witness: lock order reversal: 1st 0xffff800020b3a448 &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 mtx_leave+0x7 sys/kern/kern_lock.c:349 #7 exit1+0x8bf sys/kern/kern_exit.c:349 #8 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #9 userret+0x347 sys/kern/kern_sig.c:1907 #10 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #10 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #11 Xsyscall+0x128 Stopped at db_enter+0x18: addq $0x8,%rsp ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic the kernel did not panic ddb{0}> 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(ffff800020b392d8) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff80002502b170) 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(9,0,0,0,ffff800020b3a438,ffff800020b392d8) at Xresume_lapic_ltimer+0x26 mtx_leave(ffff800020b392d8) at mtx_leave+0x7 sys/kern/kern_lock.c:349 exit1(ffff800020b392d8,0,3) at exit1+0x8bf sys/kern/kern_exit.c:349 single_thread_check(ffff800020b392d8,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b392d8) at userret+0x347 sys/kern/kern_sig.c:1907 syscall(ffff80002502b4c0) at syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(ffff80002502b4c0) at syscall+0x614 sys/arch/amd64/amd64/trap.c:596 Xsyscall(6,4,157d5723a80,53,0,158b26e1600) at Xsyscall+0x128 end of kernel end trace frame: 0x1584ecf7b50, count: -13 ddb{0}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff80002502af70 rbx 0x3 rdx 0xffffffff821abff0 cpu_info_full_primary+0x1ff0 rcx 0x3 rax 0xffffffff821abff0 cpu_info_full_primary+0x1ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x3f9cf41179aae5e3 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff823392b0 w_lodata+0x4a400 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002502af60 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=355626 stat=dead flags process=1010 proc=4082000 pri=50, usrpri=78, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3a388 user=0xffff800025026000, vmspace=0xfffffd807effd9d8 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 15457 108620 24607 32767 3 0x3010 suspend syz-executor.1 15457 24405 24607 32767 2 0x4081010 syz-executor.1 63281 173370 30715 32767 3 0x10 biowait syz-executor.0 30715 409196 887 0 3 0x82 wait syz-executor.0 24607 130275 75066 32767 3 0x90 nanosleep syz-executor.1 75066 219139 887 0 3 0x82 wait syz-executor.1 68003 447956 0 0 3 0x14200 bored sosplice 887 194987 7782 0 3 0x82 thrsleep syz-fuzzer 887 191636 7782 0 3 0x4000082 nanosleep syz-fuzzer 887 408175 7782 0 3 0x4000082 thrsleep syz-fuzzer 887 24688 7782 0 3 0x4000082 thrsleep syz-fuzzer 887 372495 7782 0 3 0x4000082 thrsleep syz-fuzzer 887 321864 7782 0 3 0x4000082 thrsleep syz-fuzzer 887 285170 7782 0 3 0x4000082 thrsleep syz-fuzzer 887 418328 7782 0 3 0x4000082 kqread syz-fuzzer 887 42677 7782 0 3 0x4000082 nanosleep syz-fuzzer 887 69230 7782 0 3 0x4000082 thrsleep syz-fuzzer 7782 120729 3386 0 3 0x10008a pause ksh 3386 147521 66690 0 3 0x92 select sshd 81485 406619 1 0 3 0x100083 ttyin getty 66690 253157 1 0 3 0x80 select sshd 49436 48615 31947 73 2 0x100090 syslogd 31947 516599 1 0 3 0x100082 netio syslogd 93683 42886 1 77 3 0x100090 poll dhclient 97298 12412 1 0 3 0x80 poll dhclient 26388 54079 0 0 3 0x14200 pgzero zerothread 10328 374943 0 0 3 0x14200 aiodoned aiodoned 45173 486950 0 0 3 0x14200 syncer update 37898 319361 0 0 3 0x14200 cleaner cleaner 42493 200767 0 0 7 0x14200 reaper 12998 368411 0 0 3 0x14200 pgdaemon pagedaemon 54947 480976 0 0 3 0x14200 bored crynlk 58348 153194 0 0 3 0x14200 bored crypto 32425 356896 0 0 3 0x40014200 acpi0 acpi0 26384 234902 0 0 3 0x40014200 idle1 39864 403577 0 0 3 0x14200 bored softnet 35786 279093 0 0 3 0x14200 bored systqmp 26024 456918 0 0 3 0x14200 bored systq 50742 35709 0 0 3 0x40014200 bored softclock 91609 180555 0 0 3 0x40014200 idle0 68682 51089 0 0 3 0x14200 bored smr 1 10908 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive mutex &pr->ps_mtx r = 0 (0xffff800020b3a448) #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 Process 63281 (syz-executor.0) thread 0xffff800020b38270 (173370) exclusive rrwlock inode r = 0 (0xfffffd80693400a0) #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 ufs_ihashins+0x45 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x133 sys/ufs/ffs/ffs_vfsops.c:1352 #5 ffs_inode_alloc+0x1cf sys/ufs/ffs/ffs_alloc.c:392 #6 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1164 #7 VOP_MKDIR+0x6a sys/kern/vfs_vops.c:449 #8 domkdirat+0x121 sys/kern/vfs_syscalls.c:2974 #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 exclusive rrwlock inode r = 0 (0xfffffd8066c695f8) #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_lock+0x6e sys/kern/vfs_vnops.c:549 #5 vfs_lookup+0xe9 sys/kern/vfs_lookup.c:422 #6 namei+0x61c sys/kern/vfs_lookup.c:252 #7 domkdirat+0x75 sys/kern/vfs_syscalls.c:2959 #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 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9460 6321K 6321K 78643K 10607 0 0 pcb 23 9K 10K 78643K 416 0 0 rtable 105 3K 3K 78643K 726 0 0 ifaddr 35 10K 10K 78643K 110 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 41 0 0 iov 0 0K 16K 78643K 69 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 1547 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 13 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 46 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 7 21K 33K 78643K 888 0 0 sigio 0 0K 0K 78643K 14 0 0 proc 41 38K 70K 78643K 845 0 0 subproc 34 2K 2K 78643K 238 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 93 0 0 in_multi 33 2K 2K 78643K 185 0 0 ether_multi 1 0K 0K 78643K 6 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 380 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 30K 78643K 3713 0 0 UVM aobj 52 2K 2K 78643K 54 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 68 0 0 NDP 5 0K 0K 78643K 45 0 0 temp 113 2735K 2796K 78643K 6236 0 0 kqueue 0 0K 0K 78643K 16 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 30 0 24 1 0 1 1 0 8 0 inpcbpl 280 496 0 489 1 0 1 1 0 8 0 plimitpl 152 80 0 71 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 177 0 133 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 194 0 190 1 0 1 1 0 8 0 nd6 48 42 0 36 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 724 0 532 13 0 13 13 0 8 0 art_table 32 725 0 532 2 0 2 2 0 8 0 art_node 16 176 0 136 1 0 1 1 0 8 0 sysvmsgpl 40 25 0 9 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 44 0 34 1 0 1 1 0 8 0 shmpl 112 52 0 2 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2355 0 921 47 0 47 47 0 8 0 ffsino 272 2355 0 921 96 0 96 96 0 8 0 nchpl 144 3590 0 1972 61 0 61 61 0 8 0 uvmvnodes 72 2602 0 0 48 0 48 48 0 8 0 vnodes 200 2602 0 0 137 0 137 137 0 8 0 namei 1024 11249 0 11248 2 1 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 9695 0 9694 11 10 1 6 0 8 0 sigapl 432 1023 0 1008 3 1 2 3 0 8 0 futexpl 56 6924 0 6924 1 0 1 1 0 8 1 knotepl 112 447 0 426 1 0 1 1 0 8 0 kqueuepl 104 180 0 170 1 0 1 1 0 8 0 pipepl 112 640 0 621 2 1 1 1 0 8 0 fdescpl 488 1024 0 1008 3 0 3 3 0 8 1 filepl 152 5576 0 5472 6 1 5 5 0 8 1 lockfpl 104 161 0 161 2 1 1 1 0 8 1 lockfspl 48 56 0 56 2 1 1 1 0 8 1 sessionpl 112 29 0 19 1 0 1 1 0 8 0 pgrppl 48 46 0 36 1 0 1 1 0 8 0 ucredpl 96 1318 0 1309 1 0 1 1 0 8 0 zombiepl 144 1009 0 1008 2 1 1 1 0 8 0 processpl 888 1040 0 1008 4 0 4 4 0 8 0 procpl 600 2523 0 2479 4 0 4 4 0 8 0 srpgc 64 72 0 72 3 2 1 1 0 8 1 sosppl 128 15 0 15 4 4 0 1 0 8 0 sockpl 384 914 0 897 3 0 3 3 0 8 1 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 8 0 0 1 0 1 1 0 8 0 mcl9k 9216 9 0 0 1 0 1 1 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 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 118 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 215 0 0 12 0 12 12 0 8 0 bufpl 256 6779 0 1165 351 0 351 351 0 8 0 anonpl 16 107137 0 101213 64 23 41 42 0 125 14 amapchunkpl 152 7480 0 7385 22 13 9 12 0 158 4 amappl16 192 3742 0 3439 40 16 24 28 0 8 8 amappl15 184 346 0 345 1 0 1 1 0 8 0 amappl14 176 279 0 276 2 1 1 1 0 8 0 amappl13 168 163 0 159 1 0 1 1 0 8 0 amappl12 160 22 0 19 1 0 1 1 0 8 0 amappl11 152 90 0 76 1 0 1 1 0 8 0 amappl10 144 200 0 197 2 1 1 1 0 8 0 amappl9 136 805 0 802 1 0 1 1 0 8 0 amappl8 128 339 0 322 1 0 1 1 0 8 0 amappl7 120 200 0 191 1 0 1 1 0 8 0 amappl6 112 61 0 53 1 0 1 1 0 8 0 amappl5 104 210 0 198 1 0 1 1 0 8 0 amappl4 96 1128 0 1104 1 0 1 1 0 8 0 amappl3 88 494 0 482 1 0 1 1 0 8 0 amappl2 80 6557 0 6489 4 2 2 3 0 8 0 amappl1 72 34299 0 33858 24 15 9 19 0 8 0 amappl 80 2942 0 2904 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 53 0 2 1 0 1 1 0 8 0 uaddrrnd 24 1024 0 1008 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1024 0 1008 1 0 1 1 0 8 0 vmmpekpl 168 11878 0 11852 2 0 2 2 0 8 0 vmmpepl 168 119671 0 118282 99 31 68 76 0 357 5 vmsppl 360 1023 0 1008 2 0 2 2 0 8 0 pdppl 4096 2056 0 2016 6 0 6 6 0 8 1 pvpl 32 322313 0 313179 157 46 111 114 0 265 32 pmappl 232 1023 0 1008 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 505 0 3 15 0 15 15 0 8 0