login: 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 __sanitizer_cov_trace_cmp4+0x2c inintr sys/dev/kcov.c:438 [inline] #6 __sanitizer_cov_trace_cmp4+0x2c trace_cmp sys/dev/kcov.c:136 [inline] #6 __sanitizer_cov_trace_cmp4+0x2c sys/dev/kcov.c:170 #7 splraise+0x3d sys/arch/amd64/amd64/intr.c:692 #8 witness_unlock+0x10c sys/kern/subr_witness.c:1272 #9 mtx_leave+0x97 sys/kern/kern_lock.c:360 #10 sched_exit+0x112 sys/kern/kern_sched.c:225 #11 exit1+0x8bf sys/kern/kern_exit.c:349 #12 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #13 userret+0x347 sys/kern/kern_sig.c:1907 #14 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #14 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #15 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(ffff800020b38720) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff80002503d6a0) 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,ffffffff81bfe4ad,0,0,9,d) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_cmp4(9,d) at __sanitizer_cov_trace_cmp4+0x2c inintr sys/dev/kcov.c:438 [inline] __sanitizer_cov_trace_cmp4(9,d) at __sanitizer_cov_trace_cmp4+0x2c trace_cmp sys/dev/kcov.c:136 [inline] __sanitizer_cov_trace_cmp4(9,d) at __sanitizer_cov_trace_cmp4+0x2c sys/dev/kcov.c:170 splraise(d) at splraise+0x3d sys/arch/amd64/amd64/intr.c:692 witness_unlock(ffff800020b3b228,8) at witness_unlock+0x10c sys/kern/subr_witness.c:1272 mtx_leave(ffff800020b3b218) at mtx_leave+0x97 sys/kern/kern_lock.c:360 sched_exit(ffff800020b38720) at sched_exit+0x112 sys/kern/kern_sched.c:225 exit1(ffff800020b38720,0,3) at exit1+0x8bf sys/kern/kern_exit.c:349 single_thread_check(ffff800020b38720,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b38720) at userret+0x347 sys/kern/kern_sig.c:1907 syscall(ffff80002503db30) at syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(ffff80002503db30) at syscall+0x614 sys/arch/amd64/amd64/trap.c:596 Xsyscall(6,4,f2a69dd8d20,53,0,f2a2ea2d400) at Xsyscall+0x128 end of kernel end trace frame: 0xf2a91a13530, count: -17 ddb{1}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff80002503d4a0 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xeafe962bdc0c609b r12 0xfffffd8002661340 r13 0xc r14 0xffffffff8233acd0 w_lodata+0x4be20 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002503d490 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=36016 stat=dead flags process=1010 proc=4082000 pri=50, usrpri=76, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3b168 user=0xffff800025038000, vmspace=0xfffffd807effd000 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 79815 66290 76067 32767 3 0x3010 suspend syz-executor.1 79815 246820 76067 32767 7 0x4081010 syz-executor.1 76067 222986 81270 32767 3 0x90 nanosleep syz-executor.1 81270 470870 25122 0 3 0x82 wait syz-executor.1 34113 323904 45960 32767 3 0x90 nanosleep syz-executor.0 45960 24567 25122 0 3 0x82 wait syz-executor.0 33640 523312 0 0 3 0x14200 bored sosplice 25122 510245 32577 0 3 0x82 kqread syz-fuzzer 25122 435021 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 165408 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 389375 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 117718 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 19190 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 76068 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 136027 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 309534 32577 0 3 0x4000082 thrsleep syz-fuzzer 25122 123105 32577 0 3 0x4000082 thrsleep syz-fuzzer 32577 368835 86917 0 3 0x10008a pause ksh 86917 407312 57848 0 3 0x92 select sshd 75478 337446 1 0 3 0x100083 ttyin getty 57848 499915 1 0 3 0x80 select sshd 11815 158856 58616 73 2 0x100090 syslogd 58616 360591 1 0 3 0x100082 netio syslogd 21534 121586 1 77 3 0x100090 poll dhclient 47521 3919 1 0 3 0x80 poll dhclient 27821 367118 0 0 3 0x14200 pgzero zerothread 40595 86873 0 0 3 0x14200 aiodoned aiodoned 57758 126071 0 0 3 0x14200 syncer update 56491 30092 0 0 3 0x14200 cleaner cleaner 40680 469919 0 0 3 0x14200 reaper reaper 4901 250020 0 0 3 0x14200 pgdaemon pagedaemon 36294 61762 0 0 3 0x14200 bored crynlk 74473 401208 0 0 3 0x14200 bored crypto 61528 271947 0 0 3 0x40014200 acpi0 acpi0 57767 53670 0 0 3 0x40014200 idle1 35766 