witness: lock order reversal: 1st 0xffffffff82cc8bd0 &sched_lock (&sched_lock) 2nd 0xffff80002818eb08 &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(ffff80002818eb08,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff80002818eb08,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff80002818eaf8) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff800021289ab0,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff800021289ab0,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff800021289ab0,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff800021289ab0,6,ffff80002e4651d8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff800021289ab0) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002e465310) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002e465310) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x33be878eba0, count: -9 ddb{0}> show registers rdi 0x3 rsi 0xffffffff82bf22f0 __sancov_gen_cov_switch_values.134 rbp 0xffff80002e464ee0 rbx 0x3 rdx 0 rcx 0xffff800021289ab0 rax 0xffffffff82c05ff0 cpu_info_full_primary+0x1ff0 r8 0xffff80002e464e50 r9 0x8080808080808080 r10 0xbccaf591eac82248 r11 0xb24634aebc1f914e r12 0xfffffd8003a0a4e0 r13 0 r14 0xfffffd80039f40c0 r15 0xfffffd80031c7bc0 rip 0xffffffff81b6e27c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80002e464ed0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.3) pid=205541 stat=onproc flags process=500010 proc=4002000 pri=32, usrpri=77, nice=20 forw=0xffffffffffffffff, list=0xffff800021288570,0xffff800021289020 process=0xffff80002818e9f8 user=0xffff80002e460000, vmspace=0xfffffd806b6b4930 estcpu=27, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 32138 158966 16072 32767 2 0x10 syz-executor.7 32138 69224 16072 32767 3 0x4000090 fsleep syz-executor.7 70460 397982 53928 32767 2 0x10 syz-executor.6 70460 451194 53928 32767 3 0x4000090 fsleep syz-executor.6 42141 229563 9009 32767 2 0x10 syz-executor.4 42141 149433 9009 32767 3 0x4000090 fsleep syz-executor.4 84926 69603 43887 32767 4 0x582010 syz-executor.3 *84926 205541 43887 32767 7 0x4502010 syz-executor.3 84926 379866 43887 32767 4 0x4580090 fsleep syz-executor.3 19184 186602 64601 32767 2 0x10 syz-executor.5 19184 130727 64601 32767 3 0x4000090 fsleep syz-executor.5 26021 338165 26099 32767 7 0x10 syz-executor.2 98256 72423 2744 32767 2 0x10 syz-executor.1 98256 344732 2744 32767 2 0x4000090 syz-executor.1 30658 355325 91873 32767 2 0x10 syz-executor.0 30658 110684 91873 32767 3 0x4000090 fsleep syz-executor.0 30658 165898 91873 32767 2 0x4000010 syz-executor.0 26099 474840 47801 32767 3 0x90 nanoslp syz-executor.2 47801 405317 91933 0 3 0x82 wait syz-executor.2 2744 154068 86961 32767 2 0x10 syz-executor.1 86961 405738 91933 0 3 0x82 wait syz-executor.1 43887 324279 5686 32767 3 0x90 nanoslp syz-executor.3 5686 201652 91933 0 3 0x82 wait syz-executor.3 9009 507364 30345 32767 3 0x90 nanoslp syz-executor.4 30345 441768 91933 0 3 0x82 wait syz-executor.4 16072 174747 14052 32767 3 0x90 nanoslp syz-executor.7 14052 244585 91933 0 3 0x82 wait syz-executor.7 53928 336201 55517 32767 3 0x90 nanoslp syz-executor.6 55517 522646 91933 0 3 0x82 wait syz-executor.6 91873 29948 83781 32767 2 0x10 syz-executor.0 83781 168205 91933 0 3 0x82 wait syz-executor.0 64601 466882 58371 32767 3 0x90 nanoslp syz-executor.5 58371 242035 91933 0 3 0x82 wait syz-executor.5 73943 36654 0 0 3 0x14200 bored sosplice 91933 156953 89420 0 3 0x2000082 thrsleep syz-fuzzer 91933 375200 89420 0 3 0x6000082 thrsleep syz-fuzzer 91933 84081 89420 0 3 0x6000082 thrsleep syz-fuzzer 91933 15875 89420 0 3 0x6000082 thrsleep syz-fuzzer 91933 412833 89420 0 3 0x6000082 thrsleep syz-fuzzer 91933 444877 89420 0 3 0x6000082 wait syz-fuzzer 91933 275006 89420 