witness: lock order reversal: 1st 0xffffffff82d0ad08 &sched_lock (&sched_lock) 2nd 0xffff80002e419a50 &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{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+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff80002e419a50,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff80002e419a50,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff80002e419a40) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff800021ccc800,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff800021ccc800,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff800021ccc800,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff800021ccc800,6,ffff80002e439a98) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff800021ccc800) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002e439bd0) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002e439bd0) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xfae772abd10, count: -9 ddb{1}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be63 rbp 0xffff80002e4397a0 rbx 0x3 rdx 0xffff800000d15740 rcx 0xffff800021ccc800 rax 0x3ffff acpi_pdirpa+0x2be62 r8 0xffff80002e439710 r9 0x8080808080808080 r10 0xd6bea8634c54d4ee r11 0x4557b1a28c1899b4 r12 0xfffffd8003a0a640 r13 0 r14 0xfffffd80039f70e0 r15 0xfffffd80031c7bc0 rip 0xffffffff81334fdc db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80002e439790 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.3) pid=91143 stat=onproc flags process=500010 proc=4002000 pri=32, usrpri=69, nice=20 forw=0xffffffffffffffff, list=0xffff800021cccd50,0xffffffff82c89948 process=0xffff80002e419940 user=0xffff80002e434000, vmspace=0xfffffd807a3cc598 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 74984 221860 12281 32767 2 0x10 syz-executor.1 11248 246006 96495 32767 3 0x90 nanoslp syz-executor.2 11248 397350 96495 32767 3 0x4000090 fsleep syz-executor.2 49704 348113 69499 32767 4 0x582010 syz-executor.3 *49704 91143 69499 32767 7 0x4502010 syz-executor.3 65114 69361 93088 32767 2 0x10 syz-executor.5 18276 11545 503 32767 2 0x10 syz-executor.0 18276 374050 503 32767 2 0x4000010 syz-executor.0 62880 180521 87657 32767 2 0x10 syz-executor.7 65501 488390 74453 32767 7 0x10 syz-executor.6 65501 137151 74453 32767 3 0x4000090 fsleep syz-executor.6 65501 354747 74453 32767 3 0x4000090 fsleep syz-executor.6 503 110507 65669 32767 3 0x90 nanoslp syz-executor.0 65669 508909 88673 0 3 0x82 wait syz-executor.0 87657 404848 43073 32767 2 0x10 syz-executor.7 43073 353883 88673 0 3 0x82 wait syz-executor.7 2668 20208 0 0 3 0x14200 bored sosplice 74453 414380 87651 32767 3 0x90 nanoslp syz-executor.6 87651 410558 88673 0 3 0x82 wait syz-executor.6 93088 320563 8775 32767 3 0x90 nanoslp syz-executor.5 8775 372792 88673 0 3 0x82 wait syz-executor.5 54618 93421 94524 32767 2 0x10 syz-executor.4 69499 275306 42968 32767 3 0x90 nanoslp syz-executor.3 42968 306268 88673 0 3 0x82 wait syz-executor.3 94524 521398 88673 0 3 0x82 wait syz-executor.4 96495 455013 41819 32767 3 0x90 nanoslp syz-executor.2 41819 33702 88673 0 3 0x82 wait syz-executor.2 12281 214876 20287 32767 3 0x90 nanoslp syz-executor.1 20287 199273 88673 0 3 0x82 wait syz-executor.1 88673 258694 43343 0 3 0x2000082 thrsleep syz-fuzzer 88673 489617 43343 0 3 0x6000082 thrsleep syz-fuzzer 88673 348924 43343 0 3 0x6000082 kqread syz-fuzzer 88673 25894 43343 0 3 0x6000082 thrsleep syz-fuzzer 88673 248656 43343 0 3 0x6000082 thrsleep syz-fuzzer 88673 293191 43343 0 3 0x6000082 wait syz-fuzzer 88673 377420 43343 0 3 0x6000082 wait syz-fuzzer 88673 220165 43343 0 3 0x6000082 thrsleep syz-fuzzer 88673 141681 43343 0 3 0x6000082 wait syz-fuzzer 88673 344926 43343 0 3 0x6000082 thrsleep syz-fuzzer 88673 25297 43343 0 3 0x6000082 wait syz-fuzzer 88673 197017 43343 0 3 0x6000082 wait syz-fuzzer 88673 201149 43343 0 3 0x6000082 wait syz-fuzzer 88673 4891 43343 0 3 0x6000082 thrsleep syz-fuzzer 88673 365599 43343 0 3 0x6000082 wait syz-fuzzer 88673 372761 43343 