witness: lock order reversal: 1st 0xffff800020b8c7c8 &pr->ps_mtx (&pr->ps_mtx) 2nd 0xffffffff8236e2f8 &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+0x12b tuagg_sub sys/kern/kern_resource.c:343 [inline] #6 tuagg+0x12b sys/kern/kern_resource.c:370 #7 exit1+0x6e5 sys/kern/kern_exit.c:292 #8 sys_exit+0x17 sys/kern/kern_exit.c:94 #9 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #9 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #10 Xsyscall+0x128 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:398 witness_checkorder(ffffffff8236e2f8,9,0) at witness_checkorder+0xffc witness_debugger sys/kern/subr_witness.c:2504 [inline] witness_checkorder(ffffffff8236e2f8,9,0) at witness_checkorder+0xffc sys/kern/subr_witness.c:1084 __mp_lock(ffffffff8236e0f0) at __mp_lock+0xa1 schedclock(ffff800020b39c38) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800020be3570) 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,ffffffff81786b1b,ffff800020b8c708,0,0,ffff800020b39c38) at Xresume_lapic_ltimer+0x26 tuagg(ffff800020b39c38,0) at tuagg+0x12b tuagg_sub sys/kern/kern_resource.c:343 [inline] tuagg(ffff800020b39c38,0) at tuagg+0x12b sys/kern/kern_resource.c:370 exit1(ffff800020b39c38,0,1) at exit1+0x6e5 sys/kern/kern_exit.c:292 sys_exit(ffff800020b39c38,ffff800020be3750,ffff800020be37c0) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800020be3830) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020be3830) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(0,1,0,1,0,7f7ffffe7fb4) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe7f80, count: -12 ddb{0}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff800020be3370 rbx 0x3 rdx 0xffffffff821abff0 cpu_info_full_primary+0x1ff0 rcx 0x3 rax 0xffffffff821abff0 cpu_info_full_primary+0x1ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x40797099f6adf398 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff82336e40 w_lodata+0x47f90 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020be3360 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=91815 stat=dead flags process=1018 proc=2000 pri=26, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8c708 user=0xffff800020bde000, vmspace=0xfffffd807effd2d0 estcpu=36, cpticks=21, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 2413 462829 8570 32767 2 0x10 syz-executor.1 2413 161490 8570 32767 7 0x4000010 syz-executor.1 30961 437775 6220 32767 3 0x90 nanosleep syz-executor.0 6220 94329 63627 0 3 0x82 wait syz-executor.0 8570 345952 10447 32767 3 0x90 nanosleep syz-executor.1 10447 49371 63627 0 3 0x82 wait syz-executor.1 17488 380589 0 0 3 0x14200 bored sosplice 63627 456460 51893 0 3 0x82 thrsleep syz-fuzzer 63627 434285 51893 0 3 0x4000082 nanosleep syz-fuzzer 63627 316914 51893 0 3 0x4000082 thrsleep syz-fuzzer 63627 67273 51893 0 3 0x4000082 thrsleep syz-fuzzer 63627 465962 51893 0 3 0x4000082 thrsleep syz-fuzzer 63627 185116 51893 0 3 0x4000082 kqread syz-fuzzer 63627 517426 51893 0 3 0x4000082 thrsleep syz-fuzzer 63627 119457 51893 0 3 0x4000082 thrsleep syz-fuzzer 63627 353097 51893 0 3 0x4000082 thrsleep syz-fuzzer 63627 469368 51893 0 3 0x4000082 thrsleep syz-fuzzer 51893 160303 57083 0 3 0x10008a pause ksh 57083 201037 28204 0 3 0x92 select sshd 71514 503477 1 0 3 0x100083 ttyin getty 28204 81309 1 0 3 0x80 select sshd 4301 360106 55770 73 2 0x100090 syslogd 55770 382315 1 0 3 0x100082 netio syslogd 24501 38360 1 77 3 0x100090 poll dhclient 32893 340236 1 0 3 0x80 poll dhclient 3078 293155 0 0 2 0x14200 zerothread 66438 363583 0 0 3 0x14200 aiodoned aiodoned 68039 158061 0 0 3 0x14200 syncer update 41909 614 0 0 3 0x14200 cleaner cleaner 70653 45631 0 0 3 0x14200 reaper reaper 39128 277985 0 0 3 0x14200 pgdaemon pagedaemon 58275 365728 0 0 3 0x14200 bored crynlk 15355 490551 0 0 3 0x14200 bored crypto 46445 470077 0 0 3 0x40014200 acpi0 acpi0 14722 517483 0 0 3 0x40014200 idle1 4095 157888 0 0 3 0x14200 bored softnet 49900 318868 0 0 3 0x14200 bored systqmp 62824 354099 0 0 3 0x14200 bored systq 79028 115246 0 0 3 0x40014200 bored softclock 38995 301556 0 0 3 0x40014200 idle0 78002 54505 0 0 3 0x14200 bored smr 1 427673 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive mutex &pr->ps_mtx r = 0 (0xffff800020b8c7c8) #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 sys_exit+0x17 