witness: lock order reversal: 1st 0xffff800020b8c7c8 &pr->ps_mtx (&pr->ps_mtx) 2nd 0xffffffff82384c80 &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 splraise+0x3d sys/arch/amd64/amd64/intr.c:692 #7 witness_unlock+0x10c sys/kern/subr_witness.c:1272 #8 mtx_leave+0x97 sys/kern/kern_lock.c:360 #9 exit1+0x6e5 sys/kern/kern_exit.c:292 #10 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #11 userret+0x347 sys/kern/kern_sig.c:1907 #12 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #12 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #13 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(ffffffff82384c80,9,0) at witness_checkorder+0xffc witness_debugger sys/kern/subr_witness.c:2504 [inline] witness_checkorder(ffffffff82384c80,9,0) at witness_checkorder+0xffc sys/kern/subr_witness.c:1084 __mp_lock(ffffffff82384a78) at __mp_lock+0xa1 schedclock(ffff800020b38270) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800021c41b00) 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,ffffffff817951cd,0,0,9,d) at Xresume_lapic_ltimer+0x26 splraise(d) at splraise+0x3d sys/arch/amd64/amd64/intr.c:692 witness_unlock(ffff800020b8c7c8,8) at witness_unlock+0x10c sys/kern/subr_witness.c:1272 mtx_leave(ffff800020b8c7b8) at mtx_leave+0x97 sys/kern/kern_lock.c:360 exit1(ffff800020b38270,0,3) at exit1+0x6e5 sys/kern/kern_exit.c:292 single_thread_check(ffff800020b38270,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b38270) at userret+0x347 sys/kern/kern_sig.c:1907 syscall(ffff800021c41ef0) at syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(ffff800021c41ef0) at syscall+0x614 sys/arch/amd64/amd64/trap.c:596 Xsyscall(6,4,d14981e68e0,53,0,d142eb04a00) at Xsyscall+0x128 end of kernel end trace frame: 0xd14b9c0c780, count: -15 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821fc9e0 __sancov_gen_cov_switch_values.122 rbp 0xffff800021c41900 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff818c8c95 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xfba2aa495a1c0668 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff82338720 w_lodata+0x4d4d0 r15 0xffffffff82342280 w_lodata+0x57030 rip 0xffffffff81a42468 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021c418f0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=455521 stat=dead flags process=1000 proc=4082000 pri=50, usrpri=56, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8c708 user=0xffff800021c3c000, vmspace=0xfffffd807effd9d8 estcpu=6, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 52705 11144 31390 0 3 0x80 nanosleep syz-executor.1 52705 423644 31390 0 2 0x4000000 syz-executor.1 52705 123446 31390 0 2 0x4000000 syz-executor.1 52705 61220 31390 0 3 0x4000080 fsleep syz-executor.1 57165 355636 63229 0 7 0x3000 syz-executor.0 9731 357723 0 0 3 0x14200 bored sosplice 31390 469218 95726 0 3 0x82 nanosleep syz-executor.1 63229 345722 95726 0 3 0x82 nanosleep syz-executor.0 95726 46253 3398 0 3 0x82 thrsleep syz-fuzzer 95726 293099 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 287086 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 386613 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 71550 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 174154 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 387099 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 63802 3398 0 3 0x4000082 kqread syz-fuzzer 95726 196926 3398 0 3 0x4000082 thrsleep syz-fuzzer 95726 127534 3398 0 3 0x4000082 thrsleep syz-fuzzer 3398 280592 56142 0 3 0x10008a pause ksh 56142 149940 30596 0 3 0x92 select sshd 1129 237844 1 0 3 0x100083 ttyin getty 30596 69326 1 0 3 0x80 select sshd 84117 300255 54890 74 3 0x100092 bpf pflogd 54890 58556 1 0 3 0x80 netio pflogd 7670 474959 41995 73 2 0x100090 syslogd 41995 517948 1 0 3 0x100082 netio syslogd 2567 455908 1 77 3 0x100090 poll dhclient 6709 95537 1 0 3 0x80 poll dhclient 78071 201997 0 0 2 0x14200 zerothread 44555 223007 0 0 3 0x14200 aiodoned aiodoned 36569 486579 0 0 3 0x14200 syncer update 18532 131053 0 0 3 0x14200 cleaner cleaner 48689 230253 0 0 3 0x14200 reaper reaper 56592 486139 0 0 3 0x14200 pgdaemon pagedaemon 85383 335593 0 0 3 0x14200 bored crynlk 47199 489324 0 0 3 0x14200 bored crypto 28781 368778 0 0 3 0x40014200 acpi0 acpi0 48907 23033 0 0 3 0x40014200 idle1 48969 9958 0 0 3 0x14200 bored softnet 75678 171931 0 0 