witness: lock order reversal: 1st 0xffffffff82cc8bd0 &sched_lock (&sched_lock) 2nd 0xffff8000ffffaf28 &pr->ps_mtx (&pr->ps_mtx) lock order "&pr->ps_mtx"(mutex) -> "&sched_lock"(sched_lock) first seen at: #0 __mp_lock+0xa2 read_rflags machine/cpufunc.h:195 [inline] #0 __mp_lock+0xa2 intr_disable machine/cpufunc.h:216 [inline] #0 __mp_lock+0xa2 sys/kern/kern_lock.c:142 #1 donice+0x178 sys/kern/kern_resource.c:218 #2 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #2 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #3 Xsyscall+0x128 lock order "&sched_lock"(sched_lock) -> "&pr->ps_mtx"(mutex) first seen at: #0 mtx_enter+0x3e sys/kern/kern_lock.c:265 #1 single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] #1 single_thread_set+0x35a sys/kern/kern_sig.c:2155 #2 sigexit+0x90 sys/kern/kern_sig.c:1562 #3 postsig+0x4a9 sys/kern/kern_sig.c:1494 #4 userret+0x16e sys/kern/kern_sig.c:1987 #5 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #5 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #6 Xsyscall+0x128 Stopped at db_enter+0x1c: 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+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff8000ffffaf28,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffffaf28,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffffaf18) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff800022cffd40,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff800022cffd40,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff800022cffd40,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff800022cffd40,6,ffff800022cefc88) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff800022cffd40) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff800022cefdc0) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800022cefdc0) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x81fb1046cc0, count: -9 ddb{0}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be63 rbp 0xffff800022cef990 rbx 0x3 rdx 0xffff800000d13cc0 rcx 0xffff800022cffd40 rax 0x3ffff acpi_pdirpa+0x2be62 r8 0xffff800022cef900 r9 0x8080808080808080 r10 0x4a92f2943da2fd5b r11 0xfbb4300061ec7d85 r12 0xfffffd8003a0a9b0 r13 0 r14 0xfffffd80039f58d0 r15 0xfffffd80031c7bc0 rip 0xffffffff81b6e27c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff800022cef980 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=14946 stat=onproc flags process=500010 proc=4002000 pri=32, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff8000211ee2b8,0xffff800022cff558 process=0xffff8000ffffae18 user=0xffff800022cea000, vmspace=0xfffffd806b91d758 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 78562 246409 72229 32767 2 0x10 syz-executor.4 8794 54292 85279 32767 4 0x582010 syz-executor.1 * 8794 14946 85279 32767 7 0x4502010 syz-executor.1 55134 8662 58084 32767 2 0x10 syz-executor.5 63629 103715 28759 32767 2 0x10 syz-executor.2 63629 291789 28759 32767 3 0x4000090 fsleep syz-executor.2 94316 283663 42954 32767 2 0x10 syz-executor.7 92264 476241 66404 32767 2 0x10 syz-executor.0 58084 188065 99706 32767 3 0x90 nanoslp syz-executor.5 99706 438053 71532 0 3 0x82 wait syz-executor.5 55452 78395 71532 0 3 0x82 wait syz-executor.3 85279 166986 12720 32767 3 0x90 nanoslp syz-executor.1 12720 