083 ttyin getty 48573 130010 1 0 3 0x80 select sshd 4704 356184 89469 73 2 0x100090 syslogd 89469 312168 1 0 3 0x100082 netio syslogd 13736 343025 1 77 3 0x100090 poll dhclient 21936 371968 1 0 3 0x80 poll dhclient 44213 247208 0 0 2 0x14200 zerothread 15060 231311 0 0 3 0x14200 aiodoned aiodoned 28378 148872 0 0 3 0x14200 syncer update 95178 278322 0 0 3 0x14200 cleaner cleaner 76442 265626 0 0 3 0x14200 reaper reaper 59491 84830 0 0 3 0x14200 pgdaemon pagedaemon 21662 379294 0 0 3 0x14200 bored crynlk 29292 222286 0 0 3 0x14200 bored crypto 68248 457777 0 0 3 0x40014200 acpi0 acpi0 44185 284322 0 0 3 0x40014200 idle1 87920 48453 0 0 3 0x14200 bored softnet 14474 77412 0 0 3 0x14200 bored systqmp 9872 278212 0 0 3 0x14200 bored systq 90317 9936 0 0 3 0x40014200 bored softclock 81715 445484 0 0 3 0x40014200 idle0 1 375249 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 51583 (syz-executor.0) thread 0xffff800020b42270 (201831) shared rwlock wsmuxlk r = 0 (0xffff800000026dd0) locked @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:519 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 wsmux_do_ioctl+0x4ef #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 12419 (syz-executor.1) thread 0xffff800020b42e28 (195305) exclusive rrwlock inode r = 0 (0xfffffd806d1bf810) 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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9477 6343K 6344K 78643K 10637 0 0 pcb 23 9K 10K 78643K 133 0 0 rtable 100 3K 4K 78643K 205 0 0 ifaddr 43 11K 11K 78643K 61 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 15 0 0 iov 0 0K 12K 78643K 14 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1200 75K 75K 78643K 1288 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 4 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 6 0K 0K 78643K 6 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 6 17K 25K 78643K 143 0 0 proc 41 38K 70K 78643K 269 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 18 0 0 in_multi 33 2K 2K 78643K 37 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 54 238K 238K 78643K 54 0 0 exec 0 0K 1K 78643K 170 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 79 20K 20K 78643K 1201 0 0 UVM aobj 14 2K 2K 78643K 14 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 9 0 0 NDP 7 0K 0K 78643K 16 0 0 temp 115 2357K 2421K 78643K 3172 0 0 kqueue 0 0K 0K 78643K 3 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 79 0 72 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 tcpcb 544 26 0 22 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 2 0 2 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 186 0 0 12 0 12 12 0 8 0 art_table 32 187 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 7 0 2 1 0 1 1 0 8 0 semapl 112 4 0 0 1 0 1 1 0 8 0 shmpl 112 12 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1668 0 263 46 0 46 46 0 8 0 ffsino 272 1668 0 263 95 1 94 95 0 8 0 nchpl 144 2074 0 451 61 0 61 61 0 8 0 uvmvnodes 72 1737 0 0 32 0 32 32 0 8 0 vnodes 200 1737 0 0 92 0 92 92 0 8 0 namei 1024 5115 0 5115 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 1 0 1 1 0 1 1 0 8 1 scxspl 192 5091 0 5089 6 4 2 5 0 8 1 sigapl 432 311 0 297 2 0 2 2 0 8 0 futexpl 56 1307 0 1307 1 0 1 1 0 8 1 knotepl 112 95 0 68 3 1 2 2 0 8 1 kqueuepl 104 42 0 40 1 0 1 1 0 8 0 pipepl 112 216 0 197 1 0 1 1 0 8 0 fdescpl 488 312 0 297 3 1 2 3 0 8 0 filepl 152 1635 0 1538 6 1 5 5 0 8 1 lockfpl 104 35 0 34 2 1 1 1 0 8 0 lockfspl 32 63 0 62 2 1 1 1 0 8 0 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 96 170 0 163 1 0 1 1 0 8 0 zombiepl 144 297 0 297 1 0 1 1 0 8 1 processpl 840 327 0 297 4 0 4 4 0 8 0 procpl 600 638 0 597 4 0 4 4 0 8 0 sosppl 128 4 0 4 1 0 1 1 0 8 1 sockpl 384 185 0 168 3 0 3 3 0 8 1 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 111 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 5412 0 1013 275 0 275 275 0 8 0 anonpl 16 36818 0 29045 37 2 35 36 0 125 3 amapchunkpl 152 1437 0 1348 6 1 5 6 0 158 0 amappl16 192 1149 0 740 24 1 23 24 0 8 2 amappl15 184 4 0 2 2 1 1 1 0 8 0 amappl14 176 72 0 68 2 1 1 1 0 8 0 amappl13 168 29 0 25 1 0 1 1 0 8 0 amappl12 160 6 0 6 1 1 0 1 0 8 0 amappl11 152 180 0 171 1 0 1 1 0 8 0 amappl10 144 187 0 181 1 0 1 1 0 8 0 amappl9 136 349 0 345 1 0 1 1 0 8 0 amappl8 128 134 0 118 1 0 1 1 0 8 0 amappl7 120 38 0 33 1 0 1 1 0 8 0 amappl6 112 114 0 106 1 0 1 1 0 8 0 amappl5 104 135 0 123 1 0 1 1 0 8 0 amappl4 96 268 0 246 2 1 1 2 0 8 0 amappl3 88 135 0 129 1 0 1 1 0 8 0 amappl2 80 1878 0 1818 2 0 2 2 0 8 0 amappl1 72 15138 0 14709 24 14 10 19 0 8 0 amappl 72 841 0 806 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 13 0 0 1 0 1 1 0 8 0 uaddrrnd 24 312 0 297 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 312 0 297 1 0 1 1 0 8 0 vmmpekpl 168 6397 0 6376 2 0 2 2 0 8 0 vmmpepl 168 39635 0 38213 79 15 64 70 0 357 2 vmsppl 360 311 0 297 2 0 2 2 0 8 0 pdppl 4096 631 0 594 6 1 5 6 0 8 0 pvpl 32 133626 0 122773 103 4 99 100 0 265 11 pmappl 224 311 0 297 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 420 0 4 12 0 12 12 0 8 0