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 __sanitizer_cov_trace_pc #7 mtx_leave+0x97 sys/kern/kern_lock.c:360 #8 sched_exit+0x112 sys/kern/kern_sched.c:225 #9 exit1+0x8bf sys/kern/kern_exit.c:349 #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(ffff800020b39080) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800022c65360) 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,ffffffff8123ad46,ffff800020ab0ff0,0,0,ffff800020b8c7b8) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc mtx_leave(ffff800020b8c7b8) at mtx_leave+0x97 sys/kern/kern_lock.c:360 sched_exit(ffff800020b39080) at sched_exit+0x112 sys/kern/kern_sched.c:225 exit1(ffff800020b39080,0,3) at exit1+0x8bf sys/kern/kern_exit.c:349 single_thread_check(ffff800020b39080,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b39080) at userret+0x347 sys/kern/kern_sig.c:1907 syscall(ffff800022c65790) at syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(ffff800022c65790) at syscall+0x614 sys/arch/amd64/amd64/trap.c:596 Xsyscall(6,4,7c52edf1fe0,53,0,7c564e70c00) at Xsyscall+0x128 end of kernel end trace frame: 0x7c4e4200d20, count: -15 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821fc9e0 __sancov_gen_cov_switch_values.122 rbp 0xffff800022c65160 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff818c8c95 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x5d44ec06d4823321 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff8232fc40 w_lodata+0x449f0 r15 0xffffffff82342280 w_lodata+0x57030 rip 0xffffffff81a42468 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022c65150 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=184178 stat=dead flags process=1000 proc=4082000 pri=50, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8c708 user=0xffff800022c60000, vmspace=0xfffffd807effd2d0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 32332 350854 78540 0 2 0x3000 syz-executor.1 82429 169541 1 0 3 0x100083 ttyin getty 90932 53635 66189 0 3 0x82 nanosleep syz-executor.0 61281 136683 0 0 3 0x14200 bored sosplice 78540 190469 66189 0 3 0x82 nanosleep syz-executor.1 66189 480622 70020 0 3 0x82 thrsleep syz-fuzzer 66189 288434 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 348826 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 217101 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 374671 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 460938 70020 0 3 0x4000082 kqread syz-fuzzer 66189 381238 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 345862 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 130322 70020 0 3 0x4000082 thrsleep syz-fuzzer 66189 244971 70020 0 3 0x4000082 thrsleep syz-fuzzer 70020 415508 43456 0 3 0x10008a pause ksh 43456 121338 85956 0 3 0x92 select sshd 85956 302462 1 0 3 0x80 select sshd 1485 290250 29405 74 3 0x100092 bpf pflogd 29405 175051 1 0 3 0x80 netio pflogd 63227 281049 24326 73 7 0x100090 syslogd 24326 415951 1 0 3 0x100082 netio syslogd 17143 473783 0 0 3 0x14200 pgzero zerothread 30072 288839 0 0 3 0x14200 aiodoned aiodoned 29933 323271 0 0 3 0x14200 syncer update 17134 168328 0 0 3 0x14200 cleaner cleaner 41984 486470 0 0 2 0x14200 reaper 39626 131317 0 0 3 0x14200 pgdaemon pagedaemon 99911 461239 0 0 3 0x14200 bored crynlk 56157 5148 0 0 3 0x14200 bored crypto 3134 5718 0 0 3 0x40014200 acpi0 acpi0 79248 38502 0 0 3 0x40014200 idle1 17069 480907 0 0 3 0x14200 bored softnet 2901 126130 0 0 3 0x14200 bored systqmp 36167 416061 0 0 3 0x14200 bored systq 48555 21388 0 0 3 0x40014200 bored softclock 22581 7596 0 0 3 0x40014200 idle0 65208 351199 0 0 3 0x14200 bored smr 1 349088 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 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 9529 6374K 6924K 78643K 16045 0 0 pcb 21 9K 10K 78643K 1117 0 0 rtable 112 4K 5K 78643K 343 0 0 ifaddr 64 15K 16K 78643K 291 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1556 0 0 iov 0 0K 28K 78643K 293 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1202 75K 76K 78643K 3390 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 34 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 