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 calcru #7 sys_exit+0x17 sys/kern/kern_exit.c:94 #8 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #8 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #9 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(ffff800020b38018) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800024e458d0) 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,ffff800020b3b218,0,ffff800020b3b168,2000) at Xresume_lapic_ltimer+0x26 calcru(ffff800020b38018,0,1,ffff800020b38018) at calcru sys_exit(ffff800020b38018,ffff800024e45a50,ffff800024e45ac0) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800024e45b30) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800024e45b30) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffde564) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffde530, count: -11 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821c7a20 __sancov_gen_cov_switch_values.122 rbp 0xffff800024e456d0 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff813b9985 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x3bf7d98163fadde4 r12 0xfffffd8002662340 r13 0xc r14 0xffffffff82301330 w_lodata+0x3fcf0 r15 0xffffffff823187d0 w_lodata+0x57190 rip 0xffffffff81e8beb8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800024e456c0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=31434 stat=dead flags process=1018 proc=2000 pri=26, usrpri=77, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3b168 user=0xffff800024e40000, vmspace=0xfffffd807effe870 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 555 21232 35878 32767 3 0x90 nanosleep syz-executor.0 35878 522278 48591 0 3 0x82 wait syz-executor.0 14386 90178 5710 32767 3 0x90 nanosleep syz-executor.1 5710 335400 48591 0 3 0x82 wait syz-executor.1 75032 122616 0 0 3 0x14200 bored sosplice 48591 503814 74508 0 3 0x82 thrsleep syz-fuzzer 48591 260391 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 34597 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 76680 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 241393 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 399574 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 292434 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 162146 74508 0 3 0x4000082 thrsleep syz-fuzzer 48591 371082 74508 0 3 0x4000082 kqread syz-fuzzer 48591 420016 74508 0 3 0x4000082 thrsleep syz-fuzzer 74508 426253 87920 0 3 0x10008a pause ksh 87920 33092 13432 0 3 0x92 select sshd 27224 318793 1 0 3 0x100083 ttyin getty 13432 164450 1 0 3 0x80 select sshd 12215 393081 68232 73 2 0x100090 syslogd 68232 237992 1 0 3 0x100082 netio syslogd 58560 127125 1 77 3 0x100090 poll dhclient 39257 369586 1 0 3 0x80 poll dhclient 67152 213305 0 0 3 0x14200 pgzero zerothread 69028 249331 0 0 3 0x14200 aiodoned aiodoned 47533 174702 0 0 3 0x14200 syncer update 27736 361719 0 0 3 0x14200 cleaner cleaner 30759 286359 0 0 7 0x14200 reaper 33236 1750 0 0 3 0x14200 pgdaemon pagedaemon 98289 514066 0 0 3 0x14200 bored crynlk 41000 4395 0 0 3 0x14200 bored crypto 35729 326063 0 0 3 0x40014200 acpi0 acpi0 99734 474387 0 0 3 0x40014200 idle1 98213 409016 0 0 3 0x14200 bored softnet 50731 363812 0 0 3 0x14200 bored systqmp 2856 267653 0 0 3 0x14200 bored systq 11899 45010 0 0 3 0x40014200 bored softclock 75295 302491 0 0 3 0x40014200 idle0 16581 462013 0 0 3 0x14200 bored smr 1 356022 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 exit1+0x722 sys/kern/kern_exit.c:300 #4 sys_exit+0x17 sys/kern/kern_exit.c:94 #5 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #5 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #6 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9459 6321K 6321K 78643K 10871 0 0 pcb 23 9K 11K 78643K 2475 0 0 rtable 105 3K 3K 78643K 3112 0 0 ifaddr 37 12K 12K 78643K 436 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 149 0 0 iov 0 0K 32K 78643K 365 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 3074 