Qà8Qà8witness: lock order reversal: 1st 0xffff800020b8ceb8 &pr->ps_mtx (&pr->ps_mtx) 2nd 0xffffffff82384c80 &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 witness_unlock+0x2b sys/kern/subr_witness.c:1260 #7 mtx_leave+0x97 sys/kern/kern_lock.c:360 #8 sched_exit+0x112 sys/kern/kern_sched.c:225 #9 exit1+0x8bf sys/kern/kern_exit.c:349 #10 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #11 userret+0x347 sys/kern/kern_sig.c:1907 #12 intr_user_exit+0x3c 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(ffffffff82384c80,9,0) at witness_checkorder+0xffc witness_debugger sys/kern/subr_witness.c:2504 [inline] witness_checkorder(ffffffff82384c80,9,0) at witness_checkorder+0xffc sys/kern/subr_witness.c:1084 __mp_lock(ffffffff82384a78) at __mp_lock+0xa1 schedclock(ffff800020b9a270) at schedclock+0x99 sys/kern/sched_bsd.c:547 hardclock(ffff800023e51230) 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,ffffffff821baff0,0,0,ffff800020b8cea8) at Xresume_lapic_ltimer+0x26 witness_unlock(ffff800020b8ceb8,8) at witness_unlock+0x2b sys/kern/subr_witness.c:1260 mtx_leave(ffff800020b8cea8) at mtx_leave+0x97 sys/kern/kern_lock.c:360 sched_exit(ffff800020b9a270) at sched_exit+0x112 sys/kern/kern_sched.c:225 exit1(ffff800020b9a270,0,3) at exit1+0x8bf sys/kern/kern_exit.c:349 single_thread_check(ffff800020b9a270,0) at single_thread_check+0x144 sys/kern/kern_sig.c:1938 userret(ffff800020b9a270) at userret+0x347 sys/kern/kern_sig.c:1907 intr_user_exit(0,0,cc,0,e11e80d80e0,e11e80d80d8) at intr_user_exit+0x3c end of kernel end trace frame: 0xe14b79ac7a0, count: -14 ddb{0}> show registers rdi 0x3 rsi 0xffffffff821fc9e0 __sancov_gen_cov_switch_values.122 rbp 0xffff800023e51030 rbx 0x3 rdx 0xffffffff821baff0 cpu_info_full_primary+0x1ff0 rcx 0x3 rax 0xffffffff821baff0 cpu_info_full_primary+0x1ff0 r8 0xffffffff818c8c95 witness_checkorder+0xfd5 r9 0x5 r10 0x3 r11 0xdb8a79de35ff4d09 r12 0xfffffd8002661340 r13 0xc r14 0xffffffff823357b0 w_lodata+0x4a560 r15 0xffffffff823423e0 w_lodata+0x57190 rip 0xffffffff81a42468 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023e51020 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=363783 stat=dead flags process=1000 proc=4082000 pri=80, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffffffffffffffff,0xffffffffffffffff process=0xffff800020b8cdf8 user=0xffff800023e4c000, vmspace=0xfffffd807effd168 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 3420 373892 17533 0 3 0x3000 suspend syz-executor.1 3420 143480 17533 0 7 0x4081000 syz-executor.1 25072 308993 0 0 3 0x14200 bored sosplice 17533 315498 49814 0 3 0x82 nanosleep syz-executor.1 97262 330731 49814 0 3 0x2 biowait syz-executor.0 49814 184787 85718 0 3 0x82 thrsleep syz-fuzzer 49814 137912 85718 0 3 0x4000082 nanosleep syz-fuzzer 49814 51713 85718 0 3 0x4000082 thrsleep syz-fuzzer 49814 317823 85718 0 3 0x4000082 thrsleep syz-fuzzer 49814 106269 85718 0 3 0x4000082 thrsleep syz-fuzzer 49814 243153 85718 0 3 0x4000082 thrsleep syz-fuzzer 49814 332948 85718 0 3 0x4000082 thrsleep syz-fuzzer 49814 326578 85718 0 3 0x4000082 thrsleep syz-fuzzer 49814 178768 85718 0 3 0x4000082 kqread syz-fuzzer 49814 499243 85718 0 3 0x4000082 thrsleep syz-fuzzer 85718 20341 55483 0 3 0x10008a pause ksh 55483 136507 46706 0 3 0x92 select sshd 13474 521972 1 0 3 0x100083 ttyin