522570 71532 0 3 0x82 wait syz-executor.1 42954 242282 20957 32767 3 0xb0 nanoslp syz-executor.7 20957 122794 71532 0 3 0x82 wait syz-executor.7 66404 221653 35917 32767 3 0x90 nanoslp syz-executor.0 35917 249981 71532 0 3 0x82 wait syz-executor.0 28759 148780 46116 32767 3 0x90 nanoslp syz-executor.2 46116 186395 71532 0 3 0x82 wait syz-executor.2 43502 444399 0 0 3 0x14200 bored sosplice 1243 220934 73795 32767 3 0x90 nanoslp syz-executor.6 72229 200171 11980 32767 2 0x10 syz-executor.4 73795 93352 71532 0 3 0x82 wait syz-executor.6 11980 15339 71532 0 3 0x82 wait syz-executor.4 71532 479424 46449 0 3 0x2000082 thrsleep syz-fuzzer 71532 369546 46449 0 3 0x6000082 thrsleep syz-fuzzer 71532 206394 46449 0 3 0x6000082 thrsleep syz-fuzzer 71532 65271 46449 0 3 0x6000082 wait syz-fuzzer 71532 140282 46449 0 3 0x6000082 wait syz-fuzzer 71532 267508 46449 0 3 0x6000082 kqread syz-fuzzer 71532 402799 46449 0 3 0x6000082 wait syz-fuzzer 71532 31648 46449 0 3 0x6000082 thrsleep syz-fuzzer 71532 512450 46449 0 3 0x6000082 thrsleep syz-fuzzer 71532 523516 46449 0 3 0x6000082 wait syz-fuzzer 71532 259864 46449 0 3 0x6000082 thrsleep syz-fuzzer 71532 30 46449 0 3 0x6000082 wait syz-fuzzer 71532 400118 46449 0 3 0x6000082 wait syz-fuzzer 71532 128975 46449 0 3 0x6000082 thrsleep syz-fuzzer 71532 407630 46449 0 3 0x6000082 wait syz-fuzzer 71532 381619 46449 0 3 0x6000082 wait syz-fuzzer 46449 238780 39900 0 3 0x10008a sigsusp ksh 39900 409110 14083 0 3 0x9a kqread sshd 95061 392081 1 0 3 0x100083 ttyin getty 14083 489380 1 0 3 0x88 kqread sshd 91278 359252 21296 73 3 0x1100090 kqread syslogd 21296 96896 1 0 3 0x100082 netio syslogd 12535 240546 1 0 3 0x100080 kqread resolvd 85134 416693 36086 77 3 0x100092 kqread dhcpleased 3255 503403 36086 77 3 0x100092 kqread dhcpleased 36086 378976 1 0 3 0x80 kqread dhcpleased 37303 475775 0 0 3 0x14200 bored smr 75575 501490 0 0 2 0x14200 zerothread 920 504601 0 0 3 0x14200 aiodoned aiodoned 75318 386146 0 0 3 0x14200 syncer update 38026 119327 0 0 3 0x14200 cleaner cleaner 7877 461039 0 0 3 0x14200 reaper reaper 75319 469490 0 0 3 0x14200 pgdaemon pagedaemon 51732 297720 0 0 3 0x14200 bored viomb 99582 253502 0 0 3 0x40014200 acpi0 acpi0 33550 281850 0 0 3 0x40014200 idle1 23863 324128 0 0 3 0x14200 bored softnet3 63798 284900 0 0 3 0x14200 bored softnet2 58523 261227 0 0 3 0x14200 bored softnet1 79804 251022 0 0 3 0x14200 bored softnet0 45826 314387 0 0 3 0x14200 bored systqmp 31588 392549 0 0 3 0x14200 bored systq 31264 62505 0 0 3 0x40014200 bored softclock 71630 29 0 0 3 0x40014200 idle0 1 479984 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive sched_lock &sched_lock r = 0 (0xffffffff82cc8bd0) #0 witness_lock+0x447 #1 single_thread_set+0x179 sys/kern/kern_sig.c:2113 #2 sigexit+0x90 sys/kern/kern_sig.c:1562 #3 postsig+0x4a9 sys/kern/kern_sig.c:1494 #4 userret+0x16e sys/kern/kern_sig.c:1987 #5 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #5 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #6 Xsyscall+0x128 Process 8794 (syz-executor.1) thread 0xffff800022cffd40 (14946) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82ca0228) #0 witness_lock+0x447 #1 postsig+0x49e sys/kern/kern_sig.c:1500 #2 userret+0x16e sys/kern/kern_sig.c:1987 #3 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #3 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #4 Xsyscall+0x128 exclusive sched_lock &sched_lock r = 0 (0xffffffff82cc8bd0) #0 witness_lock+0x447 #1 single_thread_set+0x179 sys/kern/kern_sig.c:2113 #2 sigexit+0x90 sys/kern/kern_sig.c:1562 #3 postsig+0x4a9 sys/kern/kern_sig.c:1494 #4 userret+0x16e sys/kern/kern_sig.c:1987 #5 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #5 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10195 6409K 6420K 78643K 11390 0 pcb 13 12K 14K 78643K 17 0 rtable 254 7K 7K 78643K 2162 0 pf 29 8K 8K 78643K 107 0 ifaddr 44 15K 16K 78643K 206 0 ifgroup 50 2K 2K 78643K 206 0 sysctl 3 1K 2K 78643K 7 0 counters 60 35K 35K 78643K 138 0 ioctlops 0 0K 2K 78643K 188 0 iov 0 0K 18K 78643K 1913 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1279 80K 80K 78643K 4424 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 227 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 22 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 24 89K 121K 78643K 16573 0 sigio 0 0K 0K 78643K 372 0 proc 56 78K 115K 78643K 2626 0 subproc 104 6K 6K 78643K 611 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 1019 0 in_multi 99 7K 7K 78643K 675 0 ether_multi 1 0K 0K 78643K 21 0 mrt 1 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 109 493K 493K 78643K 109 0 exec 0 0K 1K 78643K 3691 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 64K 78643K 10 0 UVM amap 412 87K 104K 78643K 163550 0 UVM aobj 131 4K 4K 78643K 135 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 361 0 NDP 11 0K 2K 78643K 144 0 temp 74 5920K 6000K 78643K 45340 0 kqueue 12 18K 32K 78643K 1343 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 824 0 821 11 10 1 4 0 8 0 rtentry 112 583 0 463 4 0 4 4 0 8 0 unpcb 144 7821 0 7808 78 70 8 8 0 8 7 syncache 304 220 0 220 27 27 0 1 0 8 0 tcpqe 32 428 0 428 26 25 1 2 0 8 1 tcpcb 808 18435 0 18402 183 172 11 17 0 8 5 arp 120 101 0 82 1 0 1 1 0 8 0 ipq 40 70 0 69 7 6 1 1 0 8 0 ipqe 40 266 0 265 7 6 1 1 0 8 0 inpcb 368 25854 0 25813 210 199 11 21 0 8 6 nd6 136 179 0 146 4 2 2 2 0 8 0 kcovpl 48 47 0 39 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 2329 0 1833 36 4 32 32 0 8 0 art_table 32 2330 0 1833 5 0 5 5 0 8 0 art_node 16 582 0 472 1 0 1 1 0 8 0 sysvmsgpl 40 42 0 39 2 1 1 1 0 8 0 semupl 112 6 0 6 1 1 0 1 0 8 0 semapl 112 10 0 0 1 0 1 1 0 8 0 shmpl 112 132 0 4 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 22404 0 20947 92 0 92 92 0 8 0 ffsino 272 22404 0 20947 98 0 98 98 0 8 0 nchpl 144 43456 0 41814 63 0 63 63 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 139558 0 139558 2 1 1 2 0 8 1 percpumem 16 82 0 39 1 0 1 1 0 8 0 kstatmem 264 100 0 78 2 0 2 2 0 8 0 scxspl 216 125580 0 125580 39 38 1 8 1 8 1 plimitpl 152 2556 0 2533 22 20 2 2 0 8 1 sigapl 424 16788 0 16734 7 0 7 7 0 8 0 futexpl 64 148537 0 148536 3 2 1 1 0 8 0 knotepl 120 891 0 0 13 0 13 13 0 8 0 kqueuepl 216 3594 0 3586 72 67 5 8 0 8 4 pipepl 320 3705 0 3677 93 85 8 8 0 8 5 fdescpl 496 16770 0 16735 7 2 5 6 0 8 0 filepl 152 106296 0 106062 132 115 17 20 0 8 5 lockfpl 104 2130 0 2128 1 0 1 1 0 8 0 lockfspl 48 613 0 611 1 0 1 1 0 8 0 sessionpl 144 62 0 46 1 0 1 1 0 8 0 pgrppl 48 347 0 331 1 0 1 1 0 8 0 