panic: kmmaplk rwlock 0xffffffff83a2d660: enter read deadlock Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8342a7a3) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffffffff83a2d660,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 uvmfault_lookup(ffff80002a884910,0) at uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1880 uvm_fault_check(ffff80002a884910,ffff80002a884948,ffff80002a884980,0) at uvm_fault_check+0x4f sys/uvm/uvm_fault.c:693 uvm_fault(ffffffff83a2d578,ffff800029ee6000,0,2) at uvm_fault+0xe6 sys/uvm/uvm_fault.c:627 kpageflttrap(ffff80002a884ab0,ffff800029ee6000) at kpageflttrap+0x2d1 sys/arch/amd64/amd64/trap.c:-1 kerntrap(ffff80002a884ab0) at kerntrap+0x18a sys/arch/amd64/amd64/trap.c:528 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b kcov_remote_enter(0,ffff8000324c0018) at kcov_remote_enter+0x122 sys/dev/kcov.c:670 timeout_run(ffffffff8389bd30,ffff8000380d32e8) at timeout_run+0xdf sys/kern/kern_timeout.c:696 softclock_process_tick_timeout(ffff8000380d32e8,0) at softclock_process_tick_timeout+0x230 sys/kern/kern_timeout.c:756 softclock(0) at softclock+0x152 sys/kern/kern_timeout.c:788 softintr_dispatch(0) at softintr_dispatch+0xf9 sys/kern/kern_softintr.c:87 end trace frame: 0xffff80002a884d00, count: 0 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: kmmaplk rwlock 0xffffffff83a2d660: enter read deadlock ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8342a7a3) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffffffff83a2d660,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 uvmfault_lookup(ffff80002a884910,0) at uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1880 uvm_fault_check(ffff80002a884910,ffff80002a884948,ffff80002a884980,0) at uvm_fault_check+0x4f sys/uvm/uvm_fault.c:693 uvm_fault(ffffffff83a2d578,ffff800029ee6000,0,2) at uvm_fault+0xe6 sys/uvm/uvm_fault.c:627 kpageflttrap(ffff80002a884ab0,ffff800029ee6000) at kpageflttrap+0x2d1 sys/arch/amd64/amd64/trap.c:-1 kerntrap(ffff80002a884ab0) at kerntrap+0x18a sys/arch/amd64/amd64/trap.c:528 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b kcov_remote_enter(0,ffff8000324c0018) at kcov_remote_enter+0x122 sys/dev/kcov.c:670 timeout_run(ffffffff8389bd30,ffff8000380d32e8) at timeout_run+0xdf sys/kern/kern_timeout.c:696 softclock_process_tick_timeout(ffff8000380d32e8,0) at softclock_process_tick_timeout+0x230 sys/kern/kern_timeout.c:756 softclock(0) at softclock+0x152 sys/kern/kern_timeout.c:788 softintr_dispatch(0) at softintr_dispatch+0xf9 sys/kern/kern_softintr.c:87 dosoftint(0) at dosoftint+0x48 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 pmap_tlb_shootrange(0,ffff80003a0d6000,ffff80003a4d6000,1) at pmap_tlb_shootrange+0xe9 sys/arch/amd64/amd64/pmap.c:3368 pmap_do_remove(ffffffff839c8250,ffff80003a0d6000,ffff80003a4d6000,0) at pmap_do_remove+0x6d2 sys/arch/amd64/amd64/pmap.c:1938 uvm_unmap_kill_entry_withlock(ffffffff83a2d578,fffff90069397358,1) at uvm_unmap_kill_entry_withlock+0x269 sys/uvm/uvm_map.c:1869 uvm_unmap_remove(ffffffff83a2d578,ffff80003a0d6000,ffff80003a4d6000,ffff80002a885018,0,1,bf40289b93cdd884) at uvm_unmap_remove+0x6c2 sys/uvm/uvm_map.c:2008 uvm_unmap(ffffffff83a2d578,ffff80003a0d6000,ffff80003a4d6000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline] uvm_unmap(ffffffff83a2d578,ffff80003a0d6000,ffff80003a4d6000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1799 km_free(ffff80003a0d6000,400000,ffffffff836393e0,ffffffff836394c8) at km_free+0x85 sys/uvm/uvm_km.c:714 kd_free(ffff8000015ec280) at kd_free+0x84 sys/dev/kcov.c:564 kcovclose(3f1300,3,2000,ffff80002a736d00) at kcovclose+0xe4 sys/dev/kcov.c:-1 spec_close(ffff80002a8851f0) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffff9006caba8c8,3,fffff90007ffd680,ffff80002a736d00) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffff9006cc39620,ffff80002a736d00) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffff9006cc39620,ffff80002a736d00) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(fffff9006cc39620,ffff80002a736d00) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffff9006cc39620,ffff80002a736d00) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80002a736d00) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80002a736d00,43,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a736d00,ffff80002a885550,ffff80002a8854a0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a885550) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a885550) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7a91de41c790, count: -34 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a884610 rbx 0xffff800029ee6000 rdx 0 rcx 0 rax 0xffff80002a736d00 r8 0x101010101010101 r9 0x8080808080808080 r10 0x70e5d555d5898ddd r11 0x46630f1cf5751fde r12 0 r13 0xffff80002a736d04 r14 0 r15 0x1 rip 0xffffffff8169c655 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a884600 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=301058 pid=72525 tcnt=0 stat=onproc flags process=a proc=2000 runpri=17, usrpri=50, slppri=17, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=1 forw=0xffffffffffffffff, list=0xffff80002a7362a0,0xffff80002a7367e0 process=0xffff80002a79f190 user=0xffff80002a880000, vmspace=0xfffff90073263178 estcpu=36, cpticks=15, pctcpu=0.1, user=0, sys=0, intr=1 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 55775 282761 56168 0 2 0 syz-executor 55775 492345 56168 0 3 0x4000080 fsleep syz-executor 30130 131268 20171 0 2 0 syz-executor 30130 94977 20171 0 3 0x4000080 fsleep syz-executor 33387 416731 28250 0 2 0 syz-executor 33387 257480 28250 0 2 0x4000000 syz-executor 60350 253653 46659 0 3 0x80 nanoslp syz-executor 60350 488758 46659 0 3 0x4000088 kqsel syz-executor 60350 202986 46659 0 3 0x4000080 fsleep syz-executor 79954 330931 38323 -1 3 0x90 nanoslp syz-executor 79954 142035 38323 -1 3 0x4000090 kqpoll syz-executor 79954 340395 38323 -1 3 0x4000090 kqpoll syz-executor 79954 25658 38323 -1 3 0x4000090 fsleep syz-executor 48930 28006 23762 0 3 0x80 nanoslp syz-executor 48930 313346 23762 0 3 0x4000080 lockf syz-executor 48930 439754 23762 0 3 0x4000080 fsleep syz-executor 48930 277653 23762 0 3 0x4000080 fsleep syz-executor 45122 428886 55746 0 3 0x80 nanoslp syz-executor 45122 516938 55746 0 3 0x4000080 kqsel syz-executor 45122 314388 55746 0 3 0x4000080 fsleep syz-executor 35855 427471 1 0 3 0x100083 ttyin getty 56168 215582 28582 0 3 0x82 nanoslp syz-executor 68501 347273 0 0 3 0x14280