witness: lock order reversal: 1st 0xffff800020b8d230 &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 mtx_leave+0x1b sys/kern/kern_lock.c:349 #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(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(ffff800020b38720) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800020be3640) 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,ffff800020b8d220,0,ffff800020b8d170,2000) at Xresume_lapic_ltimer+0x26 mtx_leave(ffff800020b8d220) at mtx_leave+0x1b sys/kern/kern_lock.c:349 exit1(ffff800020b38720,0,1) at exit1+0x73f sys/kern/kern_exit.c:302 sys_exit(ffff800020b38720,ffff800020be3800,ffff800020be3870) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800020be38e0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020be38e0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffe6564) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe6530, count: -12 ddb{1}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff800020be3440 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x9087c7649007b545 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff8233a3e0 w_lodata+0x4b530 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020be3430 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=273028 stat=dead flags process=1018 proc=2000 pri=50, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8d170 user=0xffff800020bde000, vmspace=0xfffffd806e8de9e0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 45145 362264 94941 32767 7 0x10 syz-executor.1 64693 508017 45961 32767 3 0x90 nanosleep syz-executor.0 45961 323372 35529 0 3 0x82 wait syz-executor.0 94941 399519 67072 32767 3 0x90 nanosleep syz-executor.1 67072 451090 35529 0 3 0x82 wait syz-executor.1 74990 271144 0 0 3 0x14200 bored sosplice 35529 239768 58190 0 3 0x82 thrsleep syz-fuzzer 35529 14744 58190 0 3 0x4000082 nanosleep syz-fuzzer 35529 454203 58190 0 3 0x4000082 thrsleep syz-fuzzer 35529 87554 58190 0 3 0x4000082 thrsleep syz-fuzzer 35529 162609 58190 0 3 0x4000082 thrsleep syz-fuzzer 35529 191019 58190 0 3 0x4000082 thrsleep syz-fuzzer 35529 480554 58190 0 3 0x4000082 thrsleep syz-fuzzer 35529 380769 58190 0 3 0x4000082 thrsleep syz-fuzzer 35529 313246 58190 0 3 0x4000082 kqread syz-fuzzer 35529 257073 58190 0 3 0x4000082 thrsleep syz-fuzzer 58190 217395 59886 0 3 0x10008a pause ksh 59886 122237 69598 0 3 0x92 select sshd 4816 519579 1 0 3 0x100083 ttyin getty 69598 94498 1 0 3 0x80 select sshd 74997 279591 78947 73 2 0x100090 syslogd 78947 190698 1 0 3 0x100082 netio syslogd 44919 73185 1 77 3 0x100090 poll dhclient 3330 192552 1 0 3 0x80 poll dhclient 70226 70448 0 0 3 0x14200 pgzero zerothread 14485 171376 0 0 3 0x14200 aiodoned aiodoned 89896 186295 0 0 3 0x14200 syncer update 49906 513099 0 0 3 0x14200 cleaner cleaner 77579 221096 0 0 3 0x14200 reaper reaper 61623 126045 0 0 3 0x14200 pgdaemon pagedaemon 52324 107725 0 0 3 0x14200 bored crynlk 2699 198351 0 0 3 0x14200 bored crypto 24307 470034 0 0 3 0x40014200 acpi0 acpi0 24108 319263 0 0 3 0x40014200 idle1 69189 210485 0 0 3 0x14200 bored softnet 12843 207522 0 0 3 0x14200 bored systqmp 91947 158369 0 0 3 0x14200 bored systq 31531 417451 0 0 3 0x40014200 bored softclock 57747 338143 0 0 3 0x40014200 idle0 90559 178736 0 0 3 0x14200 bored smr 1 27960 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 (0xffff800020b8d230) #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 10596 0 0 pcb 23 9K 10K 78643K 248 0 0 rtable 105 3K 3K 78643K 631 0 0 ifaddr 34 9K 9K 78643K 95 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 