ucredpl 104 14700 0 14682 1 0 1 1 0 8 0 zombiepl 144 16736 0 16734 1 0 1 1 0 8 0 processpl 1072 16788 0 16734 5 1 4 5 0 8 0 procpl 680 45911 0 45840 29 21 8 8 0 8 1 sosppl 168 290 0 287 18 17 1 1 0 8 0 sockpl 488 35126 0 35074 393 375 18 32 0 8 8 mcl64k 65536 29 0 0 3 0 3 3 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 33 0 0 4 1 3 3 0 8 0 mcl4k 4096 89 0 0 4 1 3 3 0 8 0 mcl2k2 2112 9 0 0 1 0 1 1 0 8 0 mcl2k 2048 467 0 0 33 10 23 33 0 8 0 mtagpl 96 8 0 0 1 0 1 1 0 8 0 mbufpl 256 1517 0 0 64 0 64 64 0 8 0 bufpl 288 24943 0 18615 453 0 453 453 0 8 0 anonpl 24 1666286 0 1654733 243 151 92 100 0 186 0 amapchunkpl 152 526913 0 526091 138 97 41 52 0 158 1 amappl16 200 33895 0 33566 216 197 19 39 0 8 0 amappl15 192 19 0 19 3 3 0 1 0 8 0 amappl14 184 278 0 263 2 1 1 2 0 8 0 amappl13 176 17 0 16 1 0 1 1 0 8 0 amappl12 168 17987 0 17950 2 0 2 2 0 8 0 amappl11 160 57 0 47 1 0 1 1 0 8 0 amappl10 152 69 0 56 1 0 1 1 0 8 0 amappl9 144 308 0 307 1 0 1 1 0 8 0 amappl8 136 833 0 664 7 1 6 6 0 8 0 amappl7 128 155 0 140 1 0 1 1 0 8 0 amappl6 120 650 0 621 1 0 1 1 0 8 0 amappl5 112 708 0 699 1 0 1 1 0 8 0 amappl4 104 1090 0 1048 2 0 2 2 0 8 0 amappl3 96 101489 0 101407 7 4 3 4 0 8 0 amappl2 88 17771 0 17690 3 1 2 3 0 8 0 amappl1 80 69563 0 69035 22 10 12 22 0 8 0 amappl 88 162234 0 161993 7 0 7 7 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 134 0 4 3 0 3 3 0 8 0 uaddrrnd 24 16770 0 16735 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 16770 0 16735 1 0 1 1 0 8 0 vmmpekpl 168 129732 0 129662 4 0 4 4 0 8 0 vmmpepl 168 985790 0 983295 302 173 129 129 0 357 11 vmsppl 464 16769 0 16735 7 2 5 6 0 8 0 rwobjpl 56 245699 0 238205 119 10 109 112 0 8 0 pdppl 4096 33548 0 33470 548 466 82 94 0 8 4 pvpl 32 4792267 0 4774391 469 294 175 334 0 265 0 pmappl 248 16769 0 16735 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1769 0 877 26 0 26 26 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff8000ffffaf28,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffffaf28,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffffaf18) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff800022cffd40,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff800022cffd40,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff800022cffd40,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff800022cffd40,6,ffff800022cefc88) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff800022cffd40) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff800022cefdc0) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800022cefdc0) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x81fb1046cc0, count: -9 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1e sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff82cc89c8) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82cc89c8) at __mp_lock+0x122 sys/kern/kern_lock.c:147 sleep_finish(2,1) at sleep_finish+0x142 sys/kern/kern_synch.c:398 sys_nanosleep(ffff800021268ac0,ffff8000295bf910,ffff8000295bf960) at sys_nanosleep+0x1f5 sys/kern/kern_time.c:297 syscall(ffff8000295bf9e0) at syscall+0x606 mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff8000295bf9e0) at syscall+0x606 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7e1acb6b9d50, count: -8