login: witness: lock order reversal: 1st 0xffff800020b3b228 &pr->ps_mtx (&pr->ps_mtx) 2nd 0xffffffff8236c9d8 &sched_lock (&sched_lock) lock order "&sched_lock"(sched_lock) -> "&pr->ps_mtx"(mutex) first seen at: #0 witness_checkorder+0x6a7 sys/kern/subr_witness.c:877 #1 mtx_enter+0x3a sys/kern/kern_lock.c:265 #2 tuagg+0x32 sys/kern/kern_resource.c:360 #3 mi_switch+0x1c7 x86_atomic_clearbits_u32 sys/arch/amd64/compile/SYZKALLER/obj/machine/atomic.h:298 [inline] #3 mi_switch+0x1c7 sys/kern/sched_bsd.c:392 #4 sleep_finish+0x110 sys/kern/kern_synch.c:303 #5 msleep+0x1af sleep_finish_timeout sys/kern/kern_synch.c:327 [inline] #5 msleep+0x1af sleep_finish_all sys/kern/kern_synch.c:157 [inline] #5 msleep+0x1af sys/kern/kern_synch.c:220 #6 scsi_xs_sync+0x14f sys/scsi/scsi_base.c:1339 #7 scsi_start+0x86 sys/scsi/scsi_base.c:938 #8 sdopen+0x22b sys/scsi/sd.c:400 #9 spec_open+0x41c sys/kern/spec_vnops.c:158 #10 VOP_OPEN+0x6a sys/kern/vfs_vops.c:153 #11 sr_meta_native_bootprobe+0xd3 sys/dev/softraid.c:1038 #12 sr_boot_assembly+0x1aa sys/dev/softraid.c:1202 #13 sr_attach+0x183 sys/dev/softraid.c:1822 #14 config_attach+0x347 sys/kern/subr_autoconf.c:404 #15 main+0x6de sys/kern/init_main.c:483 #16 longmode_hi+0x95 lock order "&pr->ps_mtx"(mutex) -> "&sched_lock"(sched_lock) first seen at: #0 witness_checkorder+0x6a7 sys/kern/subr_witness.c:877 #1 __mp_lock+0xa1 #2 schedclock+0x99 sys/kern/sched_bsd.c:547 #3 hardclock+0x1d8 sys/kern/kern_clock.c:174 #4 lapic_clockintr+0x44 sys/arch/amd64/amd64/lapic.c:425 #5 Xresume_lapic_ltimer+0x26 #6 tuagg+0xc9 #7 exit1+0x6e5 sys/kern/kern_exit.c:292 #8 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #9 userret+0x347 sys/kern/kern_sig.c:1907 #10 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #10 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #11 Xsyscall+0x128 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:398 witness_checkorder(ffffffff8236c9d8,9,0) at witness_checkorder+0xffc witness_debugger sys/kern/subr_witness.c:2504 [inline] witness_checkorder(ffffffff8236c9d8,9,0) at witness_checkorder+0xffc sys/kern/subr_witness.c:1084 __mp_lock(ffffffff8236c7d0) at __mp_lock+0xa1 schedclock(ffff800020b39c38) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800022deecb0) at hardclock+0x1d8 sys/kern/kern_clock.c:174 lapic_clockintr(0,0) at lapic_clockintr+0x44 sys/arch/amd64/amd64/lapic.c:425 Xresume_lapic_ltimer(9,0,ffff800020b3b168,0,0,ffff800020b39c38) at Xresume_lapic_ltimer+0x26 tuagg(ffff800020b39c38,0) at tuagg+0xc9 exit1(ffff800020b39c38,0,3) at exit1+0x6e5 sys/kern/kern_exit.c:292 single_thread_check(ffff800020b39c38,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b39c38) at userret+0x347 sys/kern/kern_sig.c:1907 syscall(ffff800022deeff0) at syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(ffff800022deeff0) at syscall+0x614 sys/arch/amd64/amd64/trap.c:596 Xsyscall(6,4,b62e6ae2180,53,0,b6253df3600) at Xsyscall+0x128 end of kernel end trace frame: 0xb62cb89ea70, count: -13 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821c7a20 __sancov_gen_cov_switch_values.122 rbp 0xffff800022deeab0 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff813b9985 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xde3facce460162bb r12 0xfffffd8002662340 r13 0xc r14 0xffffffff8230d670 w_lodata+0x4c030 r15 0xffffffff823187d0 w_lodata+0x57190 rip 