witness: lock order reversal: 1st 0xffff800020b3a448 &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 calcru+0x7 sys/kern/kern_resource.c:417 #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(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(ffff800020b39530) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff80002505b480) 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,ffff800020b3a438,0,ffff800020b3a388,2000) at Xresume_lapic_ltimer+0x26 calcru(ffff800020b39530,0,1,ffff800020b39530) at calcru+0x7 sys/kern/kern_resource.c:417 sys_exit(ffff800020b39530,ffff80002505b600,ffff80002505b670) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff80002505b6e0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff80002505b6e0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7fffffa1a4) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffffa170, count: -11 ddb{1}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff80002505b280 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x1f5ae2f7bb4e7716 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff823354d0 w_lodata+0x46620 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002505b270 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=55342 stat=dead flags process=1018 proc=2000 pri=50, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3a388 user=0xffff800025056000, vmspace=0xfffffd807effd9d8 estcpu=29, cpticks=4, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 23097 98351 87521 32767 3 0x90 nanosleep syz-executor.1 23097 336399 87521 32767 3 0x4000090 ttyin syz-executor.1 23097 185279 87521 32767 3 0x4000090 fsleep syz-executor.1 16511 334581 87817 32767 3 0x90 nanosleep syz-executor.0 87817 441469 51517 0 3 0x82 wait syz-executor.0 87521 492100 18589 32767 3 0x90 nanosleep syz-executor.1 18589 237443 51517 0 3 0x82 wait syz-executor.1 58 192037 0 0 3 0x14200 bored sosplice 51517 280653 1810 0 3 0x82 thrsleep syz-fuzzer 51517 287648 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 473640 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 178743 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 356716 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 449736 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 201160 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 237791 1810 0 3 0x4000082 thrsleep syz-fuzzer 51517 222372 1810 0 3 0x4000082 kqread syz-fuzzer 51517 142022 1810 0 3 0x4000082 thrsleep syz-fuzzer 1810 234252 77154 0 3 0x10008a pause ksh 77154 64678 52088 0 3 0x92 select sshd 21287 242558 1 0 3 0x100083 ttyin getty 52088 302260 1 0 3 0x80 select sshd 85467 323818 14152 73 7 0x100090 syslogd 14152 172558 1 0 3 0x100082 netio syslogd 36827 139562 1 77 3 0x100090 poll dhclient 63052 440973 1 0 3 0x80 poll dhclient 91337 284656 0 0 3 0x14200 pgzero zerothread 29560 478342 0 0 3 0x14200 aiodoned aiodoned 66566 409637 0 0 3 0x14200 syncer update 33304 464091 0 0 3 0x14200 cleaner cleaner 25185 49734 0 0 3 0x14200 reaper reaper 45872 425084 0 0 3 0x14200 pgdaemon pagedaemon 19948 514423 0 0 3 0x14200 bored crynlk 87813 91595 0 0 3 0x14200 bored crypto 465 170582 0 0 3 0x40014200 acpi0 acpi0 77891 36447 0 0 3 0x40014200 idle1 93490 514301 0 0 3 0x14200 bored softnet 4360 481946 0 0 3 0x14200 bored systqmp 62590 425656 0 0 3 0x14200 bored systq 97798 129436 0 0 3 0x40014200 bored softclock 47139 506498 0 0 3 0x40014200 idle0 7788 289291 0 0 3 0x14200 bored smr 1 181214 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 (0xffff800020b3a448) #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 9460 6321K 6321K 78643K 10717 0 0 pcb 23 9K 11K 78643K 1029 0 0 rtable 105 3K 3K 78643K 1710 0 0 ifaddr 36 11K 11K 78643K 246 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 80 0 0 iov 1 16K 16K 78643K 125 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 2162 