0 3 0x6000082 kqread syz-fuzzer 91933 462271 89420 0 3 0x6000082 wait syz-fuzzer 91933 199665 89420 0 3 0x6000082 wait syz-fuzzer 91933 222360 89420 0 3 0x6000082 thrsleep syz-fuzzer 91933 161519 89420 0 3 0x6000082 thrsleep syz-fuzzer 91933 491441 89420 0 3 0x6000082 wait syz-fuzzer 91933 246446 89420 0 3 0x6000082 wait syz-fuzzer 91933 275908 89420 0 3 0x6000082 wait syz-fuzzer 91933 246071 89420 0 3 0x6000082 wait syz-fuzzer 91933 98847 89420 0 3 0x6000082 wait syz-fuzzer 89420 372011 38876 0 3 0x10008a sigsusp ksh 38876 211188 67838 0 3 0x9a kqread sshd 53168 492988 1 0 3 0x100083 ttyin getty 67838 155008 1 0 3 0x88 kqread sshd 37075 259729 81279 73 3 0x1100090 kqread syslogd 81279 264756 1 0 3 0x100082 netio syslogd 24542 30078 1 0 3 0x100080 kqread resolvd 6935 55409 20627 77 3 0x100092 kqread dhcpleased 41703 446095 20627 77 3 0x100092 kqread dhcpleased 20627 193158 1 0 3 0x80 kqread dhcpleased 82417 392110 0 0 3 0x14200 bored smr 44753 59421 0 0 2 0x14200 zerothread 21118 61738 0 0 3 0x14200 aiodoned aiodoned 16348 108963 0 0 3 0x14200 syncer update 74899 492896 0 0 3 0x14200 cleaner cleaner 71883 494772 0 0 3 0x14200 reaper reaper 65248 405458 0 0 3 0x14200 pgdaemon pagedaemon 47118 202592 0 0 3 0x14200 bored viomb 59935 211078 0 0 3 0x40014200 acpi0 acpi0 77467 271628 0 0 3 0x40014200 idle1 96936 166050 0 0 3 0x14200 bored softnet3 35663 162524 0 0 3 0x14200 bored softnet2 90553 520972 0 0 3 0x14200 bored softnet1 97356 60266 0 0 3 0x14200 bored softnet0 10703 424187 0 0 3 0x14200 bored systqmp 98823 194950 0 0 3 0x14200 bored systq 27109 416707 0 0 3 0x40014200 bored softclock 35769 448870 0 0 3 0x40014200 idle0 1 59892 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 84926 (syz-executor.3) thread 0xffff800021289ab0 (205541) 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 10208 6411K 6420K 78643K 11404 0 pcb 13 10K 12K 78643K 15 0 rtable 242 6K 7K 78643K 2087 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 1K 78643K 3 0 counters 60 35K 35K 78643K 138 0 ioctlops 0 0K 2K 78643K 428 0 iov 0 0K 18K 78643K 2192 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1279 80K 80K 78643K 5838 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 325 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 6461 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 26 97K 109K 78643K 25662 0 sigio 0 0K 0K 78643K 1162 0 proc 56 78K 115K 78643K 6345 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 1291 0 in_multi 99 7K 7K 78643K 770 0 ether_multi 1 0K 0K 78643K 32 0 mrt 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 187 837K 837K 78643K 187 0 exec 0 0K 1K 78643K 5115 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 501 97K 109K 78643K 251443 0 UVM aobj 131 11K 11K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 636 0 NDP 11 0K 2K 78643K 144 0 temp 74 5920K 6000K 78643K 65918 0 kqueue 12 18K 32K 78643K 2183 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 1399 0 1396 19 18 1 5 0 8 0 rtentry 112 584 0 470 4 0 4 4 0 8 0 unpcb 144 13909 0 13896 159 158 1 8 0 8 0 syncache 304 294 0 294 48 48 0 1 0 8 0 tcpqe 32 328 0 328 34 34 0 1 0 8 0 tcpcb 808 8138 0 8114 236 226 10 10 0 8 6 arp 120 101 0 82 1 0 1 1 0 8 0 ipq 40 38 0 38 12 12 0 1 0 8 0 ipqe 40 182 0 182 12 12 0 1 0 8 0 inpcb 368 37464 0 37435 318 308 10 19 0 8 6 nd6 136 180 0 153 3 2 1 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 2345 0 1868 44 14 30 31 0 8 0 art_table 32 2346 0 1868 4 0 4 4 0 8 0 art_node 16 583 0 479 1 0 1 1 0 8 0 sysvmsgpl 40 29 0 23 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 6456 0 6446 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 35156 0 33707 91 0 91 91 0 8 0 ffsino 272 35156 0 33707 97 0 97 97 0 8 0 nchpl 144 69022 0 67379 