0 3 0x6000082 wait syz-fuzzer 43343 158559 14077 0 3 0x10008a sigsusp ksh 14077 453888 48886 0 3 0x9a kqread sshd 84891 14564 1 0 3 0x100083 ttyin getty 48886 227059 1 0 3 0x88 kqread sshd 44875 240508 33742 73 3 0x1100090 kqread syslogd 33742 147337 1 0 3 0x100082 netio syslogd 46598 175294 1 0 3 0x100080 kqread resolvd 28266 489135 44977 77 3 0x100092 kqread dhcpleased 31220 469445 44977 77 3 0x100092 kqread dhcpleased 44977 229943 1 0 3 0x80 kqread dhcpleased 5452 229718 0 0 3 0x14200 bored smr 40603 400009 0 0 2 0x14200 zerothread 30602 266023 0 0 3 0x14200 aiodoned aiodoned 25740 150700 0 0 3 0x14200 syncer update 3326 393765 0 0 3 0x14200 cleaner cleaner 6512 27861 0 0 3 0x14200 reaper reaper 10674 393755 0 0 3 0x14200 pgdaemon pagedaemon 43650 465281 0 0 3 0x14200 bored viomb 49852 50610 0 0 3 0x40014200 acpi0 acpi0 75909 474485 0 0 3 0x40014200 idle1 39634 238413 0 0 3 0x14200 bored softnet3 46012 277730 0 0 3 0x14200 bored softnet2 55504 64067 0 0 3 0x14200 bored softnet1 1632 328237 0 0 3 0x14200 bored softnet0 61377 440013 0 0 3 0x14200 bored systqmp 66698 147055 0 0 3 0x14200 bored systq 64509 270998 0 0 3 0x40014200 bored softclock 32160 313062 0 0 3 0x40014200 idle0 1 111130 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive sched_lock &sched_lock r = 0 (0xffffffff82d0ad08) #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 49704 (syz-executor.3) thread 0xffff800021ccc800 (91143) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82c795f0) #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 (0xffffffff82d0ad08) #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 65501 (syz-executor.6) thread 0xffff80002120d008 (488390) exclusive rwlock futex r = 0 (0xffffffff82bff3c0) #0 witness_lock+0x447 #1 sys_futex+0x60 sys/kern/sys_futex.c:98 #2 syscall+0x606 mi_syscall sys/sys/syscall_mi.h:110 [inline] #2 syscall+0x606 sys/arch/amd64/amd64/trap.c:623 #3 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10189 6408K 6420K 78643K 11276 0 pcb 13 12K 14K 78643K 17 0 rtable 240 6K 7K 78643K 723 0 pf 29 8K 8K 78643K 35 0 ifaddr 44 15K 15K 78643K 58 0 ifgroup 50 2K 2K 78643K 62 0 sysctl 2 0K 0K 78643K 2 0 counters 60 35K 35K 78643K 66 0 ioctlops 0 0K 2K 78643K 38 0 iov 0 0K 18K 78643K 565 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1279 80K 80K 78643K 2242 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 447 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 5901 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 25 93K 121K 78643K 8221 0 sigio 0 0K 0K 78643K 42 0 proc 56 78K 115K 78643K 1356 0 subproc 104 6K 6K 78643K 143 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 314 0 in_multi 99 7K 7K 78643K 166 0 ether_multi 1 0K 0K 78643K 6 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 73 334K 334K 78643K 73 0 exec 0 0K 1K 78643K 1376 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 418 95K 102K 78643K 83655 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 173 0 NDP 11 0K 2K 78643K 36 0 temp 74 5916K 5982K 78643K 21650 0 kqueue 12 18K 30K 78643K 628 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> 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 120 489 0 486 9 8 1 3 0 8 0 rtentry 112 154 0 41 4 0 4 4 0 8 0 unpcb 144 3943 0 3930 51 50 1 11 0 8 0 syncache 304 77 0 77 14 14 0 1 0 8 0 tcpqe 32 275 0 275 8 8 0 1 0 8 0 tcpcb 808 2701 0 2667 83 77 6 11 0 8 2 arp 120 25 0 7 1 0 1 1 0 8 0 ipq 40 7 0 7 4 4 0 1 0 8 0 ipqe 40 25 0 25 4 4 0 1 0 8 0 inpcb 368 4515 0 4478 85 80 5 15 0 8 0 nd6 136 42 0 15 1 0 1 1 0 8 0 kcovpl 48 11 0 3 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 631 0 168 32 3 29 30 0 8 0 art_table 32 632 0 168 4 0 4 4 0 8 0 art_node 16 153 0 50 1 0 1 1 0 8 0 sysvmsgpl 40 43 0 3 1 0 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 5889 0 5879 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 13404 0 11810 100 0 100 100 0 8 0 ffsino 272 13404 0 11810 107 0 107 107 0 8 0 nchpl 144 25829 0 24189 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 