witness: lock order reversal: 1st 0xffff800020b3b228 &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 #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(ffff800020b38978) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800022df2fb0) 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,ffff800020b3b218,0,ffff800020b3b168,2000) at Xresume_lapic_ltimer+0x26 calcru(ffff800020b38978,0,1,ffff800020b38978) at calcru sys_exit(ffff800020b38978,ffff800022df3130,ffff800022df31a0) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800022df3210) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800022df3210) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffc2974) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc2940, count: -11 ddb{1}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff800022df2db0 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xf3a9a9c56ab2a5ab r12 0xfffffd8002661340 r13 0xc r14 0xffffffff823359a0 w_lodata+0x46af0 r15 0xffffffff82346040 w_lodata+0x57190 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022df2da0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=423666 stat=dead flags process=1018 proc=2000 pri=50, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3b168 user=0xffff800022dee000, vmspace=0xfffffd807effd9d8 estcpu=31, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 91421 154597 4282 32767 3 0x90 piperd syz-executor.1 4282 72504 99507 0 3 0x82 wait syz-executor.1 17090 122479 55632 32767 3 0x90 nanosleep syz-executor.0 55632 150819 99507 0 3 0x82 wait syz-executor.0 47268 77472 0 0 3 0x14200 bored sosplice 99507 390630 16881 0 3 0x82 thrsleep syz-fuzzer 99507 443923 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 351249 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 283405 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 145527 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 427653 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 381600 16881 0 3 0x4000082 kqread syz-fuzzer 99507 209582 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 46364 16881 0 3 0x4000082 thrsleep syz-fuzzer 99507 137484 16881 0 3 0x4000082 thrsleep syz-fuzzer 16881 372546 79105 0 3 0x10008a pause ksh 79105 454411 34041 0 3 0x92 select sshd 10688 403155 1 0 3 0x100083 ttyin getty 34041 322104 1 0 3 0x80 select sshd 55168 210906 19273 73 2 0x100090 syslogd 19273 299515 1 0 3 0x100082 netio syslogd 59558 311701 1 77 3 0x100090 poll dhclient 17407 177043 1 0 3 0x80 poll dhclient 98768 107948 0 0 3 0x14200 pgzero zerothread 55033 1151 0 0 3 0x14200 aiodoned aiodoned 67494 373134 0 0 3 0x14200 syncer update 51415 221471 0 0 3 0x14200 cleaner cleaner 62962 522638 0 0 7 0x14200 reaper 27369 158168 0 0 3 0x14200 pgdaemon pagedaemon 15561 17955 0 0 3 0x14200 bored crynlk 71120 40506 0 0 3 0x14200 bored crypto 39724 368507 0 0 3 0x40014200 acpi0 acpi0 71163 243333 0 0 3 0x40014200 idle1 31815 72630 0 0 3 0x14200 bored softnet 1675 520235 0 0 3 0x14200 bored systqmp 5014 17401 0 0 3 0x14200 bored systq 57867 252367 0 0 3 0x40014200 bored softclock 46268 98774 0 0 3 0x40014200 idle0 52549 131408 0 0 3 0x14200 bored smr 1 271476 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 (0xffff800020b3b228) #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 10721 0 0 pcb 23 9K 11K 78643K 1061 0 0 rtable 105 3K 3K 78643K 1763 0 0 ifaddr 36 11K 11K 78643K 251 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 70 0 0 iov 0 0K 16K 78643K 143 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 2264 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 25 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 157 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 6 17K 33K 78643K 