0xffffffff81e8beb8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022deeaa0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=79686 stat=dead flags process=1010 proc=4082000 pri=50, usrpri=72, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3b168 user=0xffff800022dea000, vmspace=0xfffffd807effe168 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 76962 332655 78451 32767 3 0x3010 suspend syz-executor.0 76962 269003 78451 32767 7 0x4081010 syz-executor.0 6015 104117 4229 32767 3 0x90 nanosleep syz-executor.1 6015 318157 4229 32767 3 0x4000090 ttyin syz-executor.1 6015 282959 4229 32767 3 0x4000090 fsleep syz-executor.1 4229 462048 101 32767 3 0x90 nanosleep syz-executor.1 101 229285 43798 0 3 0x82 wait syz-executor.1 78451 95687 27283 32767 3 0x90 nanosleep syz-executor.0 27283 53079 43798 0 3 0x82 wait syz-executor.0 11810 475075 0 0 3 0x14200 bored sosplice 43798 487627 74314 0 3 0x82 thrsleep syz-fuzzer 43798 98694 74314 0 3 0x4000082 nanosleep syz-fuzzer 43798 184693 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 230781 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 79792 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 111409 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 494695 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 337504 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 437918 74314 0 3 0x4000082 thrsleep syz-fuzzer 43798 230311 74314 0 3 0x4000082 kqread syz-fuzzer 74314 158058 98451 0 3 0x10008a pause ksh 98451 264267 11837 0 3 0x92 select sshd 53378 365784 1 0 3 0x100083 ttyin getty 11837 302104 1 0 3 0x80 select sshd 31323 117445 45781 73 2 0x100090 syslogd 45781 157949 1 0 3 0x100082 netio syslogd 74591 398594 1 77 3 0x100090 poll dhclient 22749 206219 1 0 3 0x80 poll dhclient 42005 103325 0 0 3 0x14200 pgzero zerothread 2530 161666 0 0 3 0x14200 aiodoned aiodoned 43044 54537 0 0 3 0x14200 syncer update 89648 233420 0 0 3 0x14200 cleaner cleaner 31215 44273 0 0 3 0x14200 reaper reaper 56138 323591 0 0 3 0x14200 pgdaemon pagedaemon 5557 287306 0 0 3 0x14200 bored crynlk 53096 222468 0 0 3 0x14200 bored crypto 29037 68858 0 0 3 0x40014200 acpi0 acpi0 16899 69537 0 0 3 0x40014200 idle1 94215 351089 0 0 3 0x14200 bored softnet 3711 464357 0 0 3 0x14200 bored systqmp 16122 461273 0 0 3 0x14200 bored systq 65568 489367 0 0 3 0x40014200 bored softclock 57333 192601 0 0 3 0x40014200 idle0 80215 2720 0 0 3 0x14200 bored smr 1 68639 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive mutex &pr->ps_mtx r = 0 (0xffff800020b3b228) #0 witness_lock+0x52e sys/kern/subr_witness.c:1161 #1 mtx_enter_try+0x102 #2 mtx_enter+0x4b sys/kern/kern_lock.c:266 #3 tuagg+0x32 sys/kern/kern_resource.c:360 #4 exit1+0x6e5 sys/kern/kern_exit.c:292 #5 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #6 userret+0x347 sys/kern/kern_sig.c:1907 #7 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #7 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #8 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9458 6321K 6321K 78643K 10595 0 0 pcb 23 9K 11K 78643K 342 0 0 rtable 105 3K 3K 78643K 639 0 0 ifaddr 36 10K 10K 78643K 99 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 35 0 0 iov 0 0K 16K 78643K 30 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 1468 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 9 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 46 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 8 25K 33K 78643K 542 0 0 