witness: lock order reversal: 1st 0xffff800020b3ab38 &pr->ps_mtx (&pr->ps_mtx) 2nd 0xffffffff8236c9d8 &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 calcru+0x18b calctsru sys/kern/kern_resource.c:394 [inline] #6 calcru+0x18b sys/kern/kern_resource.c:420 #7 exit1+0x737 sys/kern/kern_exit.c:301 #8 sys_exit+0x17 sys/kern/kern_exit.c:94 #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 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(ffffffff8236c9d8,9,0) at witness_checkorder+0xffc witness_debugger sys/kern/subr_witness.c:2504 [inline] witness_checkorder(ffffffff8236c9d8,9,0) at witness_checkorder+0xffc sys/kern/subr_witness.c:1084 __mp_lock(ffffffff8236c7d0) at __mp_lock+0xa1 schedclock(ffff800020b384c8) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800022c07200) 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,ffffffff81a14c19,0,0,0,0) at Xresume_lapic_ltimer+0x26 calcru(ffff800020b3aba0,fffffd806dc16c68,fffffd806dc16c78,0) at calcru+0x18b calctsru sys/kern/kern_resource.c:394 [inline] calcru(ffff800020b3aba0,fffffd806dc16c68,fffffd806dc16c78,0) at calcru+0x18b sys/kern/kern_resource.c:420 exit1(ffff800020b384c8,100,1) at exit1+0x737 sys/kern/kern_exit.c:301 sys_exit(ffff800020b384c8,ffff800022c07410,ffff800022c07480) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800022c074f0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800022c074f0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,11ec64b5f110,1,16,1) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff44b0, count: -12 ddb{1}> show registers rdi 0x3 rsi 0xffffffff821c7a20 __sancov_gen_cov_switch_values.122 rbp 0xffff800022c07000 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff813b9985 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0x71c43f7eaf6fdbcc r12 0xfffffd8002662340 r13 0xc r14 0xffffffff8230cb70 w_lodata+0x4b530 r15 0xffffffff82318670 w_lodata+0x57030 rip 0xffffffff81e8beb8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022c06ff0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (ifconfig) pid=67826 stat=dead flags process=a proc=2000 pri=62, usrpri=62, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3aa78 user=0xffff800022c02000, vmspace=0xfffffd807effeca8 estcpu=12, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 82781 20797 37564 0 3 0x10008a pause sh 37564 466851 19538 0 3 0x80 wait syz-executor.1 19538 285462 30056 0 3 0x82 wait syz-executor.1 61808 22668 60725 32767 3 0x90 piperd syz-executor.0 60725 512211 30056 0 3 0x82 wait syz-executor.0 49834 58402 0 0 3 0x14200 bored sosplice 30056 47232 19176 0 3 0x82 thrsleep syz-fuzzer 30056 427191 19176 0 3 0x4000082 nanosleep syz-fuzzer 30056 91110 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 870 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 236834 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 339921 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 398 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 463482 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 99672 19176 0 3 0x4000082 thrsleep syz-fuzzer 30056 353285 19176 0 3 0x4000082 kqread syz-fuzzer 19176 307642 55523 0 3 0x10008a pause ksh 55523 157338 91101 0 3 0x92 select sshd 45062 251260 1 0 3 0x100083 ttyin getty 91101 352668 1 0 3 0x80 select sshd 5276 390925 5093 73 7 0x100090 syslogd 5093 229245 1 0 3 0x100082 netio syslogd 48738 283461 1 77 3 0x100090 poll dhclient 73621 291139 1 0 3 0x80 poll dhclient 33472 205846 0 0 3 0x14200 pgzero zerothread 67075 268171 0 0 3 0x14200 aiodoned aiodoned 58991 207612 0 0 3 0x14200 syncer update 68014 84559 0 0 3 0x14200 cleaner cleaner 5515 157881 0 0 3 0x14200 reaper reaper 10691 136272 0 0 3 0x14200 pgdaemon pagedaemon 64175 447656 0 0 3 0x14200 bored crynlk 7129 133330 0 0 3 0x14200 bored crypto 88227 84532 0 0 3 0x40014200 acpi0 acpi0 79825 83846 0 0 3 0x40014200 idle1 53077 24252 0 0 3 0x14200 bored softnet 282 149542 0 0 3 0x14200 bored systqmp 99761 417497 0 0 3 0x14200 bored systq 34640 362027 0 0 3 0x40014200 bored softclock 78477 282631 0 0 3 0x40014200 idle0 82527 29634 0 0 3 0x14200 bored smr 1 129261 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 (0xffff800020b3ab38) #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 