getty 46706 58547 1 0 3 0x80 select sshd 76069 84610 57231 74 3 0x100092 bpf pflogd 57231 316703 1 0 3 0x80 netio pflogd 97843 240853 62680 73 2 0x100090 syslogd 62680 368212 1 0 3 0x100082 netio syslogd 43857 500009 1 77 3 0x100090 poll dhclient 42792 193538 1 0 3 0x80 poll dhclient 52835 236581 0 0 3 0x14200 pgzero zerothread 19786 279564 0 0 3 0x14200 aiodoned aiodoned 55213 262654 0 0 3 0x14200 syncer update 55497 312687 0 0 3 0x14200 cleaner cleaner 76698 329902 0 0 3 0x14200 reaper reaper 8237 522763 0 0 3 0x14200 pgdaemon pagedaemon 16858 273428 0 0 3 0x14200 bored crynlk 74593 241799 0 0 3 0x14200 bored crypto 19044 316135 0 0 3 0x40014200 acpi0 acpi0 79718 251169 0 0 3 0x40014200 idle1 45359 242796 0 0 3 0x14200 bored softnet 20734 25776 0 0 3 0x14200 bored systqmp 64718 470412 0 0 3 0x14200 bored systq 60447 494103 0 0 3 0x40014200 bored softclock 35990 95089 0 0 3 0x40014200 idle0 72696 442560 0 0 3 0x14200 bored smr 1 481832 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 (0xffff800020b8ceb8) #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 sched_exit+0xa5 sys/kern/kern_sched.c:224 #4 exit1+0x8bf sys/kern/kern_exit.c:349 #5 single_thread_check+0x144 sys/kern/kern_sig.c:1938 #6 userret+0x347 sys/kern/kern_sig.c:1907 #7 intr_user_exit+0x3c Process 97262 (syz-executor.0) thread 0xffff800020b14008 (330731) exclusive rrwlock inode r = 0 (0xfffffd807ecbbb48) #0 witness_lock+0x52e sys/kern/subr_witness.c:1161 #1 rw_enter+0x46d sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 ufs_ihashins+0x45 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x133 sys/ufs/ffs/ffs_vfsops.c:1352 #5 ffs_inode_alloc+0x1cf sys/ufs/ffs/ffs_alloc.c:392 #6 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1164 #7 VOP_MKDIR+0x6a sys/kern/vfs_vops.c:449 #8 domkdirat+0x121 sys/kern/vfs_syscalls.c:2974 #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 exclusive rrwlock inode r = 0 (0xfffffd8069a224e0) #0 witness_lock+0x52e sys/kern/subr_witness.c:1161 #1 rw_enter+0x46d sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:602 #4 vn_lock+0x6e sys/kern/vfs_vnops.c:549 #5 vfs_lookup+0xe9 sys/kern/vfs_lookup.c:422 #6 namei+0x61c sys/kern/vfs_lookup.c:252 #7 domkdirat+0x75 sys/kern/vfs_syscalls.c:2959 #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 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9510 6537K 6923K 78643K 11943 0 0 pcb 25 9K 10K 78643K 351 0 0 rtable 113 4K 5K 78643K 356 0 0 ifaddr 54 12K 13K 78643K 119 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1492 0 0 iov 0 0K 28K 78643K 56 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1213 76K 77K 78643K 1776 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 37 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 5 13K 25K 78643K 815 0 0 sigio 0 0K 0K 78643K 2 0 0 proc 54 51K 71K 78643K 462 0 0 subproc 32 2K 2K 78643K 34 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 89 0 0 in_multi 33 2K 2K 78643K 62 0 0 ether_multi 1 0K 0K 78643K 8 0 0 mrt 0 0K 0K 78643K 4 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 254 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 20K 21K 78643K 3519 0 0 UVM aobj 23 2K 2K 78643K 30 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 26 0 0 NDP 10 0K 0K 78643K 30 0 0 temp 159 2735K 2803K 78643K 5587 0 0 kqueue 0 0K 0K 78643K 