login: witness: lock order reversal: 1st 0xffff800020b3aeb0 &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_const_cmp4 #7 mtx_leave+0x97 sys/kern/kern_lock.c:360 #8 sched_exit+0x112 sys/kern/kern_sched.c:225 #9 exit1+0x8bf sys/kern/kern_exit.c:349 #10 sys_exit+0x17 sys/kern/kern_exit.c:94 #11 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #11 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #12 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(ffff800020b38e28) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800022e02e20) 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(9,10,2,0,ffffffff821c79a0,ffff800020ab0ff0) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_const_cmp4(ffff800020b3aeb0,8) at __sanitizer_cov_trace_const_cmp4 mtx_leave(ffff800020b3aea0) at mtx_leave+0x97 sys/kern/kern_lock.c:360 sched_exit(ffff800020b38e28) at sched_exit+0x112 sys/kern/kern_sched.c:225 exit1(ffff800020b38e28,0,1) at exit1+0x8bf sys/kern/kern_exit.c:349 sys_exit(ffff800020b38e28,ffff800022e030f0,ffff800022e03160) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800022e031d0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800022e031d0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffbde24) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbddf0, count: -14 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821c7a20 __sancov_gen_cov_switch_values.122 rbp 0xffff800022e02c20 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff813b9985 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x46227b9bb1b3eb0c r12 0xfffffd8002662340 r13 0xc r14 0xffffffff8230c6a0 w_lodata+0x4b060 r15 0xffffffff823187d0 w_lodata+0x57190 rip 0xffffffff81e8beb8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022e02c10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=286997 stat=dead flags process=1018 proc=2000 pri=50, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3adf0 user=0xffff800022dfe000, vmspace=0xfffffd807effe2d0 estcpu=36, cpticks=5, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 31578 196231 10795 32767 3 0x90 nanosleep syz-executor.1 10795 466402 91610 0 3 0x82 wait syz-executor.1 38206 230343 0 0 3 0x14200 bored sosplice 91610 500093 99606 0 3 0x82 thrsleep syz-fuzzer 91610 112327 99606 0 3 0x4000082 nanosleep syz-fuzzer 91610 351100 99606 0 3 0x4000082 thrsleep syz-fuzzer 91610 74996 99606 0 3 0x4000082 thrsleep syz-fuzzer 91610 106862 99606 0 3 0x4000082 thrsleep syz-fuzzer 91610 369001 99606 0 3 0x4000082 thrsleep syz-fuzzer 91610 28501 99606 0 2 0x4000002 syz-fuzzer 91610 138792 99606 0 3 0x4000082 thrsleep syz-fuzzer 91610 6923 99606 0 3 0x4000082 kqread syz-fuzzer 91610 119948 99606 0 2 0x4000002 syz-fuzzer 99606 373415 41328 0 3 0x10008a pause ksh 41328 205363 902 0 3 0x92 select sshd 26243 39491 1 0 3 0x100083 ttyin getty 902 248534 1 0 3 0x80 select sshd 91497 263432 72135 73 2 0x100090 syslogd 72135 393762 1 0 3 0x100082 netio syslogd 90086 182820 1 77 3 0x100090 poll dhclient 74757 285823 1 0 3 0x80 poll dhclient 33616 69577 0 0 2 0x14200 zerothread 61805 196996 0 0 3 0x14200 aiodoned aiodoned 64396 468851 0 0 3 0x14200 syncer update 20964 408670 0 0 3 0x14200 cleaner cleaner 48464 397238 0 0 7 0x14200 reaper 48746 423686 0 0 3 0x14200 pgdaemon pagedaemon 47906 414786 0 0 3 0x14200 bored crynlk 68795 430597 0 0 3 0x14200 bored crypto 44293 511272 0 0 3 0x40014200 acpi0 acpi0 17445 70455 0 0 3 0x40014200 idle1 49719 379020 0 0 3 0x14200 bored softnet 71766 7477 0 0 3 0x14200 bored systqmp 61015 395454 0 0 3 0x14200 bored systq 14106 98908 0 0 3 0x40014200 bored softclock 11558 85577 0 0 3 0x40014200 idle0 98431 376226 0 0 3 0x14200 bored smr 1 146555 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 (0xffff800020b3aeb0) #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 sched_exit+0xa5 sys/kern/kern_sched.c:224 #4 exit1+0x8bf sys/kern/kern_exit.c:349 #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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9455 6319K 6321K 