207 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 5 13K 25K 78643K 2533 0 0 sigio 0 0K 0K 78643K 57 0 0 proc 54 51K 83K 78643K 704 0 0 subproc 32 2K 2K 78643K 51 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 144 0 0 in_multi 33 2K 2K 78643K 109 0 0 ether_multi 1 0K 0K 78643K 7 0 0 mrt 0 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 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 382 0 0 pfkey data 0 0K 0K 78643K 2 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 88 20K 29K 78643K 9268 0 0 UVM aobj 100 3K 3K 78643K 110 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 140 0 0 NDP 13 0K 0K 78643K 76 0 0 temp 180 2735K 2805K 78643K 10894 0 0 kqueue 0 0K 0K 78643K 18 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 8 0 2 1 0 1 1 0 8 0 inpcbpl 280 1034 0 1030 1 0 1 1 0 8 0 plimitpl 152 86 0 79 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 64 0 20 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 339 0 335 1 0 1 1 0 8 0 rttmr 72 7 0 7 2 2 0 1 0 8 0 nd6 48 9 0 3 1 0 1 1 0 8 0 ppxss 1128 50 0 50 8 7 1 1 0 8 1 pffrent 40 1 0 1 1 1 0 1 0 8 0 pfosfp 40 846 0 846 5 0 5 5 0 8 5 pfosfpen 112 1428 0 1428 21 0 21 21 0 8 21 pfstitem 24 46 0 26 1 0 1 1 0 8 0 pfstkey 112 46 0 26 1 0 1 1 0 8 0 pfstate 328 46 0 26 3 1 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 256 249 0 58 13 1 12 13 0 8 0 art_table 32 250 0 58 2 0 2 2 0 8 0 art_node 16 60 0 20 1 0 1 1 0 8 0 sysvmsgpl 40 10 0 2 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 203 0 193 1 0 1 1 0 8 0 shmpl 112 108 0 10 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5582 0 4127 47 0 47 47 0 8 0 ffsino 272 5582 0 4127 99 1 98 98 0 8 0 nchpl 144 9297 0 7674 61 0 61 61 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 200 5926 0 0 312 0 312 312 0 8 0 namei 1024 28314 0 28314 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 5 0 5 3 3 0 1 0 8 0 scxspl 192 26557 0 26557 18 15 3 5 0 8 3 sigapl 432 2732 0 2719 3 1 2 3 0 8 0 futexpl 56 28072 0 28072 2 1 1 1 0 8 1 knotepl 112 387 0 368 1 0 1 1 0 8 0 kqueuepl 104 494 0 492 1 0 1 1 0 8 0 pipepl 112 1526 0 1507 4 3 1 2 0 8 0 fdescpl 488 2733 0 2719 3 0 3 3 0 8 0 filepl 152 15313 0 15222 12 8 4 6 0 8 0 lockfpl 104 1007 0 1005 3 2 1 1 0 8 0 lockfspl 48 347 0 346 3 2 1 1 0 8 0 sessionpl 112 21 0 12 1 0 1 1 0 8 0 pgrppl 48 52 0 43 1 0 1 1 0 8 0 ucredpl 96 3206 0 3198 1 0 1 1 0 8 0 zombiepl 144 2720 0 2718 5 4 1 1 0 8 0 processpl 888 2749 0 2718 4 0 4 4 0 8 0 procpl 600 8397 0 8355 4 0 4 4 0 8 0 srpgc 64 9 0 9 3 3 0 1 0 8 0 sosppl 128 45 0 45 7 7 0 1 0 8 0 sockpl 384 2015 0 2003 8 6 2 3 0 8 0 mcl64k 65536 13 0 0 2 0 2 2 0 8 0 mcl16k 16384 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 15 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 135 0 0 16 0 16 16 0 8 0 mtagpl 80 4 0 0 1 0 1 1 0 8 0 mbufpl 256 186 0 0 9 0 9 9 0 8 0 bufpl 256 10947 0 3939 439 0 439 439 0 8 0 anonpl 16 223648 0 213577 105 47 58 58 0 125 12 amapchunkpl 152 15967 0 15879 40 35 5 18 0 158 0 amappl16 192 12082 0 11523 78 41 37 41 0 8 8 amappl15 184 496 0 495 1 0 1 1 0 8 0 amappl14 176 1799 0 1794 2 1 1 1 0 8 0 amappl13 168 731 0 730 2 1 1 1 0 8 0 amappl12 160 12 0 11 1 0 1 1 0 8 0 amappl11 152 61 0 50 1 0 1 1 0 8 0 amappl10 144 76 0 72 1 0 1 1 0 8 0 amappl9 136 618 0 614 1 0 1 1 0 8 0 amappl8 128 158 0 144 1 0 1 1 0 8 0 amappl7 120 40 0 35 1 0 1 1 0 8 0 amappl6 112 63 0 54 1 0 1 1 0 8 0 amappl5 104 132 0 121 1 0 1 1 0 8 0 amappl4 96 3647 0 3623 1 0 1 1 0 8 0 amappl3 88 1528 0 1517 1 0 1 1 0 8 0 amappl2 80 21453 0 21387 3 1 2 3 0 8 0 amappl1 72 67917 0 67506 26 16 10 20 0 8 0 amappl 80 8662 0 8629 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 64 109 0 10 2 0 2 2 0 8 0 uaddrrnd 24 2733 0 2719 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2733 0 2719 1 0 1 1 0 8 0 vmmpekpl 168 23737 0 23705 2 0 2 2 0 8 0 vmmpepl 168 291859 0 290320 151 68 83 87 0 357 11 vmsppl 360 2732 0 2719 2 0 2 2 0 8 0 pdppl 4096 5474 0 5438 6 0 6 6 0 8 0 pvpl 32 667271 0 654061 230 85 145 145 0 265 33 pmappl 232 2732 0 2719 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 599 0 7 17 0 17 17 0 8 0