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 72 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 11 1K 1K 78643K 13 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 6 17K 33K 78643K 10187 0 0 sigio 0 0K 0K 78643K 80 0 0 proc 41 38K 70K 78643K 3317 0 0 subproc 34 2K 2K 78643K 1139 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 1214 0 0 in_multi 33 2K 2K 78643K 949 0 0 ether_multi 1 0K 0K 78643K 49 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 1201 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 108 22K 31K 78643K 29000 0 0 UVM aobj 130 4K 4K 78643K 156 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 294 0 0 NDP 7 0K 0K 78643K 204 0 0 temp 121 2734K 2826K 78643K 31313 0 0 kqueue 0 0K 0K 78643K 41 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 64 136 0 130 1 0 1 1 0 8 0 inpcbpl 280 3146 0 3139 1 0 1 1 0 8 0 plimitpl 152 3408 0 3399 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 760 0 716 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 1801 0 1797 1 0 1 1 0 8 0 nd6 48 201 0 195 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 3123 0 2931 15 3 12 13 0 8 0 art_table 32 3124 0 2931 2 0 2 2 0 8 0 art_node 16 759 0 719 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 2 1 1 0 1 0 8 0 semapl 112 11 0 2 2 1 1 1 0 8 0 shmpl 112 154 0 26 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 11991 0 10509 49 1 48 48 0 8 0 ffsino 272 11991 0 10509 100 1 99 99 0 8 0 nchpl 144 23276 0 21657 61 0 61 61 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 200 5926 0 0 312 0 312 312 0 8 0 namei 1024 93920 0 93920 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 70768 0 70768 24 23 1 6 0 8 1 sigapl 432 10163 0 10148 6 4 2 3 0 8 0 futexpl 56 66059 0 66059 1 0 1 1 0 8 1 knotepl 112 2031 0 2012 1 0 1 1 0 8 0 kqueuepl 104 752 0 750 1 0 1 1 0 8 0 pipepl 112 2746 0 2727 6 5 1 2 0 8 0 fdescpl 488 10164 0 10149 3 0 3 3 0 8 1 filepl 152 55972 0 55876 25 20 5 6 0 8 1 lockfpl 104 979 0 979 22 21 1 1 0 8 1 lockfspl 48 311 0 311 22 21 1 1 0 8 1 sessionpl 112 82 0 72 1 0 1 1 0 8 0 pgrppl 48 116 0 106 1 0 1 1 0 8 0 ucredpl 96 25825 0 25816 1 0 1 1 0 8 0 zombiepl 144 10149 0 10147 2 1 1 1 0 8 0 processpl 888 10180 0 10147 4 0 4 4 0 8 0 procpl 600 25596 0 25552 4 0 4 4 0 8 0 srpgc 64 390 0 390 14 13 1 1 0 8 1 sosppl 128 95 0 95 14 13 1 1 0 8 1 sockpl 384 5691 0 5674 17 14 3 4 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 15 0 0 2 0 2 2 0 8 0 mcl9k 9216 13 0 0 1 0 1 1 0 8 0 mcl8k 8192 16 0 0 2 0 2 2 0 8 0 mcl4k 4096 25 0 0 3 0 3 3 0 8 0 mcl2k2 2112 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 251 0 0 11 2 9 11 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 473 0 0 13 1 12 13 0 8 0 bufpl 256 20325 0 13320 439 0 439 439 0 8 0 anonpl 16 743976 0 740101 124 93 31 34 0 125 9 amapchunkpl 152 53441 0 53354 29 20 9 9 0 158 4 amappl16 192 40043 0 39848 116 101 15 23 0 8 5 amappl15 184 720 0 720 8 8 0 1 0 8 0 amappl14 176 1122 0 1118 2 1 1 1 0 8 0 amappl13 168 2087 0 2087 12 11 1 1 0 8 1 amappl12 160 1724 0 1719 1 0 1 1 0 8 0 amappl11 152 948 0 931 1 0 1 1 0 8 0 amappl10 144 3243 0 3239 2 1 1 1 0 8 0 amappl9 136 1757 0 1754 1 0 1 1 0 8 0 amappl8 128 1363 0 1318 3 1 2 2 0 8 0 amappl7 120 3259 0 3251 1 0 1 1 0 8 0 amappl6 112 860 0 842 1 0 1 1 0 8 0 amappl5 104 2542 0 2529 1 0 1 1 0 8 0 amappl4 96 10753 0 10727 1 0 1 1 0 8 0 amappl3 88 1692 0 1681 1 0 1 1 0 8 0 amappl2 80 74553 0 74488 4 2 2 3 0 8 0 amappl1 72 244742 0 244292 29 20 9 19 0 8 0 amappl 80 26801 0 26765 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 64 155 0 26 3 0 3 3 0 8 0 uaddrrnd 24 10164 0 10148 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 10164 0 10148 1 0 1 1 0 8 0 vmmpekpl 168 68394 0 68363 2 0 2 2 0 8 0 vmmpepl 168 1067785 0 1066457 180 114 66 74 0 357 5 vmsppl 360 10163 0 10148 2 0 2 2 0 8 0 pdppl 4096 20336 0 20296 6 0 6 6 0 8 1 pvpl 32 3432884 0 3425739 354 259 95 102 0 265 28 pmappl 232 10163 0 10148 11 10 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 600 0 10 17 0 17 17 0 8 0