37 0 0 iov 0 0K 12K 78643K 27 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1208 76K 76K 78643K 1474 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 7 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 34 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 7 21K 33K 78643K 508 0 0 sigio 0 0K 0K 78643K 8 0 0 proc 41 38K 70K 78643K 733 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 49 0 0 in_multi 33 2K 2K 78643K 160 0 0 ether_multi 1 0K 0K 78643K 4 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 318 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 86 20K 29K 78643K 2450 0 0 UVM aobj 28 2K 2K 78643K 29 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 18 0 0 NDP 5 0K 0K 78643K 39 0 0 temp 88 2722K 2790K 78643K 5162 0 0 kqueue 0 0K 0K 78643K 12 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 280 242 0 235 1 0 1 1 0 8 0 plimitpl 152 52 0 43 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 85 0 81 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 256 628 0 440 12 0 12 12 0 8 0 art_table 32 629 0 440 2 0 2 2 0 8 0 art_node 16 154 0 114 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 3 1 0 1 1 0 8 0 semapl 112 32 0 22 1 0 1 1 0 8 0 shmpl 112 27 0 1 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1907 0 483 47 0 47 47 0 8 0 ffsino 272 1907 0 483 96 0 96 96 0 8 0 nchpl 144 2630 0 1011 61 0 61 61 0 8 0 uvmvnodes 72 2120 0 0 39 0 39 39 0 8 0 vnodes 200 2120 0 0 112 0 112 112 0 8 0 namei 1024 8153 0 8153 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 6879 0 6879 9 8 1 6 0 8 1 sigapl 432 649 0 633 3 1 2 3 0 8 0 futexpl 56 3514 0 3514 1 0 1 1 0 8 1 knotepl 112 362 0 343 1 0 1 1 0 8 0 kqueuepl 104 106 0 104 1 0 1 1 0 8 0 pipepl 112 424 0 405 3 2 1 2 0 8 0 fdescpl 488 650 0 634 3 0 3 3 0 8 0 filepl 152 3509 0 3413 7 2 5 6 0 8 1 lockfpl 104 71 0 71 2 1 1 1 0 8 1 lockfspl 48 25 0 25 2 1 1 1 0 8 1 sessionpl 112 27 0 17 1 0 1 1 0 8 0 pgrppl 48 28 0 18 1 0 1 1 0 8 0 ucredpl 96 850 0 841 1 0 1 1 0 8 0 zombiepl 144 634 0 633 2 1 1 1 0 8 0 processpl 888 666 0 633 4 0 4 4 0 8 0 procpl 600 1362 0 1320 4 0 4 4 0 8 0 srpgc 64 60 0 60 1 0 1 1 0 8 1 sosppl 128 5 0 5 2 2 0 1 0 8 0 sockpl 384 489 0 472 3 0 3 3 0 8 1 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 117 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 190 0 0 12 0 12 12 0 8 0 bufpl 256 6210 0 1159 316 0 316 316 0 8 0 anonpl 16 71194 0 66152 43 6 37 37 0 125 13 amapchunkpl 152 4514 0 4423 13 8 5 9 0 158 0 amappl16 192 2232 0 1953 29 2 27 27 0 8 12 amappl15 184 10 0 7 1 0 1 1 0 8 0 amappl14 176 111 0 109 2 1 1 1 0 8 0 amappl13 168 84 0 84 2 2 0 1 0 8 0 amappl12 160 70 0 67 1 0 1 1 0 8 0 amappl11 152 164 0 150 1 0 1 1 0 8 0 amappl10 144 118 0 115 2 1 1 1 0 8 0 amappl9 136 804 0 801 1 0 1 1 0 8 0 amappl8 128 345 0 326 1 0 1 1 0 8 0 amappl7 120 107 0 94 1 0 1 1 0 8 0 amappl6 112 119 0 111 1 0 1 1 0 8 0 amappl5 104 225 0 213 1 0 1 1 0 8 0 amappl4 96 709 0 686 1 0 1 1 0 8 0 amappl3 88 218 0 208 1 0 1 1 0 8 0 amappl2 80 3638 0 3568 4 2 2 3 0 8 0 amappl1 72 25059 0 24629 23 13 10 19 0 8 0 amappl 80 1746 0 1708 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 28 0 1 1 0 1 1 0 8 0 uaddrrnd 24 650 0 633 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 650 0 633 1 0 1 1 0 8 0 vmmpekpl 168 9366 0 9337 2 0 2 2 0 8 0 vmmpepl 168 78842 0 77419 94 20 74 74 0 357 12 vmsppl 360 649 0 633 2 0 2 2 0 8 0 pdppl 4096 1308 0 1266 6 0 6 6 0 8 0 pvpl 32 230061 0 221824 126 22 104 104 0 265 25 pmappl 232 649 0 633 4 2 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 469 0 3 14 0 14 14 0 8 0