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 240077 0 240077 15 14 1 3 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 207895 0 207895 61 60 1 8 1 8 1 plimitpl 152 2933 0 2909 26 25 1 2 0 8 0 sigapl 424 25871 0 25816 7 0 7 7 0 8 0 futexpl 64 234302 0 234296 9 8 1 1 0 8 0 knotepl 120 1504 0 0 18 2 16 17 0 8 0 kqueuepl 216 7566 0 7558 99 98 1 8 0 8 0 pipepl 320 10246 0 10217 177 174 3 13 0 8 0 fdescpl 496 25853 0 25816 6 1 5 6 0 8 0 filepl 152 178779 0 178542 270 257 13 22 0 8 3 lockfpl 104 4588 0 4586 6 5 1 2 0 8 0 lockfspl 48 1140 0 1138 1 0 1 1 0 8 0 sessionpl 144 62 0 46 1 0 1 1 0 8 0 pgrppl 48 941 0 925 1 0 1 1 0 8 0 ucredpl 104 21204 0 21186 1 0 1 1 0 8 0 zombiepl 144 25816 0 25816 1 0 1 1 0 8 1 processpl 1072 25871 0 25816 4 0 4 4 0 8 0 procpl 680 70822 0 70743 56 48 8 8 0 8 1 sosppl 168 349 0 349 33 33 0 1 0 8 0 sockpl 488 53628 0 53585 801 786 15 37 0 8 7 mcl64k 65536 41 0 0 4 1 3 3 0 8 0 mcl16k 16384 42 0 0 4 1 3 3 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 25 0 0 2 0 2 2 0 8 0 mcl8k 8192 29 0 0 4 1 3 3 0 8 0 mcl4k 4096 113 0 0 5 1 4 4 0 8 0 mcl2k2 2112 39 0 0 3 0 3 3 0 8 0 mcl2k 2048 472 0 0 39 22 17 39 0 8 0 mtagpl 96 10 0 0 1 0 1 1 0 8 0 mbufpl 256 1991 0 0 67 0 67 67 0 8 0 bufpl 288 41649 0 35321 453 0 453 453 0 8 0 anonpl 24 2608650 0 2596799 231 130 101 107 0 186 0 amapchunkpl 152 792457 0 791510 170 132 38 50 0 158 0 amappl16 200 60324 0 60022 330 301 29 36 0 8 9 amappl15 192 10 0 9 1 0 1 1 0 8 0 amappl14 184 267 0 253 2 1 1 2 0 8 0 amappl13 176 43 0 43 11 11 0 1 0 8 0 amappl12 168 27072 0 27028 3 1 2 3 0 8 0 amappl11 160 55 0 44 1 0 1 1 0 8 0 amappl10 152 72 0 59 1 0 1 1 0 8 0 amappl9 144 438 0 437 1 0 1 1 0 8 0 amappl8 136 1214 0 990 8 0 8 8 0 8 0 amappl7 128 163 0 149 2 0 2 2 0 8 0 amappl6 120 735 0 708 1 0 1 1 0 8 0 amappl5 112 862 0 852 1 0 1 1 0 8 0 amappl4 104 1222 0 1174 2 0 2 2 0 8 0 amappl3 96 156050 0 155947 3 0 3 3 0 8 0 amappl2 88 28174 0 28093 3 1 2 3 0 8 0 amappl1 80 99704 0 99167 22 10 12 22 0 8 0 amappl 88 249810 0 249533 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 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 25853 0 25816 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 25853 0 25816 1 0 1 1 0 8 0 vmmpekpl 168 223960 0 223904 4 0 4 4 0 8 0 vmmpepl 168 1499489 0 1496832 402 278 124 133 0 357 0 vmsppl 464 25852 0 25816 6 1 5 5 0 8 0 rwobjpl 56 374090 0 366530 120 9 111 112 0 8 0 pdppl 4096 51714 0 51632 792 710 82 88 0 8 0 pvpl 32 7338533 0 7319727 750 564 186 337 0 265 10 pmappl 248 25852 0 25816 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 2232 0 1348 27 0 27 27 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(ffff80002818eb08,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff80002818eb08,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff80002818eaf8) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff800021289ab0,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff800021289ab0,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff800021289ab0,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff800021289ab0,6,ffff80002e4651d8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff800021289ab0) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002e465310) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002e465310) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x33be878eba0, 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(ffffffff82ca0020) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82ca0020) at __mp_lock+0x122 sys/kern/kern_lock.c:147 syscall(ffff80002e4173d0) at syscall+0x5cd mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff80002e4173d0) at syscall+0x5cd sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7631c0923890, count: -6