witness: lock order reversal: 1st 0xffff800020b3b918 &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 __sanitizer_cov_trace_pc+0x50 sys/dev/kcov.c:102 #7 exit1+0x737 sys/kern/kern_exit.c:301 #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(ffff800020b384c8) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800024dff870) 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,ffff800020b384c8,ffff800020b3b980,0,0,2000) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x50 sys/dev/kcov.c:102 exit1(ffff800020b384c8,0,1) at exit1+0x737 sys/kern/kern_exit.c:301 sys_exit(ffff800020b384c8,ffff800024dffa90,ffff800024dffb00) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800024dffb70) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800024dffb70) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffe5124) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe50f0, count: -12 ddb{1}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff800024dff670 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xe864708e3995312f r12 0xfffffd8002661340 r13 0xc r14 0xffffffff823385a0 w_lodata+0x496f0 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800024dff660 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=493456 stat=dead flags process=1018 proc=2000 pri=50, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3b858 user=0xffff800024dfa000, vmspace=0xfffffd807effd708 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 9926 65650 7512 32767 3 0x90 nanosleep syz-executor.1 7512 42185 32552 0 3 0x82 wait syz-executor.1 86800 395488 40833 32767 3 0x90 nanosleep syz-executor.0 40833 137976 32552 0 3 0x82 wait syz-executor.0 96486 237670 0 0 3 0x14200 bored sosplice 32552 17313 52808 0 3 0x82 thrsleep syz-fuzzer 32552 366285 52808 0 3 0x4000082 nanosleep syz-fuzzer 32552 10386 52808 0 3 0x4000082 thrsleep syz-fuzzer 32552 7079 52808 0 3 0x4000082 thrsleep syz-fuzzer 32552 217603 52808 0 3 0x4000082 thrsleep syz-fuzzer 32552 194577 52808 0 3 0x4000082 kqread syz-fuzzer 32552 287805 52808 0 3 0x4000082 thrsleep syz-fuzzer 32552 350590 52808 0 3 0x4000082 thrsleep syz-fuzzer 32552 92879 52808 0 3 0x4000082 thrsleep syz-fuzzer 32552 14995 52808 0 3 0x4000082 thrsleep syz-fuzzer 52808 95535 59715 0 3 0x10008a pause ksh 59715 125092 21289 0 3 0x92 select sshd 28670 365994 1 0 3 0x100083 ttyin getty 21289 286550 1 0 3 0x80 select sshd 40038 99279 14974 73 2 0x100090 syslogd 14974 216658 1 0 3 0x100082 netio syslogd 81331 198814 1 77 3 0x100090 poll dhclient 30002 463800 1 0 3 0x80 poll dhclient 54162 492533 0 0 2 0x14200 zerothread 10026 323435 0 0 3 0x14200 aiodoned aiodoned 30946 208436 0 0 3 0x14200 syncer update 76590 266001 0 0 3 0x14200 cleaner cleaner 47172 302211 0 0 7 0x14200 reaper 58753 404575 0 0 3 0x14200 pgdaemon pagedaemon 26998 358148 0 0 3 0x14200 bored crynlk 76559 308639 0 0 3 0x14200 bored crypto 52899 119063 0 0 3 0x40014200 acpi0 acpi0 59041 493928 0 0 3 0x40014200 idle1 51823 105004 0 0 3 0x14200 bored softnet 68583 521481 0 0 3 0x14200 bored systqmp 56877 46283 0 0 3 0x14200 bored systq 19642 209331 0 0 3 0x40014200 bored softclock 22763 310912 0 0 3 0x40014200 idle0 62748 421411 0 0 3 0x14200 bored smr 1 333938 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 (0xffff800020b3b918) #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 10667 0 0 pcb 23 9K 11K 78643K 604 0 0 rtable 105 3K 3K 78643K 1260 0 0 ifaddr 35 10K 10K 78643K 185 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 65 0 0 iov 0 0K 16K 78643K 78 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1208 76K 76K 78643K 1841 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 15 