login: witness: thread 0xffff800020b92978 exiting with the following locks held: exclusive rrwlock inode r = 0 (0xfffffd806ec454e8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 panic: thread 0xffff800020b92978 cannot exit while holding sleeplocks Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *483528 34281 0 0x14000 0x200 1 reaper db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_thread_exit(9200e5ac2565c116) at witness_thread_exit+0x244 sys/kern/subr_witness.c:1377 reaper(0) at reaper+0x14f sys/kern/kern_exit.c:412 end trace frame: 0x0, count: 11 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb{1}> ddb{1}> set $lines = 0 ddb{1}> show panic thread 0xffff800020b92978 cannot exit while holding sleeplocks ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_thread_exit(9200e5ac2565c116) at witness_thread_exit+0x244 sys/kern/subr_witness.c:1377 reaper(0) at reaper+0x14f sys/kern/kern_exit.c:412 end trace frame: 0x0, count: -4 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b67ba0 rbx 0xffff800020b67c40 rdx 0xffffffff81f2fa3a apollo_pio_rec+0x9e58 rcx 0x201 rax 0x1 r8 0xffffffff8134b1f4 kprintf+0x174 r9 0x1 r10 0x2ac754159364e139 r11 0x644ab7bbec098efa r12 0x3000000008 r13 0xffff800020b67bb0 r14 0x100 r15 0x1 rip 0xffffffff8176ba08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b67b90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (reaper) pid=483528 stat=onproc flags process=14000 proc=200 pri=4, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020b21068,0xffff800020b21780 process=0xffff800020b5ad28 user=0xffff800020b62000, vmspace=0xffffffff82312540 estcpu=0, cpticks=2, pctcpu=0.4 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 93433 516483 88421 0 3 0x82 nanosleep syz-executor0 88421 470629 71914 0 3 0x82 thrsleep syz-execprog 88421 11004 71914 0 3 0x4000082 thrsleep syz-execprog 88421 111971 71914 0 3 0x4000082 thrsleep syz-execprog 88421 83892 71914 0 3 0x4000082 thrsleep syz-execprog 88421 192620 71914 0 3 0x4000082 thrsleep syz-execprog 88421 490517 71914 0 3 0x4000082 kqread syz-execprog 88421 315196 71914 0 3 0x4000082 thrsleep syz-execprog 88421 404657 71914 0 3 0x4000082 thrsleep syz-execprog 88421 77475 71914 0 3 0x4000082 thrsleep syz-execprog 71914 41092 5938 0 3 0x10008a pause ksh 5938 64426 51123 0 3 0x92 select sshd 80837 69898 1 0 3 0x100083 ttyin getty 51123 177319 1 0 3 0x80 select sshd 97376 24185 22786 73 3 0x100010 ffs_fsync syslogd 22786 321720 1 0 3 0x100082 netio syslogd 34256 190793 1 77 3 0x100090 poll dhclient 57951 25918 1 0 3 0x80 poll dhclient 23854 442382 0 0 3 0x14200 pgzero zerothread 90215 156484 0 0 3 0x14200 aiodoned aiodoned 36321 505121 0 0 3 0x14200 syncer update 93656 160336 0 0 3 0x14200 cleaner cleaner *34281 483528 0 0 7 0x14200 reaper 83870 366557 0 0 3 0x14200 pgdaemon pagedaemon 59833 131108 0 0 3 0x14200 bored crynlk 21821 365310 0 0 3 0x14200 bored crypto 20112 232209 0 0 3 0x40014200 acpi0 acpi0 69030 236708 0 0 3 0x40014200 idle1 58261 42999 0 0 3 0x14200 bored softnet 70835 224039 0 0 3 0x14200 bored systqmp 55940 65865 0 0 3 0x14200 bored systq 64798 383778 0 0 3 0x40014200 bored softclock 92538 460667 0 0 7 0x40014200 idle0 1 92605 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}>