witness: lock order reversal: 1st 0xffff800020b3ab38 &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 __sanitizer_cov_trace_pc+0x57 sys/dev/kcov.c:103 #7 exit1+0x73f sys/kern/kern_exit.c:302 #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{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(ffff800020b38720) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800020be7940) 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,ffff800020b3ab28,0,ffff800020b3aa78,ffff800020b3ab28) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x57 sys/dev/kcov.c:103 exit1(ffff800020b38720,0,1) at exit1+0x73f sys/kern/kern_exit.c:302 sys_exit(ffff800020b38720,ffff800020be7b10,ffff800020be7b80) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800020be7bf0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020be7bf0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffc2344) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc2310, count: -12 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821c7a20 __sancov_gen_cov_switch_values.122 rbp 0xffff800020be7740 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff813b9985 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x91c997f36df53c86 r12 0xfffffd8002662340 r13 0xc r14 0xffffffff82306be0 w_lodata+0x455a0 r15 0xffffffff82318670 w_lodata+0x57030 rip 0xffffffff81e8beb8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020be7730 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=500695 stat=dead flags process=1018 proc=2000 pri=50, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3aa78 user=0xffff800020be2000, vmspace=0xfffffd807effe708 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 96018 116882 6351 32767 3 0x90 nanosleep syz-executor.0 6351 51622 66492 0 3 0x82 wait syz-executor.0 52044 458120 76520 32767 2 0x10 syz-executor.1 76520 329091 66492 0 3 0x82 wait syz-executor.1 73274 25745 0 0 3 0x14200 bored sosplice 66492 376240 71868 0 3 0x82 thrsleep syz-fuzzer 66492 425700 71868 0 3 0x4000082 nanosleep syz-fuzzer 66492 519988 71868 0 3 0x4000082 thrsleep syz-fuzzer 66492 462803 71868 0 3 0x4000082 thrsleep syz-fuzzer 66492 255457 71868 0 3 0x4000082 thrsleep syz-fuzzer 66492 244315 71868 0 3 0x4000082 thrsleep syz-fuzzer 66492 80542 71868 0 3 0x4000082 thrsleep syz-fuzzer 66492 21489 71868 0 3 0x4000082 thrsleep syz-fuzzer 66492 202047 71868 0 3 0x4000082 kqread syz-fuzzer 66492 318292 71868 0 7 0x4000002 syz-fuzzer 71868 222537 82728 0 3 0x10008a pause ksh 82728 49704 84618 0 3 0x92 select sshd 23954 508339 1 0 3 0x100083 ttyin getty 84618 119091 1 0 3 0x80 select sshd 75558 65960 18181 73 2 0x100090 syslogd 18181 406241 1 0 3 0x100082 netio syslogd 61157 107379 1 77 3 0x100090 poll dhclient 41321 181067 1 0 3 0x80 poll dhclient 7119 435044 0 0 2 0x14200 zerothread 1423 167259 0 0 3 0x14200 aiodoned aiodoned 15280 339963 0 0 3 0x14200 syncer update 75691 318750 0 0 3 0x14200 cleaner cleaner 82427 472182 0 0 3 0x14200 reaper reaper 60082 398149 0 0 3 0x14200 pgdaemon pagedaemon 75131 513890 0 0 3 0x14200 bored crynlk 78523 155023 0 0 3 0x14200 bored crypto 8082 242116 0 0 3 0x40014200 acpi0 acpi0 16524 500114 0 0 3 0x40014200 idle1 34927 279443 0 0 3 0x14200 bored softnet 3943 322115 0 0 3 0x14200 bored systqmp 50124 198642 0 0 3 0x14200 bored systq 61840 135119 0 0 3 0x40014200 bored softclock 88944 67446 0 0 3 0x40014200 idle0 88921 154388 0 0 3 0x14200 bored smr 1 326329 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 (0xffff800020b3ab38) #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 10921 0 0 pcb 23 9K 10K 78643K 1490 0 0 rtable 105 3K 3K 78643K 3532 0 0 ifaddr 36 12K 12K 78643K 497 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 137 0 0 iov 0 0K 24K 78643K 179 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 3035 