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 1K 1K 78643K 68 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 6 17K 33K 78643K 1322 0 0 sigio 0 0K 0K 78643K 15 0 0 proc 41 38K 70K 78643K 1394 0 0 subproc 34 2K 2K 78643K 442 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 151 0 0 in_multi 33 2K 2K 78643K 326 0 0 ether_multi 1 0K 0K 78643K 8 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 539 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 21K 78643K 5066 0 0 UVM aobj 50 2K 2K 78643K 58 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 41 0 0 NDP 5 0K 0K 78643K 81 0 0 temp 118 2733K 2799K 78643K 8478 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 54 0 48 1 0 1 1 0 8 0 inpcbpl 280 606 0 599 1 0 1 1 0 8 0 plimitpl 152 113 0 103 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 309 0 265 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 232 0 226 1 0 1 1 0 8 0 nd6 48 78 0 72 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1269 0 1078 12 0 12 12 0 8 0 art_table 32 1270 0 1078 2 0 2 2 0 8 0 art_node 16 308 0 268 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 7 1 0 1 1 0 8 0 semapl 112 66 0 56 1 0 1 1 0 8 0 shmpl 112 56 0 8 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2737 0 1303 47 0 47 47 0 8 0 ffsino 272 2737 0 1303 96 0 96 96 0 8 0 nchpl 144 4401 0 2781 61 0 61 61 0 8 0 uvmvnodes 72 3188 0 0 58 0 58 58 0 8 0 vnodes 200 3188 0 0 168 0 168 168 0 8 0 namei 1024 15370 0 15370 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 11787 0 11787 12 11 1 6 0 8 1 sigapl 432 1421 0 1406 4 2 2 3 0 8 0 futexpl 56 9705 0 9705 1 0 1 1 0 8 1 knotepl 112 759 0 740 1 0 1 1 0 8 0 kqueuepl 104 255 0 253 1 0 1 1 0 8 0 pipepl 112 934 0 915 4 3 1 2 0 8 0 fdescpl 488 1422 0 1407 3 0 3 3 0 8 1 filepl 152 7909 0 7813 7 2 5 6 0 8 1 lockfpl 104 190 0 190 2 1 1 1 0 8 1 lockfspl 48 61 0 61 2 1 1 1 0 8 1 sessionpl 112 41 0 31 1 0 1 1 0 8 0 pgrppl 48 59 0 49 1 0 1 1 0 8 0 ucredpl 96 2146 0 2137 1 0 1 1 0 8 0 zombiepl 144 1407 0 1405 2 1 1 1 0 8 0 processpl 888 1438 0 1405 4 0 4 4 0 8 0 procpl 600 3394 0 3351 4 0 4 4 0 8 0 srpgc 64 144 0 144 4 3 1 1 0 8 1 sosppl 128 17 0 17 4 3 1 1 0 8 1 sockpl 384 1225 0 1208 4 1 3 4 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 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 7 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 104 0 0 12 0 12 12 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 257 0 0 15 0 15 15 0 8 0 bufpl 256 7226 0 1162 379 0 379 379 0 8 0 anonpl 16 135597 0 130352 51 14 37 40 0 125 10 amapchunkpl 152 10300 0 10211 11 6 5 9 0 158 0 amappl16 192 4955 0 4639 37 16 21 28 0 8 5 amappl15 184 74 0 73 1 0 1 1 0 8 0 amappl14 176 359 0 351 2 1 1 1 0 8 0 amappl13 168 155 0 155 3 2 1 1 0 8 1 amappl12 160 119 0 115 1 0 1 1 0 8 0 amappl11 152 236 0 222 1 0 1 1 0 8 0 amappl10 144 170 0 166 2 1 1 1 0 8 0 amappl9 136 1294 0 1291 1 0 1 1 0 8 0 amappl8 128 828 0 807 1 0 1 1 0 8 0 amappl7 120 173 0 165 1 0 1 1 0 8 0 amappl6 112 174 0 167 1 0 1 1 0 8 0 amappl5 104 359 0 347 1 0 1 1 0 8 0 amappl4 96 1389 0 1364 1 0 1 1 0 8 0 amappl3 88 451 0 440 1 0 1 1 0 8 0 amappl2 80 8727 0 8653 4 2 2 3 0 8 0 amappl1 72 45329 0 44887 25 16 9 19 0 8 0 amappl 80 4001 0 3965 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 57 0 8 1 0 1 1 0 8 0 uaddrrnd 24 1422 0 1406 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1422 0 1406 1 0 1 1 0 8 0 vmmpekpl 168 15740 0 15714 2 0 2 2 0 8 0 vmmpepl 168 163116 0 161673 100 32 68 75 0 357 3 vmsppl 360 1421 0 1405 2 0 2 2 0 8 0 pdppl 4096 2852 0 2810 6 0 6 6 0 8 0 pvpl 32 422545 0 414148 145 37 108 111 0 265 30 pmappl 232 1421 0 1405 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 533 0 3 16 0 16 16 0 8 0