witness: lock order reversal: 1st 0xffff800020b3b5a0 &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 __sanitizer_cov_trace_pc+0x7 sys/dev/kcov.c:86 #7 exit1+0x73f sys/kern/kern_exit.c:302 #8 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #9 userret+0x347 sys/kern/kern_sig.c:1907 #10 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #10 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #11 Xsyscall+0x128 Stopped at db_enter+0x18: 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+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(ffff800020b39c38) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800025032dd0) 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,ffff800020b3b590,0,ffff800020b3b4e0,ffff800020b3b590) at Xresume_lapic_ltimer+0x26 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x7 sys/dev/kcov.c:86 exit1(ffff800020b39c38,0,3) at exit1+0x73f sys/kern/kern_exit.c:302 single_thread_check(ffff800020b39c38,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b39c38) at userret+0x347 sys/kern/kern_sig.c:1907 syscall(ffff800025033100) at syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(ffff800025033100) at syscall+0x614 sys/arch/amd64/amd64/trap.c:596 Xsyscall(6,0,32006,57,431bde82d7b634db,2d) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffddcf0, count: -13 ddb{0}> show registers rdi 0x3 rsi 0xffffffff82243e20 __sancov_gen_cov_switch_values.122 rbp 0xffff800025032bd0 rbx 0x3 rdx 0xffffffff821abff0 cpu_info_full_primary+0x1ff0 rcx 0x3 rax 0xffffffff821abff0 cpu_info_full_primary+0x1ff0 r8 0xffffffff81da2df5 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xfc4fba0aa4221a65 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff82337100 w_lodata+0x48250 r15 0xffffffff82345ee0 w_lodata+0x57030 rip 0xffffffff819ca3d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800025032bc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=347159 stat=dead flags process=1018 proc=82000 pri=50, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b3b4e0 user=0xffff80002502e000, vmspace=0xfffffd806e8d9b48 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 63828 397872 77223 32767 3 0x90 nanosleep syz-executor.0 77223 140393 54039 0 3 0x82 wait syz-executor.0 10407 348844 59259 32767 3 0x90 nanosleep syz-executor.1 59259 15140 54039 0 3 0x82 wait syz-executor.1 91632 73085 0 0 3 0x14200 bored sosplice 54039 431910 7634 0 3 0x82 thrsleep syz-fuzzer 54039 110519 7634 0 3 0x4000082 nanosleep syz-fuzzer 54039 460928 7634 0 3 0x4000082 thrsleep syz-fuzzer 54039 312974 7634 0 3 0x4000082 thrsleep syz-fuzzer 54039 293723 7634 0 3 0x4000082 thrsleep syz-fuzzer 54039 213574 7634 0 3 0x4000082 kqread syz-fuzzer 54039 302196 7634 0 3 0x4000082 thrsleep syz-fuzzer 54039 89871 7634 0 3 0x4000082 thrsleep syz-fuzzer 54039 95215 7634 0 3 0x4000082 thrsleep syz-fuzzer 54039 432333 7634 0 3 0x4000082 thrsleep syz-fuzzer 7634 342039 92021 0 3 0x10008a pause ksh 92021 226375 22733 0 3 0x92 select sshd 26951 59097 1 0 3 0x100083 ttyin getty 22733 144920 1 0 3 0x80 select sshd 67872 284637 94141 73 7 0x100090 syslogd 94141 398188 1 0 3 0x100082 netio syslogd 74296 287377 1 77 3 0x100090 poll dhclient 75720 108150 1 0 3 0x80 poll dhclient 48129 124563 0 0 3 0x14200 pgzero zerothread 56160 190783 0 0 3 0x14200 aiodoned aiodoned 17523 199046 0 0 3 0x14200 syncer update 12736 39735 0 0 3 0x14200 cleaner cleaner 89603 309765 0 0 2 0x14200 reaper 67000 160930 0 0 3 0x14200 pgdaemon pagedaemon 84193 93908 0 0 3 0x14200 bored crynlk 42784 95756 0 0 3 0x14200 bored crypto 34606 72944 0 0 3 0x40014200 acpi0 acpi0 39920 262710 0 0 3 0x40014200 idle1 5631 473870 0 0 3 0x14200 bored softnet 82874 31268 0 0 3 0x14200 bored systqmp 94039 349004 0 0 3 0x14200 bored systq 62091 473079 0 0 3 0x40014200 bored softclock 38171 194897 0 0 3 0x40014200 idle0 54480 277188 0 0 3 0x14200 bored smr 1 265872 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive mutex &pr->ps_mtx r = 0 (0xffff800020b3b5a0) #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 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #5 userret+0x347 sys/kern/kern_sig.c:1907 #6 syscall+0x614 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] #6 