2282 0 0 sigio 0 0K 0K 78643K 23 0 0 proc 41 38K 70K 78643K 1885 0 0 subproc 34 2K 2K 78643K 629 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 251 0 0 in_multi 33 2K 2K 78643K 492 0 0 ether_multi 1 0K 0K 78643K 17 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 726 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 8452 0 0 UVM aobj 91 6K 6K 78643K 105 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 133 0 0 NDP 5 0K 0K 78643K 114 0 0 temp 121 2734K 2810K 78643K 11874 0 0 kqueue 0 0K 0K 78643K 24 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 76 0 70 1 0 1 1 0 8 0 inpcbpl 280 1111 0 1104 1 0 1 1 0 8 0 plimitpl 152 188 0 179 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 430 0 386 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 386 0 382 1 0 1 1 0 8 0 ipq 40 1 0 1 1 1 0 1 0 8 0 ipqe 40 2 0 2 1 1 0 1 0 8 0 nd6 48 111 0 105 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1748 0 1557 13 1 12 13 0 8 0 art_table 32 1749 0 1557 2 0 2 2 0 8 0 art_node 16 429 0 389 1 0 1 1 0 8 0 sysvmsgpl 40 21 0 9 1 0 1 1 0 8 0 semapl 112 155 0 145 1 0 1 1 0 8 0 shmpl 112 103 0 14 4 1 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3880 0 2439 47 0 47 47 0 8 0 ffsino 272 3880 0 2439 97 0 97 97 0 8 0 nchpl 144 6633 0 5014 61 0 61 61 0 8 0 uvmvnodes 72 4518 0 0 83 0 83 83 0 8 0 vnodes 200 4518 0 0 238 0 238 238 0 8 0 namei 1024 24000 0 24000 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 17305 0 17305 16 15 1 6 0 8 1 sigapl 432 2348 0 2333 3 1 2 3 0 8 0 futexpl 56 18565 0 18565 1 0 1 1 0 8 1 knotepl 112 1215 0 1196 1 0 1 1 0 8 0 kqueuepl 104 519 0 517 1 0 1 1 0 8 0 pipepl 112 1484 0 1465 7 6 1 2 0 8 0 fdescpl 488 2349 0 2334 3 0 3 3 0 8 1 filepl 152 13804 0 13708 11 6 5 7 0 8 1 lockfpl 104 389 0 389 5 4 1 1 0 8 1 lockfspl 48 125 0 125 5 4 1 1 0 8 1 sessionpl 112 52 0 42 1 0 1 1 0 8 0 pgrppl 48 80 0 70 1 0 1 1 0 8 0 ucredpl 96 4282 0 4273 1 0 1 1 0 8 0 zombiepl 144 2334 0 2333 2 1 1 1 0 8 0 processpl 888 2365 0 2333 4 0 4 4 0 8 0 procpl 600 6297 0 6255 5 1 4 5 0 8 0 srpgc 64 210 0 210 8 8 0 1 0 8 0 sosppl 128 35 0 35 9 9 0 1 0 8 0 sockpl 384 2195 0 2178 6 3 3 4 0 8 1 mcl64k 65536 6 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 13 0 0 1 0 1 1 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 15 0 0 2 0 2 2 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 129 0 0 16 0 16 16 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 270 0 0 13 0 13 13 0 8 0 bufpl 256 8295 0 1290 438 0 438 438 0 8 0 anonpl 16 253821 0 247729 92 51 41 41 0 125 12 amapchunkpl 152 18098 0 18008 40 35 5 9 0 158 0 amappl16 192 10235 0 9922 83 55 28 28 0 8 11 amappl15 184 532 0 531 1 0 1 1 0 8 0 amappl14 176 737 0 734 2 1 1 1 0 8 0 amappl13 168 188 0 188 4 3 1 1 0 8 1 amappl12 160 515 0 510 1 0 1 1 0 8 0 amappl11 152 202 0 188 1 0 1 1 0 8 0 amappl10 144 365 0 361 2 1 1 1 0 8 0 amappl9 136 1038 0 1035 1 0 1 1 0 8 0 amappl8 128 573 0 550 1 0 1 1 0 8 0 amappl7 120 350 0 342 1 0 1 1 0 8 0 amappl6 112 125 0 114 1 0 1 1 0 8 0 amappl5 104 795 0 784 1 0 1 1 0 8 0 amappl4 96 2213 0 2190 1 0 1 1 0 8 0 amappl3 88 905 0 894 1 0 1 1 0 8 0 amappl2 80 15500 0 15433 4 2 2 3 0 8 0 amappl1 72 71087 0 70635 26 17 9 19 0 8 0 amappl 80 7066 0 7029 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 64 104 0 14 2 0 2 2 0 8 0 uaddrrnd 24 2349 0 2333 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2349 0 2333 1 0 1 1 0 8 0 vmmpekpl 168 23854 0 23826 2 0 2 2 0 8 0 vmmpepl 168 268293 0 266879 140 64 76 83 0 357 11 vmsppl 360 2348 0 2333 2 0 2 2 0 8 0 pdppl 4096 4706 0 4666 6 0 6 6 0 8 0 pvpl 32 705109 0 695804 199 91 108 112 0 265 27 pmappl 232 2348 0 2333 5 4 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 598 0 4 17 0 17 17 0 8 0