4 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 6 0 0 1 0 1 1 0 8 0 inpcbpl 280 367 0 360 1 0 1 1 0 8 0 plimitpl 152 42 0 34 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 53 0 9 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 140 0 136 1 0 1 1 0 8 0 rttmr 72 2 0 2 2 2 0 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 ppxss 1128 15 0 15 2 1 1 1 0 8 1 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 18 0 6 1 0 1 1 0 8 0 pfstkey 112 18 0 6 1 0 1 1 0 8 0 pfstate 328 18 0 6 2 0 2 2 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 188 0 0 12 0 12 12 0 8 0 art_table 32 189 0 0 2 0 2 2 0 8 0 art_node 16 46 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 0 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 35 0 25 1 0 1 1 0 8 0 shmpl 112 28 0 7 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2673 0 1247 47 0 47 47 0 8 0 ffsino 272 2673 0 1247 96 0 96 96 0 8 0 nchpl 144 3953 0 2315 61 0 61 61 0 8 0 uvmvnodes 72 3034 0 0 56 0 56 56 0 8 0 vnodes 200 3034 0 0 160 0 160 160 0 8 0 namei 1024 11180 0 11179 2 1 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 3 0 3 2 1 1 1 0 8 1 scxspl 192 10387 0 10386 9 8 1 6 0 8 0 sigapl 432 1015 0 1000 3 1 2 3 0 8 0 futexpl 56 8590 0 8590 1 0 1 1 0 8 1 knotepl 112 187 0 168 1 0 1 1 0 8 0 kqueuepl 104 154 0 152 1 0 1 1 0 8 0 pipepl 112 578 0 559 4 2 2 2 0 8 1 fdescpl 488 1016 0 1000 3 0 3 3 0 8 0 filepl 152 5295 0 5196 6 1 5 6 0 8 1 lockfpl 104 196 0 196 2 1 1 1 0 8 1 lockfspl 48 72 0 72 2 1 1 1 0 8 1 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 36 0 25 1 0 1 1 0 8 0 ucredpl 96 1256 0 1247 1 0 1 1 0 8 0 zombiepl 144 1001 0 1000 2 1 1 1 0 8 0 processpl 888 1032 0 1000 4 0 4 4 0 8 0 procpl 600 2755 0 2712 4 0 4 4 0 8 0 srpgc 64 2 0 2 2 2 0 1 0 8 0 sosppl 128 19 0 19 3 2 1 1 0 8 1 sockpl 384 667 0 648 3 0 3 3 0 8 1 mcl64k 65536 9 0 0 2 0 2 2 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 10 0 0 1 0 1 1 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 8 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 127 0 0 15 0 15 15 0 8 0 mtagpl 80 2 0 0 1 0 1 1 0 8 0 mbufpl 256 177 0 0 11 0 11 11 0 8 0 bufpl 256 6928 0 1188 359 0 359 359 0 8 0 anonpl 16 83410 0 73414 46 5 41 43 0 125 0 amapchunkpl 152 5272 0 5177 6 1 5 6 0 158 0 amappl16 192 4048 0 3512 29 1 28 29 0 8 0 amappl14 176 46 0 41 2 1 1 1 0 8 0 amappl13 168 372 0 371 1 0 1 1 0 8 0 amappl12 160 8 0 7 1 0 1 1 0 8 0 amappl11 152 60 0 42 1 0 1 1 0 8 0 amappl10 144 70 0 68 1 0 1 1 0 8 0 amappl9 136 1005 0 999 1 0 1 1 0 8 0 amappl8 128 556 0 538 1 0 1 1 0 8 0 amappl7 120 36 0 32 1 0 1 1 0 8 0 amappl6 112 56 0 49 1 0 1 1 0 8 0 amappl5 104 127 0 109 1 0 1 1 0 8 0 amappl4 96 1185 0 1157 1 0 1 1 0 8 0 amappl3 88 210 0 200 1 0 1 1 0 8 0 amappl2 80 7208 0 7137 4 2 2 3 0 8 0 amappl1 72 31459 0 31024 25 15 10 19 0 8 0 amappl 80 3004 0 2967 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 29 0 7 1 0 1 1 0 8 0 uaddrrnd 24 1016 0 1000 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1016 0 1000 1 0 1 1 0 8 0 vmmpekpl 168 11908 0 11877 2 0 2 2 0 8 0 vmmpepl 168 112965 0 111384 99 25 74 82 0 357 5 vmsppl 360 1015 0 1000 2 0 2 2 0 8 0 pdppl 4096 2040 0 2000 6 0 6 6 0 8 0 pvpl 32 282170 0 268991 121 9 112 116 0 265 4 pmappl 232 1015 0 1000 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 515 0 4 15 0 15 15 0 8 0