exit1+0x722 sys/kern/kern_exit.c:300 #4 sys_exit+0x17 sys/kern/kern_exit.c:94 #5 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] #5 syscall+0x552 sys/arch/amd64/amd64/trap.c:574 #6 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9454 6319K 6321K 78643K 10606 0 0 pcb 23 9K 10K 78643K 385 0 0 rtable 83 2K 3K 78643K 736 0 0 ifaddr 29 9K 10K 78643K 110 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 37 0 0 iov 0 0K 28K 78643K 36 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 1605 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 8 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 25 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 7 21K 33K 78643K 672 0 0 sigio 0 0K 0K 78643K 11 0 0 proc 41 38K 70K 78643K 843 0 0 subproc 34 2K 2K 78643K 255 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 80 0 0 in_multi 22 1K 2K 78643K 183 0 0 ether_multi 1 0K 0K 78643K 2 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 54 238K 238K 78643K 54 0 0 exec 0 0K 1K 78643K 379 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 86 21K 29K 78643K 2996 0 0 UVM aobj 20 2K 2K 78643K 20 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 18 0 0 NDP 4 0K 0K 78643K 45 0 0 temp 93 2725K 2790K 78643K 5848 0 0 kqueue 0 0K 0K 78643K 4 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 30 0 26 1 0 1 1 0 8 0 inpcbpl 280 303 0 296 1 0 1 1 0 8 0 plimitpl 152 66 0 57 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 177 0 144 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 96 0 92 1 0 1 1 0 8 0 nd6 48 42 0 39 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 727 0 579 12 0 12 12 0 8 0 art_table 32 728 0 579 2 0 2 2 0 8 0 art_node 16 176 0 146 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 2 1 1 0 1 0 8 0 semapl 112 23 0 13 1 0 1 1 0 8 0 shmpl 112 18 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2148 0 719 47 0 47 47 0 8 0 ffsino 272 2148 0 719 96 0 96 96 0 8 0 nchpl 144 3101 0 1481 61 0 61 61 0 8 0 uvmvnodes 72 2412 0 0 44 0 44 44 0 8 0 vnodes 200 2412 0 0 127 0 127 127 0 8 0 namei 1024 10176 0 10176 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 7823 0 7823 9 8 1 6 0 8 1 sigapl 432 804 0 788 4 2 2 3 0 8 0 futexpl 56 5112 0 5112 1 0 1 1 0 8 1 knotepl 112 454 0 433 1 0 1 1 0 8 0 kqueuepl 104 139 0 137 1 0 1 1 0 8 0 pipepl 112 532 0 513 3 2 1 2 0 8 0 fdescpl 488 805 0 789 3 0 3 3 0 8 0 filepl 152 4812 0 4717 7 2 5 6 0 8 1 lockfpl 104 174 0 174 2 1 1 1 0 8 1 lockfspl 48 53 0 53 2 1 1 1 0 8 1 sessionpl 112 30 0 20 1 0 1 1 0 8 0 pgrppl 48 36 0 26 1 0 1 1 0 8 0 ucredpl 96 1366 0 1358 1 0 1 1 0 8 0 zombiepl 144 789 0 788 2 1 1 1 0 8 0 processpl 888 821 0 788 4 0 4 4 0 8 0 procpl 600 1812 0 1770 4 0 4 4 0 8 0 srpgc 64 78 0 78 2 1 1 1 0 8 1 sosppl 128 15 0 15 2 1 1 1 0 8 1 sockpl 384 677 0 660 3 0 3 3 0 8 1 mcl64k 65536 6 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 111 0 0 13 0 13 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 203 0 0 12 0 12 12 0 8 0 bufpl 256 6284 0 1159 321 0 321 321 0 8 0 anonpl 16 80123 0 75124 39 14 25 38 0 125 0 amapchunkpl 152 6220 0 6101 13 8 5 9 0 158 0 amappl16 192 2741 0 2459 28 11 17 27 0 8 2 amappl15 184 14 0 14 2 2 0 1 0 8 0 amappl14 176 118 0 113 2 1 1 1 0 8 0 amappl13 168 45 0 41 1 0 1 1 0 8 0 amappl12 160 104 0 101 1 0 1 1 0 8 0 amappl11 152 226 0 212 1 0 1 1 0 8 0 amappl10 144 170 0 168 2 1 1 1 0 8 0 amappl9 136 747 0 740 1 0 1 1 0 8 0 amappl8 128 283 0 267 1 0 1 1 0 8 0 amappl7 120 158 0 147 1 0 1 1 0 8 0 amappl6 112 183 0 174 1 0 1 1 0 8 0 amappl5 104 295 0 284 1 0 1 1 0 8 0 amappl4 96 866 0 845 1 0 1 1 0 8 0 amappl3 88 285 0 275 1 0 1 1 0 8 0 amappl2 80 4641 0 4585 4 2 2 3 0 8 0 amappl1 72 29235 0 28795 23 13 10 19 0 8 0 amappl 80 2237 0 2201 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 19 0 0 1 0 1 1 0 8 0 uaddrrnd 24 805 0 788 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 805 0 788 1 0 1 1 0 8 0 vmmpekpl 168 10461 0 10433 2 0 2 2 0 8 0 vmmpepl 168 95401 0 94094 101 34 67 75 0 357 7 vmsppl 360 804 0 788 2 0 2 2 0 8 0 pdppl 4096 1618 0 1576 6 0 6 6 0 8 0 pvpl 32 262282 0 254051 112 29 83 102 0 265 7 pmappl 232 804 0 788 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 473 0 3 14 0 14 14 0 8 0