login: witness: lock order reversal: 1st 0xffff800020b8cb40 &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 __sanitizer_cov_trace_const_cmp4+0xf sys/dev/kcov.c:197 #7 witness_unlock+0x90 sys/kern/subr_witness.c:1267 #8 mtx_leave+0x97 sys/kern/kern_lock.c:360 #9 sched_exit+0x112 sys/kern/kern_sched.c:225 #10 exit1+0x8bf sys/kern/kern_exit.c:349 #11 sys_exit+0x17 sys/kern/kern_exit.c:94 #12 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #12 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #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(ffff800020b6e270) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800021c41700) 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,ffffffff821fc960,ffff800020ab0ff0) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_const_cmp4(10,ffff800021c417b0) at __sanitizer_cov_trace_const_cmp4+0xf sys/dev/kcov.c:197 witness_unlock(ffff800020b8cb40,8) at witness_unlock+0x90 sys/kern/subr_witness.c:1267 mtx_leave(ffff800020b8cb30) at mtx_leave+0x97 sys/kern/kern_lock.c:360 sched_exit(ffff800020b6e270) at sched_exit+0x112 sys/kern/kern_sched.c:225 exit1(ffff800020b6e270,0,1) at exit1+0x8bf sys/kern/kern_exit.c:349 sys_exit(ffff800020b6e270,ffff800021c419d0,ffff800021c41a40) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800021c41ab0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800021c41ab0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7ffffe8ad4) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8aa0, count: -15 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821fc9e0 __sancov_gen_cov_switch_values.122 rbp 0xffff800021c41500 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff818c8c95 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xd39bbd4ad5e77b2f r12 0xfffffd8002661340 r13 0xc r14 0xffffffff82336c50 w_lodata+0x4ba00 r15 0xffffffff82342280 w_lodata+0x57030 rip 0xffffffff81a42468 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021c414f0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=243265 stat=dead flags process=1008 proc=2000 pri=50, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8ca80 user=0xffff800021c3c000, vmspace=0xfffffd807effd870 estcpu=36, cpticks=11, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 48713 73613 52124 0 4 0x82000 syz-executor.1 48713 255730 52124 0 3 0x4082000 biowait syz-executor.1 48713 282592 52124 0 3 0x4082000 inode syz-executor.1 48713 70378 52124 0 4 0x4082000 syz-executor.1 48713 404515 52124 0 3 0x4002000 suspend syz-executor.1 52124 52340 11331 0 3 0x82 nanosleep syz-executor.1 61467 423144 11331 0 3 0x82 nanosleep syz-executor.0 11331 268260 12713 0 3 0x82 thrsleep syz-fuzzer 11331 446527 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 140262 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 374102 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 381536 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 107727 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 137350 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 394493 12713 0 3 0x4000082 thrsleep syz-fuzzer 11331 321071 12713 0 3 0x4000082 kqread syz-fuzzer 11331 112189 12713 0 3 0x4000082 thrsleep syz-fuzzer 12713 368742 85525 0 3 0x10008a pause ksh 85525 523478 3344 0 3 0x92 select sshd 43240 162635 1 0 3 0x100083 ttyin getty 3344 463049 1 0 3 0x80 select sshd 78025 258661 42053 74 3 0x100092 bpf pflogd 42053 411521 1 0 3 0x80 netio pflogd 57129 395289 43373 73 2 0x100090 syslogd 43373 261406 1 0 3 0x100082 netio syslogd 58867 104649 1 77 3 0x100090 poll dhclient 9596 219751 1 0 3 0x80 poll dhclient 27332 334995 0 0 3 0x14200 pgzero zerothread 59438 243898 0 0 3 0x14200 aiodoned aiodoned 4120 145009 0 0 3 0x14200 syncer update 89708 361318 0 0 3 0x14200 cleaner cleaner 58181 25340 0 0 7 0x14200 reaper 64010 245912 0 0 3 0x14200 pgdaemon pagedaemon 94259 283145 0 0 3 0x14200 bored crynlk 99339 207682 0 0 3 0x14200 bored crypto 36204 502577 0 0 3 0x40014200 acpi0 acpi0 61827 312621 0 0 3 0x40014200 idle1 14072 255566 0 0 3 0x14200 bored softnet 50107 194596 0 0 3 0x14200 bored systqmp 51401 118805 0 0 3 0x14200 bored systq 66324 411032 0 0 3 0x40014200 bored softclock 65191 29611 0 0 3 0x40014200 idle0 73650 509188 0 0 3 0x14200 bored smr 1 74359 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 (0xffff800020b8cb40) #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 Process 48713 (syz-executor.1) thread 0xffff800020b6f080 (255730) exclusive rrwlock inode r = 0 (0xfffffd80679f1b48) #0 witness_lock+0x52e sys/kern/subr_witness.c:1161 #1 rw_enter+0x46d sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:602 #4 vn_write+0x169 vn_lock sys/kern/vfs_vnops.c:549 [inline] #4 vn_write+0x169 sys/kern/vfs_vnops.c:393 #5 dofilewritev+0x1a9 sys/kern/sys_generic.c:364 #6 sys_pwritev+0xb8 sys/kern/vfs_syscalls.c:3254 #7 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #7 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #8 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9475 6399K 6660K 78643K 11070 0 0 pcb 25 9K 10K 78643K 161 0 0 rtable 108 4K 4K 78643K 232 0 0 ifaddr 43 11K 11K 78643K 61 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1475 0 0 iov 1 12K 16K 78643K 21 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1214 76K 77K 78643K 1408 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 5 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 30 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 5 13K 25K 78643K 271 0 0 sigio 0 0K 0K 78643K 12 0 0 proc 53 50K 71K 78643K 399 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 16 0 0 in_multi 33 2K 2K 78643K 41 0 0 ether_multi 1 0K 0K 78643K 2 0 0 mrt 0 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 54 238K 238K 78643K 54 0 0 exec 0 0K 1K 78643K 228 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 101 21K 21K 78643K 1789 0 0 UVM aobj 19 2K 2K 78643K 19 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 12 0 0 NDP 7 0K 0K 78643K 15 0 0 temp 106 2723K 2787K 78643K 4036 0 0 kqueue 0 0K 0K 78643K 1 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 280 145 0 138 1 0 1 1 0 8 0 plimitpl 152 20 0 12 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 48 0 44 1 0 1 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 ppxss 1128 4 0 4 1 0 1 1 0 8 1 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 15 0 3 1 0 1 1 0 8 0 pfstkey 112 15 0 3 1 0 1 1 0 8 0 pfstate 328 15 0 3 2 0 2 2 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 sysvmsgpl 40 10 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 28 0 18 1 0 1 1 0 8 0 shmpl 112 17 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1814 0 391 48 1 47 47 0 8 1 ffsino 272 1814 0 391 96 0 96 96 0 8 0 nchpl 144 2388 0 745 61 0 61 61 0 8 0 uvmvnodes 72 1988 0 0 37 0 37 37 0 8 0 vnodes 200 1988 0 0 105 0 105 105 0 8 0 namei 1024 6545 0 6545 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 6270 0 6269 6 5 1 5 0 8 0 sigapl 432 471 0 456 3 1 2 3 0 8 0 futexpl 56 2746 0 2746 1 0 1 1 0 8 1 knotepl 112 98 0 79 1 0 1 1 0 8 0 kqueuepl 104 53 0 51 1 0 1 1 0 8 0 pipepl 112 276 0 255 2 1 1 1 0 8 0 fdescpl 488 472 0 456 4 1 3 3 0 8 1 filepl 152 2363 0 2259 5 0 5 5 0 8 1 lockfpl 104 66 0 65 2 1 1 1 0 8 0 lockfspl 48 25 0 24 2 1 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 20 0 9 1 0 1 1 0 8 0 ucredpl 96 265 0 256 1 0 1 1 0 8 0 zombiepl 144 456 0 455 3 2 1 1 0 8 0 processpl 888 487 0 455 4 0 4 4 0 8 0 procpl 600 1033 0 987 4 0 4 4 0 8 0 sockpl 384 275 0 256 4 1 3 3 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 125 0 0 15 0 15 15 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 154 0 0 9 0 9 9 0 8 0 bufpl 256 6152 0 1188 311 0 311 311 0 8 0 anonpl 16 48336 0 37935 44 2 42 42 0 125 0 amapchunkpl 152 2351 0 2243 7 2 5 7 0 158 0 amappl16 192 1599 0 1042 28 0 28 28 0 8 0 amappl15 184 115 0 113 1 0 1 1 0 8 0 amappl14 176 160 0 153 2 1 1 1 0 8 0 amappl12 160 8 0 7 1 0 1 1 0 8 0 amappl11 152 57 0 38 1 0 1 1 0 8 0 amappl10 144 73 0 69 1 0 1 1 0 8 0 amappl9 136 717 0 712 1 0 1 1 0 8 0 amappl8 128 258 0 243 1 0 1 1 0 8 0 amappl7 120 34 0 30 1 0 1 1 0 8 0 amappl6 112 58 0 51 1 0 1 1 0 8 0 amappl5 104 120 0 106 1 0 1 1 0 8 0 amappl4 96 526 0 502 1 0 1 1 0 8 0 amappl3 88 422 0 408 1 0 1 1 0 8 0 amappl2 80 2904 0 2824 4 2 2 3 0 8 0 amappl1 72 19679 0 19209 25 15 10 20 0 8 0 amappl 80 1284 0 1241 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 18 0 0 1 0 1 1 0 8 0 uaddrrnd 24 472 0 455 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 472 0 455 1 0 1 1 0 8 0 vmmpekpl 168 7501 0 7466 2 0 2 2 0 8 0 vmmpepl 168 58270 0 56549 92 17 75 81 0 357 0 vmsppl 360 471 0 455 2 0 2 2 0 8 0 pdppl 4096 952 0 910 7 1 6 6 0 8 0 pvpl 32 173007 0 159306 120 5 115 115 0 265 4 pmappl 232 471 0 455 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 463 0 4 14 0 14 14 0 8 0