sigio 0 0K 0K 78643K 8 0 0 proc 41 38K 70K 78643K 719 0 0 subproc 34 2K 2K 78643K 204 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 80 0 0 in_multi 33 2K 2K 78643K 156 0 0 ether_multi 1 0K 0K 78643K 3 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 336 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 94 21K 30K 78643K 2589 0 0 UVM aobj 30 2K 2K 78643K 34 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 16 0 0 NDP 5 0K 0K 78643K 39 0 0 temp 107 2726K 2791K 78643K 5242 0 0 kqueue 0 0K 0K 78643K 2 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 26 0 20 1 0 1 1 0 8 0 inpcbpl 280 261 0 252 1 0 1 1 0 8 0 plimitpl 152 60 0 50 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 155 0 111 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 90 0 86 1 0 1 1 0 8 0 nd6 48 36 0 30 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 636 0 448 12 0 12 12 0 8 0 art_table 32 637 0 448 2 0 2 2 0 8 0 art_node 16 154 0 114 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 7 1 0 1 1 0 8 0 semapl 112 44 0 34 1 0 1 1 0 8 0 shmpl 112 32 0 4 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1919 0 496 47 0 47 47 0 8 0 ffsino 272 1919 0 496 96 0 96 96 0 8 0 nchpl 144 2658 0 1039 61 0 61 61 0 8 0 uvmvnodes 72 2132 0 0 39 0 39 39 0 8 0 vnodes 200 2132 0 0 113 0 113 113 0 8 0 namei 1024 8391 0 8391 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 6590 0 6590 8 7 1 6 0 8 1 sigapl 432 683 0 667 4 2 2 3 0 8 0 futexpl 56 3813 0 3812 1 0 1 1 0 8 0 knotepl 112 333 0 314 1 0 1 1 0 8 0 kqueuepl 104 93 0 91 1 0 1 1 0 8 0 pipepl 112 440 0 421 3 2 1 2 0 8 0 fdescpl 488 684 0 667 3 0 3 3 0 8 0 filepl 152 3729 0 3627 7 2 5 6 0 8 1 lockfpl 104 58 0 58 2 1 1 1 0 8 1 lockfspl 48 20 0 20 2 1 1 1 0 8 1 sessionpl 112 27 0 17 1 0 1 1 0 8 0 pgrppl 48 30 0 20 1 0 1 1 0 8 0 ucredpl 96 886 0 877 1 0 1 1 0 8 0 zombiepl 144 668 0 667 2 1 1 1 0 8 0 processpl 888 700 0 667 4 0 4 4 0 8 0 procpl 600 1506 0 1460 4 0 4 4 0 8 0 srpgc 64 60 0 60 2 1 1 1 0 8 1 sosppl 128 9 0 9 1 1 0 1 0 8 0 sockpl 384 598 0 579 4 1 3 4 0 8 1 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 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 256 178 0 0 11 0 11 11 0 8 0 bufpl 256 6038 0 1159 305 0 305 305 0 8 0 anonpl 16 67797 0 62263 42 8 34 34 0 125 8 amapchunkpl 152 5544 0 5453 20 11 9 18 0 158 5 amappl16 192 1997 0 1687 18 1 17 17 0 8 1 amappl15 184 54 0 54 1 0 1 1 0 8 1 amappl14 176 150 0 147 2 1 1 1 0 8 0 amappl13 168 26 0 26 3 3 0 1 0 8 0 amappl12 160 90 0 89 1 0 1 1 0 8 0 amappl11 152 152 0 132 1 0 1 1 0 8 0 amappl10 144 116 0 115 1 0 1 1 0 8 0 amappl9 136 725 0 722 1 0 1 1 0 8 0 amappl8 128 271 0 253 1 0 1 1 0 8 0 amappl7 120 93 0 84 1 0 1 1 0 8 0 amappl6 112 132 0 120 1 0 1 1 0 8 0 amappl5 104 235 0 225 1 0 1 1 0 8 0 amappl4 96 748 0 722 1 0 1 1 0 8 0 amappl3 88 317 0 307 1 0 1 1 0 8 0 amappl2 80 3865 0 3788 4 2 2 3 0 8 0 amappl1 72 25990 0 25517 23 13 10 19 0 8 0 amappl 80 1880 0 1842 1 0 1 1 0 84 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 33 0 4 1 0 1 1 0 8 0 uaddrrnd 24 684 0 667 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 684 0 667 1 0 1 1 0 8 0 vmmpekpl 168 9508 0 9482 2 0 2 2 0 8 0 vmmpepl 168 81755 0 80256 88 20 68 74 0 357 2 vmsppl 360 683 0 667 2 0 2 2 0 8 0 pdppl 4096 1376 0 1334 6 0 6 6 0 8 0 pvpl 32 229322 0 220495 122 24 98 102 0 265 23 pmappl 232 683 0 667 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 456 0 3 13 0 13 13 0 8 0