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(ffff800000026dd0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff800000026dd0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926 _rw_enter_read(ffff800000026dc0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff800000026d00,ffff800001970e50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff800000026d00,ffff800001970e50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmux_attach_sc(ffff800001970e00,ffff800000026d00) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:670 VOP_IOCTL(fffffd807167d888,80085761,ffff800020c4f2d0,f,fffffd807f7c7720,ffff800020b424c8) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd807176a7d8,80085761,ffff800020c4f2d0,ffff800020b424c8) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b424c8,ffff800020c4f418,ffff800020c4f400) at sys_ioctl+0x646 syscall(ffff800020c4f4b0) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c4f4b0) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,6009de5d010) at Xsyscall+0x128 end of kernel end trace frame: 0x6035a186f20, 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(ffff800000026dd0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 witness_debugger sys/kern/subr_witness.c:2650 [inline] witness_checkorder(ffff800000026dd0,1,ffffffff81f36129,f5,0) at witness_checkorder+0xe19 sys/kern/subr_witness.c:926 _rw_enter_read(ffff800000026dc0,ffffffff81f36129,f5) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102 wsmux_mux_open(ffff800000026d00,ffff800001970e50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:246 [inline] wsmux_mux_open(ffff800000026d00,ffff800001970e50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:228 wsmux_attach_sc(ffff800001970e00,ffff800000026d00) at wsmux_attach_sc+0x180 sys/dev/wscons/wsmux.c:670 VOP_IOCTL(fffffd807167d888,80085761,ffff800020c4f2d0,f,fffffd807f7c7720,ffff800020b424c8) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd807176a7d8,80085761,ffff800020c4f2d0,ffff800020b424c8) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b424c8,ffff800020c4f418,ffff800020c4f400) at sys_ioctl+0x646 syscall(ffff800020c4f4b0) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c4f4b0) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff86,0,3,6009de5d010) at Xsyscall+0x128 end of kernel end trace frame: 0x6035a186f20, count: -10 ddb{0}> show registers rdi 0 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c4ef00 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b49000 rax 0xffff800001747c80 r8 0xffffffff8155ffb3 kprintf+0x183 r9 0x1 r10 0x25 r11 0x87dfebacd650e454 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 0xffff800020c4eef0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=51517 stat=onproc flags process=0 proc=4000000 pri=67, usrpri=67, nice=20 forw=0xffffffffffffffff, list=0xffff800020b42bd0,0xffffffff8233fe30 process=0xffff800020b446a0 user=0xffff800020c4a000, vmspace=0xfffffd807efff708 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 30310 44756 24418 0 2 0 syz-executor.1 *30310 51517 24418 0 7 0x4000000 syz-executor.1 63808 113419 0 0 3 0x14200 bored sosplice 24418 293691 1486 0 3 0x82 nanosleep syz-executor.1 38721 235049 1486 0 3 0x2 biowait syz-executor.0 1486 177181 73012 0 3 0x82 thrsleep syz-fuzzer 1486 10252 73012 0 3 0x4000082 nanosleep syz-fuzzer 1486 320633 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 269166 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 483687 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 400727 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 517516 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 499541 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 183492 73012 0 3 0x4000082 thrsleep syz-fuzzer 1486 311232 73012 0 3 0x4000082 kqread syz-fuzzer 1486 422054 73012 0 3 0x4000082 thrsleep syz-fuzzer 73012 299253 14578 0 3 0x10008a pause ksh 14578 333513 42262 0 3 0x92 select sshd 85177 514117 1 0 3 0x100083 ttyin getty 42262 73043 1 0 3 0x80 select sshd 49454 258464 33401 73 7 0x100090 syslogd 33401 223616 1 0 3 0x100082 netio syslogd 22656 403712 1 77 3 0x100090 poll dhclient 93791 176008 1 0 3 0x80 poll dhclient 86892 301896 0 0 3 0x14200 pgzero zerothread 2041 392862 0 0 3 0x14200 aiodoned aiodoned 66224 14356 0 0 3 0x14200 syncer update 62214 65659 0 0 3 0x14200 cleaner cleaner 87576 84978 0 0 3 