witness: lock order reversal: 1st 0xffff800020b8c450 &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 calcru+0x7 sys/kern/kern_resource.c:417 #7 sys_exit+0x17 sys/kern/kern_exit.c:94 #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 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(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(ffff800020b672a0) 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,ffff800020b8c440,0,ffff800020b8c390,2000) at Xresume_lapic_ltimer+0x26 calcru(ffff800020b392d8,0,1,ffff800020b392d8) at calcru+0x7 sys/kern/kern_resource.c:417 sys_exit(ffff800020b392d8,ffff800020b67420,ffff800020b67490) at sys_exit+0x17 sys/kern/kern_exit.c:94 syscall(ffff800020b67500) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020b67500) at syscall+0x552 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,1,0,1,0,7f7fffff7014) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff6fe0, count: -11 ddb{1}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff800020b670a0 rbx 0x3 rdx 0xffff800020ab0ff0 rcx 0x3 rax 0xffff800020ab0ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xe6170941460525f0 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff82334be0 w_lodata+0x45d30 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b67090 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=157121 stat=dead flags process=1018 proc=2000 pri=50, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8c390 user=0xffff800020b62000, vmspace=0xfffffd807effdb40 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 16757 277034 20266 32767 3 0x90 nanosleep syz-executor.0 20266 223589 15015 0 3 0x82 wait syz-executor.0 84515 403875 0 0 3 0x14200 bored sosplice 15015 324741 37861 0 3 0x82 thrsleep syz-fuzzer 15015 156477 37861 0 3 0x4000082 nanosleep syz-fuzzer 15015 31989 37861 0 3 0x4000082 thrsleep syz-fuzzer 15015 51611 37861 0 3 0x4000082 kqread syz-fuzzer 15015 416289 37861 0 3 0x4000082 thrsleep syz-fuzzer 15015 190780 37861 0 3 0x4000082 thrsleep syz-fuzzer 15015 65727 37861 0 3 0x4000082 thrsleep syz-fuzzer 15015 474192 37861 0 3 0x4000082 thrsleep syz-fuzzer 15015 222570 37861 0 3 0x4000082 nanosleep syz-fuzzer 15015 380489 37861 0 3 0x4000082 thrsleep syz-fuzzer 37861 351925 87003 0 3 0x10008a pause ksh 87003 423511 24666 0 3 0x92 select sshd 7733 79882 1 0 3 0x100083 ttyin getty 24666 43384 1 0 3 0x80 select sshd 33214 47475 88165 73 2 0x100090 syslogd 88165 382504 1 0 3 0x100082 netio syslogd 93557 432490 1 77 3 0x100090 poll dhclient 85936 258849 1 0 3 0x80 poll dhclient 23714 194145 0 0 3 0x14200 pgzero zerothread 20597 127829 0 0 3 0x14200 aiodoned aiodoned 6966 57783 0 0 3 0x14200 syncer update 10455 21074 0 0 3 0x14200 cleaner cleaner 54169 331775 0 0 7 0x14200 reaper 50449 240460 0 0 3 0x14200 pgdaemon pagedaemon 29618 219893 0 0 3 0x14200 bored crynlk 3854 239743 0 0 3 0x14200 bored crypto 23950 87031 0 0 3 0x40014200 acpi0 acpi0 13574 371010 0 0 3 0x40014200 idle1 2599 183710 0 0 3 0x14200 bored softnet 86968 223158 0 0 3 0x14200 bored systqmp 89912 242491 0 0 3 0x14200 bored systq 55316 58426 0 0 3 0x40014200 bored softclock 50897 38587 0 0 3 0x40014200 idle0 19356 2807 0 0 3 0x14200 bored smr 1 263826 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 (0xffff800020b8c450) #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 9455 6319K 6321K 78643K 10802 0 0 pcb 23 9K 11K 78643K 1297 0 0 rtable 83 2K 3K 78643K 2466 0 0 ifaddr 30 10K 11K 78643K 349 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 120 0 0 iov 0 0K 32K 78643K 186 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 2652 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 34 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 177 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 