99830 0 99830 5 4 1 2 0 8 1 percpumem 16 46 0 3 1 0 1 1 0 8 0 kstatmem 264 28 0 6 2 0 2 2 0 8 0 scxspl 216 78661 0 78661 29 28 1 8 1 8 1 plimitpl 152 879 0 856 6 5 1 2 0 8 0 sigapl 424 8508 0 8454 7 0 7 7 0 8 0 futexpl 64 82015 0 82012 3 2 1 1 0 8 0 knotepl 120 839 0 0 18 1 17 17 0 8 0 kqueuepl 216 1597 0 1589 29 28 1 5 0 8 0 pipepl 320 1219 0 1191 34 27 7 9 0 8 4 fdescpl 496 8490 0 8454 7 2 5 6 0 8 0 filepl 152 48338 0 48105 78 62 16 20 0 8 6 lockfpl 104 4264 0 4262 1 0 1 1 0 8 0 lockfspl 48 570 0 568 1 0 1 1 0 8 0 sessionpl 144 26 0 10 1 0 1 1 0 8 0 pgrppl 48 1107 0 1091 1 0 1 1 0 8 0 ucredpl 104 5394 0 5376 1 0 1 1 0 8 0 zombiepl 144 8454 0 8454 1 0 1 1 0 8 1 processpl 1072 8508 0 8454 5 0 5 5 0 8 0 procpl 680 23707 0 23633 13 5 8 8 0 8 1 sosppl 168 107 0 107 13 13 0 1 0 8 0 sockpl 488 9176 0 9123 237 223 14 40 0 8 6 mcl64k 65536 25 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 11 0 0 1 0 1 1 0 8 0 mcl8k 8192 33 0 0 5 2 3 3 0 8 0 mcl4k 4096 41 0 0 5 1 4 4 0 8 0 mcl2k2 2112 28 0 0 2 0 2 2 0 8 0 mcl2k 2048 297 0 0 34 1 33 34 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 3894 0 0 227 0 227 227 0 8 0 bufpl 288 18725 0 12399 454 1 453 453 0 8 0 anonpl 24 897541 0 886932 114 35 79 99 0 186 0 amapchunkpl 152 263901 0 263035 93 54 39 52 0 158 2 amappl16 200 19507 0 19242 78 57 21 27 0 8 6 amappl15 192 15 0 15 2 2 0 1 0 8 0 amappl14 184 166 0 152 2 1 1 2 0 8 0 amappl13 176 16 0 16 1 1 0 1 0 8 0 amappl12 168 9168 0 9124 3 0 3 3 0 8 0 amappl11 160 64 0 53 1 0 1 1 0 8 0 amappl10 152 47 0 35 1 0 1 1 0 8 0 amappl9 144 245 0 244 1 0 1 1 0 8 0 amappl8 136 660 0 516 5 0 5 5 0 8 0 amappl7 128 102 0 91 2 0 2 2 0 8 0 amappl6 120 337 0 309 2 1 1 2 0 8 0 amappl5 112 327 0 318 1 0 1 1 0 8 0 amappl4 104 673 0 631 2 0 2 2 0 8 0 amappl3 96 52328 0 52243 7 4 3 4 0 8 0 amappl2 88 9706 0 9631 3 1 2 3 0 8 0 amappl1 80 37492 0 36962 22 9 13 22 0 8 0 amappl 88 82793 0 82540 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 8490 0 8454 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 8490 0 8454 1 0 1 1 0 8 0 vmmpekpl 168 64901 0 64855 3 0 3 3 0 8 0 vmmpepl 168 499952 0 497512 160 44 116 119 0 357 3 vmsppl 464 8489 0 8454 7 2 5 6 0 8 0 rwobjpl 56 134136 0 126741 109 2 107 107 0 8 0 pdppl 4096 16988 0 16908 266 186 80 94 0 8 0 pvpl 32 2566006 0 2548998 352 196 156 346 0 265 0 pmappl 248 8489 0 8454 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1429 0 362 31 0 31 31 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff82c29ff0) 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(ffffffff82d0ab00) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82d0ab00) at __mp_lock+0x122 sys/kern/kern_lock.c:147 wakeup_n(ffff8000212beaa0,1) at wakeup_n+0x37 sys/kern/kern_synch.c:541 futex_requeue(32b838df200,7fffffff,0,0,2) at futex_requeue+0x120 sys/kern/sys_futex.c:296 sys_futex(ffff80002120d008,ffff80002127da20,ffff80002127da70) at sys_futex+0x119 sys/kern/sys_futex.c:105 syscall(ffff80002127daf0) at syscall+0x606 mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff80002127daf0) at syscall+0x606 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7e5b0add38e0, count: -9 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x1c: addq $0x8,%rsp ddb{1}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff80002e419a50,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff80002e419a50,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff80002e419a40) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff800021ccc800,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff800021ccc800,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff800021ccc800,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff800021ccc800,6,ffff80002e439a98) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff800021ccc800) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002e439bd0) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002e439bd0) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xfae772abd10, count: -9