syscall+0x614 sys/arch/amd64/amd64/trap.c:596 #7 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9460 6321K 6321K 78643K 10787 0 0 pcb 23 9K 11K 78643K 1033 0 0 rtable 105 3K 3K 78643K 2319 0 0 ifaddr 36 11K 11K 78643K 332 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 95 0 0 iov 0 0K 24K 78643K 128 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1209 76K 76K 78643K 2369 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 20 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 1K 1K 78643K 120 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 6 17K 33K 78643K 2288 0 0 sigio 0 0K 0K 78643K 24 0 0 proc 41 38K 70K 78643K 2400 0 0 subproc 34 2K 2K 78643K 850 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 246 0 0 in_multi 33 2K 2K 78643K 621 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 896 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 90 21K 30K 78643K 8394 0 0 UVM aobj 83 3K 3K 78643K 89 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 122 0 0 NDP 7 0K 0K 78643K 153 0 0 temp 121 2734K 2800K 78643K 13212 0 0 kqueue 0 0K 0K 78643K 28 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 102 0 96 1 0 1 1 0 8 0 inpcbpl 280 1079 0 1072 1 0 1 1 0 8 0 plimitpl 152 203 0 194 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 573 0 529 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 401 0 394 1 0 1 1 0 8 0 nd6 48 150 0 144 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 2350 0 2159 14 2 12 13 0 8 0 art_table 32 2351 0 2159 2 0 2 2 0 8 0 art_node 16 572 0 532 1 0 1 1 0 8 0 sysvmsgpl 40 22 0 15 1 0 1 1 0 8 0 semapl 112 117 0 107 1 0 1 1 0 8 0 shmpl 112 87 0 6 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3612 0 2167 47 0 47 47 0 8 0 ffsino 272 3612 0 2167 98 1 97 97 0 8 0 nchpl 144 6290 0 4671 61 0 61 61 0 8 0 uvmvnodes 72 4471 0 0 82 0 82 82 0 8 0 vnodes 200 4471 0 0 236 0 236 236 0 8 0 namei 1024 23854 0 23854 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 16858 0 16858 13 12 1 7 0 8 1 sigapl 432 2315 0 2300 7 4 3 3 0 8 1 futexpl 56 16228 0 16228 1 0 1 1 0 8 1 knotepl 112 1402 0 1383 1 0 1 1 0 8 0 kqueuepl 104 437 0 435 1 0 1 1 0 8 0 pipepl 112 1686 0 1667 7 6 1 2 0 8 0 fdescpl 488 2316 0 2301 3 0 3 3 0 8 1 filepl 152 13149 0 13053 11 6 5 7 0 8 1 lockfpl 104 372 0 372 4 3 1 1 0 8 1 lockfspl 48 124 0 124 4 3 1 1 0 8 1 sessionpl 112 65 0 55 1 0 1 1 0 8 0 pgrppl 48 85 0 75 1 0 1 1 0 8 0 ucredpl 96 3535 0 3526 1 0 1 1 0 8 0 zombiepl 144 2301 0 2299 2 1 1 1 0 8 0 processpl 888 2332 0 2299 4 0 4 4 0 8 0 procpl 600 5698 0 5655 5 1 4 5 0 8 0 srpgc 64 288 0 288 5 4 1 1 0 8 1 sosppl 128 48 0 48 9 8 1 1 0 8 1 sockpl 384 2128 0 2111 5 2 3 4 0 8 1 mcl64k 65536 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 11 0 0 2 0 2 2 0 8 0 mcl9k 9216 13 0 0 1 0 1 1 0 8 0 mcl8k 8192 10 0 0 2 0 2 2 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 132 0 0 16 0 16 16 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 283 0 0 12 0 12 12 0 8 0 bufpl 256 8311 0 1306 438 0 438 438 0 8 0 anonpl 16 224505 0 219210 68 35 33 41 0 125 7 amapchunkpl 152 19519 0 19436 45 36 9 18 0 158 5 amappl16 192 8232 0 7922 55 37 18 28 0 8 2 amappl15 184 179 0 177 6 5 1 1 0 8 0 amappl14 176 678 0 670 2 1 1 1 0 8 0 amappl13 168 436 0 434 4 3 1 1 0 8 0 amappl12 160 268 0 267 1 0 1 1 0 8 0 amappl11 152 239 0 225 1 0 1 1 0 8 0 amappl10 144 567 0 565 2 1 1 1 0 8 0 amappl9 136 1308 0 1303 1 0 1 1 0 8 0 amappl8 128 741 0 722 1 0 1 1 0 8 0 amappl7 120 588 0 579 1 0 1 1 0 8 0 amappl6 112 146 0 135 1 0 1 1 0 8 0 amappl5 104 641 0 631 1 0 1 1 0 8 0 amappl4 96 2247 0 2217 1 0 1 1 0 8 0 amappl3 88 729 0 717 1 0 1 1 0 8 0 amappl2 80 14129 0 14059 4 2 2 3 0 8 0 amappl1 72 71634 0 71199 23 13 10 19 0 8 0 amappl 80 6689 0 6655 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 88 0 6 2 0 2 2 0 8 0 uaddrrnd 24 2316 0 2300 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2316 0 2300 1 0 1 1 0 8 0 vmmpekpl 168 23432 0 23405 2 0 2 2 0 8 0 vmmpepl 168 264517 0 263123 115 46 69 76 0 357 3 vmsppl 360 2315 0 2300 2 0 2 2 0 8 0 pdppl 4096 4640 0 4600 6 0 6 6 0 8 0 pvpl 32 679167 0 670659 182 80 102 112 0 265 23 pmappl 232 2315 0 2300 6 4 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 597 0 6 17 0 17 17 0 8 0