4 9K 33K 78643K 2889 0 0 sigio 0 0K 0K 78643K 43 0 0 proc 41 38K 70K 78643K 2629 0 0 subproc 17 1K 2K 78643K 901 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 318 0 0 in_multi 22 1K 2K 78643K 679 0 0 ether_multi 1 0K 0K 78643K 14 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 986 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 89 12K 31K 78643K 10341 0 0 UVM aobj 105 3K 3K 78643K 121 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 132 0 0 NDP 4 0K 0K 78643K 162 0 0 temp 97 2733K 2803K 78643K 14918 0 0 kqueue 0 0K 0K 78643K 35 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 64 108 0 104 1 0 1 1 0 8 0 inpcbpl 280 1335 0 1328 1 0 1 1 0 8 0 plimitpl 152 239 0 232 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 606 0 573 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 12 0 12 1 1 0 1 0 8 0 tcpcb 544 482 0 478 1 0 1 1 0 8 0 nd6 48 159 0 156 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 2479 0 2331 15 3 12 13 0 8 1 art_table 32 2480 0 2331 2 0 2 2 0 8 0 art_node 16 605 0 575 1 0 1 1 0 8 0 sysvmsgpl 40 31 0 12 1 0 1 1 0 8 0 semapl 112 173 0 163 1 0 1 1 0 8 0 shmpl 112 119 0 16 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4462 0 3005 48 0 48 48 0 8 0 ffsino 272 4462 0 3005 98 0 98 98 0 8 0 nchpl 144 7923 0 6308 61 0 61 61 0 8 0 uvmvnodes 72 5372 0 0 98 0 98 98 0 8 0 vnodes 200 5372 0 0 283 0 283 283 0 8 0 namei 1024 30097 0 30097 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 20851 0 20851 18 17 1 6 0 8 1 sigapl 432 2907 0 2894 4 2 2 3 0 8 0 futexpl 56 22989 0 22989 2 1 1 1 0 8 1 knotepl 112 1634 0 1621 1 0 1 1 0 8 0 kqueuepl 104 572 0 570 1 0 1 1 0 8 0 pipepl 112 1890 0 1877 5 4 1 2 0 8 0 fdescpl 488 2908 0 2895 3 0 3 3 0 8 0 filepl 152 17048 0 16976 10 5 5 7 0 8 1 lockfpl 104 543 0 543 8 7 1 1 0 8 1 lockfspl 48 171 0 171 8 7 1 1 0 8 1 sessionpl 112 68 0 59 1 0 1 1 0 8 0 pgrppl 48 108 0 99 1 0 1 1 0 8 0 ucredpl 96 5194 0 5186 1 0 1 1 0 8 0 zombiepl 144 2895 0 2894 4 3 1 1 0 8 0 processpl 888 2924 0 2894 4 0 4 4 0 8 0 procpl 600 7493 0 7452 6 2 4 5 0 8 0 srpgc 64 312 0 312 9 8 1 1 0 8 1 sosppl 128 30 0 30 7 7 0 1 0 8 0 sockpl 384 2656 0 2639 6 3 3 4 0 8 1 mcl64k 65536 9 0 0 2 0 2 2 0 8 0 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 14 0 0 2 0 2 2 0 8 0 mcl9k 9216 12 0 0 1 0 1 1 0 8 0 mcl8k 8192 7 0 0 1 0 1 1 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 142 0 0 17 1 16 17 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 314 0 0 11 0 11 11 0 8 0 bufpl 256 10799 0 3794 438 0 438 438 0 8 0 anonpl 16 331243 0 326240 107 70 37 41 0 125 7 amapchunkpl 152 23093 0 22997 47 41 6 12 0 158 0 amappl16 192 13721 0 13416 121 98 23 28 0 8 7 amappl15 184 415 0 415 7 6 1 1 0 8 1 amappl14 176 774 0 769 2 1 1 1 0 8 0 amappl13 168 47 0 47 4 3 1 1 0 8 1 amappl12 160 611 0 608 1 0 1 1 0 8 0 amappl11 152 342 0 328 1 0 1 1 0 8 0 amappl10 144 732 0 730 2 1 1 1 0 8 0 amappl9 136 1573 0 1570 1 0 1 1 0 8 0 amappl8 128 1005 0 988 1 0 1 1 0 8 0 amappl7 120 745 0 736 1 0 1 1 0 8 0 amappl6 112 210 0 201 1 0 1 1 0 8 0 amappl5 104 958 0 948 1 0 1 1 0 8 0 amappl4 96 2326 0 2304 1 0 1 1 0 8 0 amappl3 88 1153 0 1142 1 0 1 1 0 8 0 amappl2 80 18536 0 18472 4 2 2 3 0 8 0 amappl1 72 86256 0 85828 24 14 10 19 0 8 0 amappl 80 8546 0 8509 2 0 2 2 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 64 120 0 16 2 0 2 2 0 8 0 uaddrrnd 24 2908 0 2894 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2908 0 2894 1 0 1 1 0 8 0 vmmpekpl 168 27430 0 27401 2 0 2 2 0 8 0 vmmpepl 168 330725 0 329427 169 94 75 81 0 357 13 vmsppl 360 2907 0 2894 2 0 2 2 0 8 0 pdppl 4096 5824 0 5788 6 0 6 6 0 8 1 pvpl 32 895746 0 887656 232 126 106 115 0 265 23 pmappl 232 2907 0 2894 7 6 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 600 0 8 17 0 17 17 0 8 0