sys/kern/kern_exit.c:94 #6 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #6 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #7 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9459 6321K 6321K 78643K 10686 0 0 pcb 23 9K 10K 78643K 688 0 0 rtable 105 3K 3K 78643K 1449 0 0 ifaddr 35 10K 10K 78643K 207 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 60 0 0 iov 0 0K 16K 78643K 96 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1208 76K 76K 78643K 1975 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 18 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 98 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 7 21K 33K 78643K 1534 0 0 sigio 0 0K 0K 78643K 19 0 0 proc 41 38K 70K 78643K 1551 0 0 subproc 34 2K 2K 78643K 510 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 242 0 0 in_multi 33 2K 2K 78643K 384 0 0 ether_multi 1 0K 0K 78643K 11 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 582 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 95 21K 31K 78643K 5947 0 0 UVM aobj 59 2K 2K 78643K 68 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 74 0 0 NDP 5 0K 0K 78643K 93 0 0 temp 120 2733K 2799K 78643K 9427 0 0 kqueue 0 0K 0K 78643K 18 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 62 0 56 1 0 1 1 0 8 0 inpcbpl 280 778 0 771 2 1 1 2 0 8 0 plimitpl 152 134 0 125 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 353 0 309 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 261 0 257 1 0 1 1 0 8 0 nd6 48 90 0 84 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1433 0 1242 13 0 13 13 0 8 1 art_table 32 1434 0 1242 2 0 2 2 0 8 0 art_node 16 352 0 312 1 0 1 1 0 8 0 sysvmsgpl 40 15 0 6 1 0 1 1 0 8 0 semapl 112 96 0 86 1 0 1 1 0 8 0 shmpl 112 66 0 9 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2981 0 1538 47 0 47 47 0 8 0 ffsino 272 2981 0 1538 97 0 97 97 0 8 0 nchpl 144 4893 0 3274 61 0 61 61 0 8 0 uvmvnodes 72 3500 0 0 64 0 64 64 0 8 0 vnodes 200 3500 0 0 185 0 185 185 0 8 0 namei 1024 17804 0 17804 4 3 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 12571 0 12571 10 9 1 6 0 8 1 sigapl 432 1621 0 1605 3 1 2 3 0 8 0 futexpl 56 12088 0 12088 3 2 1 1 0 8 1 knotepl 112 912 0 893 1 0 1 1 0 8 0 kqueuepl 104 314 0 312 1 0 1 1 0 8 0 pipepl 112 984 0 965 4 3 1 2 0 8 0 fdescpl 488 1622 0 1606 3 0 3 3 0 8 0 filepl 152 9402 0 9306 8 3 5 6 0 8 1 lockfpl 104 284 0 284 4 3 1 1 0 8 1 lockfspl 48 80 0 80 4 3 1 1 0 8 1 sessionpl 112 45 0 35 1 0 1 1 0 8 0 pgrppl 48 57 0 47 1 0 1 1 0 8 0 ucredpl 96 2725 0 2716 1 0 1 1 0 8 0 zombiepl 144 1606 0 1605 3 2 1 1 0 8 0 processpl 888 1638 0 1605 4 0 4 4 0 8 0 procpl 600 4054 0 4011 5 1 4 5 0 8 0 srpgc 64 168 0 168 6 5 1 1 0 8 1 sosppl 128 40 0 40 8 7 1 1 0 8 1 sockpl 384 1490 0 1473 5 2 3 3 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 11 0 0 2 0 2 2 0 8 0 mcl9k 9216 8 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 9 0 0 2 0 2 2 0 8 0 mcl2k2 2112 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 119 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 243 0 0 12 0 12 12 0 8 0 bufpl 256 7184 0 1159 377 0 377 377 0 8 0 anonpl 16 153029 0 146776 73 46 27 41 0 125 0 amapchunkpl 152 13128 0 13033 39 34 5 18 0 158 0 amappl16 192 6009 0 5699 52 35 17 28 0 8 0 amappl15 184 254 0 252 4 3 1 1 0 8 0 amappl14 176 353 0 350 2 1 1 1 0 8 0 amappl13 168 149 0 149 3 3 0 1 0 8 0 amappl12 160 164 0 158 1 0 1 1 0 8 0 amappl11 152 245 0 231 1 0 1 1 0 8 0 amappl10 144 368 0 363 2 1 1 1 0 8 0 amappl9 136 1136 0 1133 1 0 1 1 0 8 0 amappl8 128 613 0 596 1 0 1 1 0 8 0 amappl7 120 367 0 355 1 0 1 1 0 8 0 amappl6 112 189 0 179 1 0 1 1 0 8 0 amappl5 104 438 0 426 1 0 1 1 0 8 0 amappl4 96 1607 0 1583 1 0 1 1 0 8 0 amappl3 88 415 0 403 1 0 1 1 0 8 0 amappl2 80 10105 0 10029 4 2 2 3 0 8 0 amappl1 72 51167 0 50713 23 13 10 19 0 8 0 amappl 80 4763 0 4723 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 67 0 9 1 0 1 1 0 8 0 uaddrrnd 24 1622 0 1605 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1622 0 1605 1 0 1 1 0 8 0 vmmpekpl 168 16810 0 16778 2 0 2 2 0 8 0 vmmpepl 168 186628 0 185132 129 61 68 83 0 357 2 vmsppl 360 1621 0 1605 2 0 2 2 0 8 0 pdppl 4096 3252 0 3210 7 1 6 6 0 8 0 pvpl 32 480330 0 470130 177 89 88 109 0 265 5 pmappl 232 1621 0 1605 6 5 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 536 0 6 16 0 16 16 0 8 0