0x14200 reaper reaper 24471 467322 0 0 3 0x14200 pgdaemon pagedaemon 81740 300282 0 0 3 0x14200 bored crynlk 8002 248897 0 0 3 0x14200 bored crypto 82459 360144 0 0 3 0x40014200 acpi0 acpi0 63044 298055 0 0 3 0x40014200 idle1 72641 434925 0 0 3 0x14200 bored softnet 53901 198458 0 0 3 0x14200 bored systqmp 74108 509947 0 0 3 0x14200 bored systq 18902 245180 0 0 3 0x40014200 bored softclock 2609 32380 0 0 3 0x40014200 idle0 1 10298 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 30310 (syz-executor.1) thread 0xffff800020b424c8 (51517) exclusive rwlock wsmuxlk r = 0 (0xffff800001970ed0) 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 Process 38721 (syz-executor.0) thread 0xffff800020b24260 (235049) exclusive rrwlock inode r = 0 (0xfffffd8071767d60) 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 (0xfffffd806a1e12b8) 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 9464 6353K 6353K 78643K 10614 0 0 pcb 23 9K 9K 78643K 121 0 0 rtable 100 3K 4K 78643K 200 0 0 ifaddr 35 10K 11K 78643K 53 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 17 0 0 iov 0 0K 16K 78643K 6 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1194 75K 75K 78643K 1302 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 8 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 29 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 25K 78643K 196 0 0 sigio 0 0K 0K 78643K 8 0 0 proc 41 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 19 0 0 in_multi 33 2K 2K 78643K 36 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 181 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 83 20K 29K 78643K 1364 0 0 UVM aobj 22 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 10 0 0 NDP 5 0K 0K 78643K 14 0 0 temp 85 2353K 2420K 78643K 3242 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 280 127 0 120 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 tcpcb 544 41 0 37 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 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 5 0 0 1 0 1 1 0 8 0 semapl 112 27 0 17 1 0 1 1 0 8 0 shmpl 112 20 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1767 0 360 46 0 46 46 0 8 0 ffsino 272 1767 0 360 95 0 95 95 0 8 0 nchpl 144 2242 0 620 61 0 61 61 0 8 0 uvmvnodes 72 1819 0 0 34 0 34 34 0 8 0 vnodes 200 1819 0 0 96 0 96 96 0 8 0 namei 1024 6119 0 6118 2 1 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 5444 0 5443 9 8 1 6 0 8 0 sigapl 432 364 0 351 2 0 2 2 0 8 0 futexpl 56 2204 0 2204 1 0 1 1 0 8 1 knotepl 112 99 0 72 2 1 1 2 0 8 0 kqueuepl 104 48 0 46 1 0 1 1 0 8 0 pipepl 112 258 0 239 2 1 1 1 0 8 0 fdescpl 488 365 0 351 3 1 2 3 0 8 0 filepl 152 2049 0 1954 6 1 5 5 0 8 1 lockfpl 104 99 0 99 2 1 1 1 0 8 1 lockfspl 32 120 0 120 2 1 1 1 0 8 1 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 20 0 10 1 0 1 1 0 8 0 ucredpl 96 396 0 389 1 0 1 1 0 8 0 zombiepl 144 351 0 351 2 1 1 1 0 8 1 processpl 840 380 0 351 4 0 4 4 0 8 0 procpl 600 784 0 744 4 0 4 4 0 8 0 sockpl 384 219 0 202 3 0 3 3 0 8 1 mcl64k 65536 1 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 112 0 0 13 0 13 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 131 0 0 8 0 8 8 0 8 0 bufpl 256 5463 0 1013 279 0 279 279 0 8 0 anonpl 16 44771 0 37052 41 1 40 40 0 125 8 amapchunkpl 152 2063 0 1959 10 0 10 10 0 158 4 amappl16 192 1253 0 863 21 0 21 21 0 8 1 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 9 0 7 2 1 1 1 0 8 0 amappl13 168 30 0 25 1 0 1 1 0 8 0 amappl12 160 100 0 97 2 1 1 1 0 8 0 amappl11 152 182 0 173 1 0 1 1 0 8 0 amappl10 144 238 0 234 2 1 1 1 0 8 0 amappl9 136 352 0 349 1 0 1 1 0 8 0 amappl8 128 131 0 115 1 0 1 1 0 8 0 amappl7 120 37 0 32 1 0 1 1 0 8 0 amappl6 112 53 0 45 1 0 1 1 0 8 0 amappl5 104 123 0 110 1 0 1 1 0 8 0 amappl4 96 269 0 245 2 1 1 2 0 8 0 amappl3 88 219 0 212 1 0 1 1 0 8 0 amappl2 80 2387 0 2334 2 0 2 2 0 8 0 amappl1 72 16323 0 15908 24 14 10 19 0 8 0 amappl 72 995 0 958 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 0 1 0 1 1 0 8 0 uaddrrnd 24 365 0 351 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 365 0 351 1 0 1 1 0 8 0 vmmpekpl 168 6740 0 6718 2 0 2 2 0 8 0 vmmpepl 168 44921 0 43589 85 21 64 71 0 357 4 vmsppl 360 364 0 351 2 0 2 2 0 8 0 pdppl 4096 738 0 702 6 1 5 6 0 8 0 pvpl 32 150123 0 139443 115 7 108 108 0 265 19 pmappl 224 364 0 351 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 426 0 4 13 0 13 13 0 8 0