78643K 10592 0 0 pcb 23 9K 10K 78643K 332 0 0 rtable 83 2K 3K 78643K 603 0 0 ifaddr 29 9K 9K 78643K 91 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 31 0 0 iov 0 0K 16K 78643K 41 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1208 76K 76K 78643K 1458 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 11 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 40 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 4 9K 33K 78643K 596 0 0 sigio 0 0K 0K 78643K 12 0 0 proc 41 38K 70K 78643K 709 0 0 subproc 17 1K 2K 78643K 187 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 50 0 0 in_multi 22 1K 2K 78643K 141 0 0 ether_multi 1 0K 0K 78643K 2 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 321 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 75 12K 30K 78643K 2745 0 0 UVM aobj 25 2K 2K 78643K 33 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 20 0 0 NDP 6 0K 0K 78643K 36 0 0 temp 79 2724K 2791K 78643K 5284 0 0 kqueue 0 0K 0K 78643K 9 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 24 0 20 1 0 1 1 0 8 0 inpcbpl 280 294 0 287 1 0 1 1 0 8 0 plimitpl 152 62 0 55 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 144 0 111 2 0 2 2 0 8 1 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 2 0 2 1 1 0 1 0 8 0 tcpcb 544 98 0 94 1 0 1 1 0 8 0 nd6 48 33 0 30 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 589 0 444 12 0 12 12 0 8 2 art_table 32 590 0 444 2 0 2 2 0 8 0 art_node 16 143 0 113 1 0 1 1 0 8 0 sysvmsgpl 40 3 0 2 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 38 0 28 1 0 1 1 0 8 0 shmpl 112 31 0 8 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2030 0 607 47 0 47 47 0 8 0 ffsino 272 2030 0 607 96 0 96 96 0 8 0 nchpl 144 2894 0 1280 61 0 61 61 0 8 0 uvmvnodes 72 2226 0 0 41 0 41 41 0 8 0 vnodes 200 2226 0 0 118 0 118 118 0 8 0 namei 1024 9565 0 9565 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 7325 0 7325 11 9 2 6 0 8 2 sigapl 432 740 0 728 3 1 2 3 0 8 0 futexpl 56 4749 0 4749 2 1 1 1 0 8 1 knotepl 112 361 0 348 1 0 1 1 0 8 0 kqueuepl 104 92 0 90 1 0 1 1 0 8 0 pipepl 112 478 0 465 3 2 1 2 0 8 0 fdescpl 488 741 0 728 4 1 3 3 0 8 1 filepl 152 4137 0 4065 8 3 5 6 0 8 1 lockfpl 104 86 0 86 3 2 1 1 0 8 1 lockfspl 48 31 0 31 3 2 1 1 0 8 1 sessionpl 112 26 0 17 1 0 1 1 0 8 0 pgrppl 48 38 0 29 1 0 1 1 0 8 0 ucredpl 96 1066 0 1058 1 0 1 1 0 8 0 zombiepl 144 728 0 727 2 1 1 1 0 8 0 processpl 888 757 0 727 4 0 4 4 0 8 0 procpl 600 1705 0 1665 4 0 4 4 0 8 0 srpgc 64 60 0 60 2 1 1 1 0 8 1 sockpl 384 621 0 604 4 1 3 3 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 5 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 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 126 0 0 15 0 15 15 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 222 0 0 13 0 13 13 0 8 0 bufpl 256 6138 0 1159 312 0 312 312 0 8 0 anonpl 16 79514 0 74465 39 11 28 38 0 125 1 amapchunkpl 152 5285 0 5202 17 12 5 11 0 158 0 amappl16 192 2774 0 2477 28 9 19 28 0 8 0 amappl15 184 8 0 6 1 0 1 1 0 8 0 amappl14 176 156 0 154 2 1 1 1 0 8 0 amappl13 168 39 0 39 2 1 1 1 0 8 1 amappl12 160 230 0 227 1 0 1 1 0 8 0 amappl11 152 209 0 195 1 0 1 1 0 8 0 amappl10 144 88 0 86 2 1 1 1 0 8 0 amappl9 136 681 0 679 1 0 1 1 0 8 0 amappl8 128 251 0 232 1 0 1 1 0 8 0 amappl7 120 73 0 64 1 0 1 1 0 8 0 amappl6 112 163 0 158 1 0 1 1 0 8 0 amappl5 104 400 0 387 1 0 1 1 0 8 0 amappl4 96 736 0 711 1 0 1 1 0 8 0 amappl3 88 403 0 393 1 0 1 1 0 8 0 amappl2 80 4365 0 4301 4 2 2 3 0 8 0 amappl1 72 27299 0 26879 23 13 10 19 0 8 0 amappl 80 2070 0 2038 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 32 0 8 1 0 1 1 0 8 0 uaddrrnd 24 741 0 727 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 741 0 727 1 0 1 1 0 8 0 vmmpekpl 168 9839 0 9811 2 0 2 2 0 8 0 vmmpepl 168 89069 0 87791 104 37 67 76 0 357 8 vmsppl 360 740 0 727 2 0 2 2 0 8 0 pdppl 4096 1490 0 1454 7 1 6 6 0 8 1 pvpl 32 251390 0 243274 130 38 92 106 0 265 10 pmappl 232 740 0 727 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 469 0 5 14 0 14 14 0 8 0