3 0x14200 bored systqmp 72885 107920 0 0 3 0x14200 bored systq 4262 451890 0 0 3 0x40014200 bored softclock 61870 79813 0 0 3 0x40014200 idle0 10737 225445 0 0 3 0x14200 bored smr 1 359009 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 (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 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #6 userret+0x347 sys/kern/kern_sig.c:1907 #7 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #7 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #8 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9475 6391K 6780K 78643K 10707 0 0 pcb 29 10K 10K 78643K 73 0 0 rtable 105 3K 3K 78643K 203 0 0 ifaddr 42 10K 10K 78643K 43 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1469 0 0 iov 0 0K 12K 78643K 4 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1210 76K 76K 78643K 1279 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 4 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 6 0K 0K 78643K 6 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 6 17K 25K 78643K 90 0 0 proc 53 50K 83K 78643K 370 0 0 subproc 32 2K 2K 78643K 34 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 8 0 0 in_multi 33 2K 2K 78643K 33 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 48 212K 212K 78643K 48 0 0 exec 0 0K 1K 78643K 209 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 90 29K 29K 78643K 1184 0 0 UVM aobj 4 2K 2K 78643K 4 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 1 0 0 NDP 7 0K 0K 78643K 11 0 0 temp 97 2720K 2792K 78643K 3491 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 6 0 0 1 0 1 1 0 8 0 inpcbpl 280 67 0 60 1 0 1 1 0 8 0 plimitpl 152 18 0 10 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 22 0 18 1 0 1 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 12 0 2 1 0 1 1 0 8 0 pfstkey 112 12 0 2 1 0 1 1 0 8 0 pfstate 328 12 0 2 1 0 1 1 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 189 0 0 12 0 12 12 0 8 0 art_table 32 190 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 semapl 112 4 0 0 1 0 1 1 0 8 0 shmpl 112 2 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1533 0 112 47 0 47 47 0 8 0 ffsino 272 1533 0 112 96 0 96 96 0 8 0 nchpl 144 1832 0 190 61 0 61 61 0 8 0 uvmvnodes 72 1626 0 0 30 0 30 30 0 8 0 vnodes 200 1626 0 0 86 0 86 86 0 8 0 namei 1024 4779 0 4779 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 1 0 1 1 0 1 1 0 8 1 scxspl 192 4602 0 4602 8 7 1 6 0 8 1 sigapl 432 290 0 274 3 0 3 3 0 8 1 futexpl 56 812 0 811 1 0 1 1 0 8 0 knotepl 112 71 0 52 1 0 1 1 0 8 0 kqueuepl 104 19 0 15 1 0 1 1 0 8 0 pipepl 112 172 0 151 2 1 1 1 0 8 0 fdescpl 488 291 0 274 3 0 3 3 0 8 0 filepl 152 1424 0 1315 5 0 5 5 0 8 0 lockfpl 104 20 0 20 2 1 1 1 0 8 1 lockfspl 48 8 0 8 2 1 1 1 0 8 1 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 22 0 11 1 0 1 1 0 8 0 ucredpl 96 105 0 96 1 0 1 1 0 8 0 zombiepl 144 275 0 274 2 1 1 1 0 8 0 processpl 888 307 0 274 4 0 4 4 0 8 0 procpl 600 434 0 388 4 0 4 4 0 8 0 sosppl 128 2 0 2 1 0 1 1 0 8 1 sockpl 384 123 0 100 3 0 3 3 0 8 0 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 131 0 0 16 0 16 16 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 165 0 0 10 0 10 10 0 8 0 bufpl 256 5795 0 1188 288 0 288 288 0 8 0 anonpl 16 37571 0 26053 49 2 47 47 0 125 0 amapchunkpl 152 1422 0 1199 9 0 9 9 0 158 0 amappl16 192 826 0 324 26 0 26 26 0 8 0 amappl15 184 31 0 29 1 0 1 1 0 8 0 amappl14 176 70 0 65 2 1 1 1 0 8 0 amappl12 160 41 0 37 1 0 1 1 0 8 0 amappl11 152 59 0 41 1 0 1 1 0 8 0 amappl10 144 74 0 72 1 0 1 1 0 8 0 amappl9 136 592 0 588 1 0 1 1 0 8 0 amappl8 128 154 0 138 1 0 1 1 0 8 0 amappl7 120 33 0 30 1 0 1 1 0 8 0 amappl6 112 56 0 50 1 0 1 1 0 8 0 amappl5 104 148 0 132 1 0 1 1 0 8 0 amappl4 96 437 0 412 1 0 1 1 0 8 0 amappl3 88 206 0 194 1 0 1 1 0 8 0 amappl2 80 1466 0 1383 3 1 2 3 0 8 0 amappl1 72 16093 0 15607 25 10 15 20 0 8 5 amappl 80 689 0 649 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 3 0 0 1 0 1 1 0 8 0 uaddrrnd 24 291 0 274 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 291 0 274 1 0 1 1 0 8 0 vmmpekpl 168 6318 0 6286 2 0 2 2 0 8 0 vmmpepl 168 39732 0 38053 97 12 85 85 0 357 12 vmsppl 360 290 0 274 2 0 2 2 0 8 0 pdppl 4096 590 0 548 6 0 6 6 0 8 0 pvpl 32 136372 0 121609 120 0 120 120 0 265 0 pmappl 232 290 0 274 2 0 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 443 0 4 13 0 13 13 0 8 0