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 3 5K 5K 78643K 31 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 159 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 7 21K 33K 78643K 2031 0 0 sigio 0 0K 0K 78643K 13 0 0 proc 41 38K 70K 78643K 1849 0 0 subproc 34 2K 2K 78643K 612 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 229 0 0 in_multi 33 2K 2K 78643K 456 0 0 ether_multi 1 0K 0K 78643K 15 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 60 265K 265K 78643K 60 0 0 exec 0 0K 1K 78643K 703 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 7608 0 0 UVM aobj 85 3K 3K 78643K 101 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 91 0 0 NDP 5 0K 0K 78643K 111 0 0 temp 120 2730K 2798K 78643K 11170 0 0 kqueue 0 0K 0K 78643K 29 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 74 0 68 1 0 1 1 0 8 0 inpcbpl 280 954 0 947 1 0 1 1 0 8 0 plimitpl 152 174 0 165 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 419 0 375 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 367 0 363 1 0 1 1 0 8 0 nd6 48 108 0 102 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1715 0 1523 15 3 12 13 0 8 0 art_table 32 1716 0 1523 2 0 2 2 0 8 0 art_node 16 418 0 378 1 0 1 1 0 8 0 sysvmsgpl 40 13 0 5 1 0 1 1 0 8 0 semapl 112 157 0 147 1 0 1 1 0 8 0 shmpl 112 99 0 16 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3567 0 2123 47 0 47 47 0 8 0 ffsino 272 3567 0 2123 98 1 97 97 0 8 0 nchpl 144 6116 0 4494 61 0 61 61 0 8 0 uvmvnodes 72 4188 0 0 77 0 77 77 0 8 0 vnodes 200 4188 0 0 221 0 221 221 0 8 0 namei 1024 22736 0 22736 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 15698 0 15698 16 15 1 6 0 8 1 sigapl 432 2100 0 2084 4 2 2 3 0 8 0 futexpl 56 16148 0 16147 1 0 1 1 0 8 0 knotepl 112 1102 0 1083 1 0 1 1 0 8 0 kqueuepl 104 372 0 370 1 0 1 1 0 8 0 pipepl 112 1490 0 1471 5 4 1 2 0 8 0 fdescpl 488 2101 0 2085 3 0 3 3 0 8 1 filepl 152 12238 0 12135 9 4 5 6 0 8 0 lockfpl 104 355 0 355 5 4 1 1 0 8 1 lockfspl 48 105 0 105 5 4 1 1 0 8 1 sessionpl 112 51 0 41 1 0 1 1 0 8 0 pgrppl 48 80 0 70 1 0 1 1 0 8 0 ucredpl 96 3592 0 3583 1 0 1 1 0 8 0 zombiepl 144 2085 0 2084 2 1 1 1 0 8 0 processpl 888 2117 0 2084 4 0 4 4 0 8 0 procpl 600 5481 0 5437 4 0 4 4 0 8 0 srpgc 64 204 0 204 7 7 0 1 0 8 0 sosppl 128 22 0 22 7 7 0 1 0 8 0 sockpl 384 2003 0 1986 5 2 3 4 0 8 1 mcl64k 65536 10 0 0 2 0 2 2 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 6 0 0 1 0 1 1 0 8 0 mcl9k 9216 8 0 0 1 0 1 1 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 10 0 0 1 0 1 1 0 8 0 mcl2k 2048 115 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 263 0 0 12 0 12 12 0 8 0 bufpl 256 7682 0 1159 408 0 408 408 0 8 0 anonpl 16 209749 0 203634 83 45 38 40 0 125 9 amapchunkpl 152 16187 0 16095 26 21 5 9 0 158 1 amappl16 192 7775 0 7452 68 42 26 29 0 8 8 amappl15 184 299 0 298 1 0 1 1 0 8 0 amappl14 176 598 0 595 2 1 1 1 0 8 0 amappl13 168 104 0 104 2 2 0 1 0 8 0 amappl12 160 269 0 263 2 1 1 1 0 8 0 amappl11 152 419 0 404 1 0 1 1 0 8 0 amappl10 144 473 0 469 2 1 1 1 0 8 0 amappl9 136 1240 0 1237 1 0 1 1 0 8 0 amappl8 128 720 0 699 1 0 1 1 0 8 0 amappl7 120 452 0 444 1 0 1 1 0 8 0 amappl6 112 337 0 327 1 0 1 1 0 8 0 amappl5 104 597 0 581 1 0 1 1 0 8 0 amappl4 96 1843 0 1819 1 0 1 1 0 8 0 amappl3 88 623 0 611 1 0 1 1 0 8 0 amappl2 80 13534 0 13461 4 2 2 3 0 8 0 amappl1 72 64293 0 63818 25 16 9 19 0 8 0 amappl 80 6248 0 6209 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 64 100 0 16 2 0 2 2 0 8 0 uaddrrnd 24 2101 0 2084 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2101 0 2084 1 0 1 1 0 8 0 vmmpekpl 168 21067 0 21041 2 0 2 2 0 8 0 vmmpepl 168 240253 0 238727 135 58 77 84 0 357 10 vmsppl 360 2100 0 2084 2 0 2 2 0 8 0 pdppl 4096 4210 0 4168 6 0 6 6 0 8 0 pvpl 32 620128 0 610697 192 86 106 110 0 265 25 pmappl 232 2100 0 2084 4 3 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 570 0 7 17 0 17 17 0 8 0