76884 0 0 3 0x14200 bored softnet 98487 40992 0 0 3 0x14200 bored systqmp 43337 238273 0 0 3 0x14200 bored systq 94159 316310 0 0 3 0x40014200 bored softclock 90910 262456 0 0 3 0x40014200 idle0 73742 362069 0 0 3 0x14200 bored smr 1 335765 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 sched_exit+0xa5 sys/kern/kern_sched.c:224 #4 exit1+0x8bf sys/kern/kern_exit.c:349 #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 9459 6321K 6321K 78643K 10601 0 0 pcb 23 9K 11K 78643K 277 0 0 rtable 105 3K 3K 78643K 677 0 0 ifaddr 35 10K 10K 78643K 104 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 36 0 0 iov 0 0K 16K 78643K 26 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 1491 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 1K 78643K 53 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 7 21K 33K 78643K 596 0 0 sigio 0 0K 0K 78643K 4 0 0 proc 41 38K 70K 78643K 812 0 0 subproc 34 2K 2K 78643K 221 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 62 0 0 in_multi 33 2K 2K 78643K 169 0 0 ether_multi 1 0K 0K 78643K 4 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 346 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 91 21K 21K 78643K 2761 0 0 UVM aobj 28 2K 2K 78643K 29 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 42 0 0 temp 100 2728K 2795K 78643K 5478 0 0 kqueue 0 0K 0K 78643K 2 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 28 0 22 1 0 1 1 0 8 0 inpcbpl 280 324 0 317 1 0 1 1 0 8 0 plimitpl 152 54 0 45 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 166 0 122 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 108 0 104 1 0 1 1 0 8 0 nd6 48 39 0 33 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 679 0 488 12 0 12 12 0 8 0 art_table 32 680 0 488 2 0 2 2 0 8 0 art_node 16 165 0 125 1 0 1 1 0 8 0 sysvmsgpl 40 10 0 6 1 0 1 1 0 8 0 semapl 112 51 0 41 1 0 1 1 0 8 0 shmpl 112 27 0 1 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1982 0 555 47 0 47 47 0 8 0 ffsino 272 1982 0 555 96 0 96 96 0 8 0 nchpl 144 2815 0 1196 61 0 61 61 0 8 0 uvmvnodes 72 2212 0 0 41 0 41 41 0 8 0 vnodes 200 2212 0 0 117 0 117 117 0 8 0 namei 1024 8816 0 8816 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 7008 0 7008 9 8 1 6 0 8 1 sigapl 432 734 0 719 3 1 2 3 0 8 0 futexpl 56 4191 0 4191 1 0 1 1 0 8 1 knotepl 112 376 0 357 1 0 1 1 0 8 0 kqueuepl 104 113 0 111 1 0 1 1 0 8 0 pipepl 112 460 0 441 3 1 2 2 0 8 1 fdescpl 488 735 0 719 3 0 3 3 0 8 0 filepl 152 3897 0 3797 8 1 7 7 0 8 3 lockfpl 104 106 0 104 3 2 1 1 0 8 0 lockfspl 48 35 0 34 3 2 1 1 0 8 0 sessionpl 112 28 0 18 1 0 1 1 0 8 0 pgrppl 48 30 0 20 1 0 1 1 0 8 0 ucredpl 96 895 0 886 1 0 1 1 0 8 0 zombiepl 144 720 0 718 2 1 1 1 0 8 0 processpl 888 751 0 718 4 0 4 4 0 8 0 procpl 600 1635 0 1591 4 0 4 4 0 8 0 srpgc 64 66 0 66 2 1 1 1 0 8 1 sosppl 128 13 0 13 1 0 1 1 0 8 1 sockpl 384 601 0 584 4 0 4 4 0 8 2 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 5 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 113 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 181 0 0 11 0 11 11 0 8 0 bufpl 256 6079 0 1159 308 0 308 308 0 8 0 anonpl 16 73219 0 67934 41 16 25 40 0 125 0 amapchunkpl 152 4673 0 4579 6 0 6 6 0 158 0 amappl16 192 2526 0 2238 32 16 16 27 0 8 1 amappl15 184 32 0 31 2 1 1 1 0 8 0 amappl14 176 120 0 117 2 1 1 1 0 8 0 amappl13 168 265 0 265 1 0 1 1 0 8 1 amappl12 160 69 0 65 1 0 1 1 0 8 0 amappl11 152 140 0 126 1 0 1 1 0 8 0 amappl10 144 99 0 97 2 1 1 1 0 8 0 amappl9 136 745 0 741 1 0 1 1 0 8 0 amappl8 128 265 0 249 1 0 1 1 0 8 0 amappl7 120 82 0 71 1 0 1 1 0 8 0 amappl6 112 104 0 97 1 0 1 1 0 8 0 amappl5 104 236 0 223 1 0 1 1 0 8 0 amappl4 96 814 0 792 1 0 1 1 0 8 0 amappl3 88 225 0 214 1 0 1 1 0 8 0 amappl2 80 4220 0 4154 4 2 2 3 0 8 0 amappl1 72 28020 0 27570 23 13 10 19 0 8 0 amappl 80 2035 0 1997 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 28 0 1 1 0 1 1 0 8 0 uaddrrnd 24 735 0 719 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 735 0 719 1 0 1 1 0 8 0 vmmpekpl 168 9666 0 9639 2 0 2 2 0 8 0 vmmpepl 168 88255 0 86875 99 31 68 75 0 357 7 vmsppl 360 734 0 719 2 0 2 2 0 8 0 pdppl 4096 1478 0 1438 6 0 6 6 0 8 0 pvpl 32 242533 0 234051 115 24 91 112 0 265 15 pmappl 232 734 0 719 3 1 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 460 0 3 14 0 14 14 0 8 0