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 41 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 176 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 6 17K 33K 78643K 3569 0 0 sigio 0 0K 0K 78643K 50 0 0 proc 41 38K 58K 78643K 3622 0 0 subproc 34 2K 2K 78643K 1309 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 375 0 0 in_multi 33 2K 2K 78643K 944 0 0 ether_multi 1 0K 0K 78643K 23 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 1270 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 30K 78643K 12650 0 0 UVM aobj 113 3K 3K 78643K 129 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 102 0 0 NDP 5 0K 0K 78643K 234 0 0 temp 121 2734K 2810K 78643K 18981 0 0 kqueue 0 0K 0K 78643K 31 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 64 156 0 150 1 0 1 1 0 8 0 inpcbpl 280 1553 0 1546 1 0 1 1 0 8 0 plimitpl 152 308 0 299 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 870 0 826 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 560 0 556 1 0 1 1 0 8 0 nd6 48 231 0 225 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 3576 0 3382 15 2 13 13 0 8 0 art_table 32 3577 0 3382 2 0 2 2 0 8 0 art_node 16 869 0 829 1 0 1 1 0 8 0 sysvmsgpl 40 26 0 8 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 172 0 162 1 0 1 1 0 8 0 shmpl 112 127 0 16 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4847 0 3374 48 0 48 48 0 8 0 ffsino 272 4847 0 3374 101 2 99 99 0 8 0 nchpl 144 8829 0 7207 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 34694 0 34694 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 23230 0 23230 15 12 3 6 0 8 3 sigapl 432 3515 0 3500 5 3 2 3 0 8 0 futexpl 56 25193 0 25193 1 0 1 1 0 8 1 knotepl 112 2210 0 2191 1 0 1 1 0 8 0 kqueuepl 104 727 0 725 1 0 1 1 0 8 0 pipepl 112 2346 0 2327 7 6 1 2 0 8 0 fdescpl 488 3516 0 3501 3 0 3 3 0 8 1 filepl 152 19567 0 19471 13 8 5 7 0 8 1 lockfpl 104 532 0 532 5 4 1 1 0 8 1 lockfspl 48 172 0 172 5 4 1 1 0 8 1 sessionpl 112 92 0 82 1 0 1 1 0 8 0 pgrppl 48 104 0 94 1 0 1 1 0 8 0 ucredpl 96 5497 0 5488 1 0 1 1 0 8 0 zombiepl 144 3501 0 3500 2 1 1 1 0 8 0 processpl 888 3532 0 3500 4 0 4 4 0 8 0 procpl 600 8766 0 8725 4 0 4 4 0 8 0 srpgc 64 450 0 450 7 6 1 1 0 8 1 sosppl 128 55 0 55 10 10 0 1 0 8 0 sockpl 384 3107 0 3090 6 3 3 3 0 8 1 mcl64k 65536 12 0 0 2 0 2 2 0 8 0 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 22 0 0 2 0 2 2 0 8 0 mcl9k 9216 15 0 0 2 0 2 2 0 8 0 mcl8k 8192 8 0 0 1 0 1 1 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 120 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 330 0 0 12 0 12 12 0 8 0 bufpl 256 10951 0 3946 438 0 438 438 0 8 0 anonpl 16 377069 0 371490 116 77 39 43 0 125 11 amapchunkpl 152 30755 0 30663 55 50 5 18 0 158 0 amappl16 192 14755 0 14449 120 96 24 28 0 8 8 amappl15 184 291 0 291 7 7 0 1 0 8 0 amappl14 176 939 0 932 2 1 1 1 0 8 0 amappl13 168 652 0 652 7 6 1 1 0 8 1 amappl12 160 364 0 362 1 0 1 1 0 8 0 amappl11 152 583 0 564 1 0 1 1 0 8 0 amappl10 144 448 0 443 1 0 1 1 0 8 0 amappl9 136 1815 0 1811 1 0 1 1 0 8 0 amappl8 128 1223 0 1193 3 1 2 2 0 8 0 amappl7 120 551 0 541 1 0 1 1 0 8 0 amappl6 112 377 0 369 1 0 1 1 0 8 0 amappl5 104 872 0 862 1 0 1 1 0 8 0 amappl4 96 3506 0 3482 1 0 1 1 0 8 0 amappl3 88 910 0 900 1 0 1 1 0 8 0 amappl2 80 21555 0 21487 4 1 3 3 0 8 0 amappl1 72 103499 0 103067 26 16 10 19 0 8 0 amappl 80 10233 0 10196 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 64 128 0 16 2 0 2 2 0 8 0 uaddrrnd 24 3516 0 3500 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3516 0 3500 1 0 1 1 0 8 0 vmmpekpl 168 32604 0 32580 2 0 2 2 0 8 0 vmmpepl 168 396968 0 395572 134 59 75 77 0 357 10 vmsppl 360 3515 0 3500 2 0 2 2 0 8 0 pdppl 4096 7040 0 7000 6 0 6 6 0 8 1 pvpl 32 1043652 0 1034838 233 125 108 118 0 265 29 pmappl 232 3515 0 3500 6 5 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 599 0 6 17 0 17 17 0 8 0