panic: pmap_remove_ptes: unmanaged page marked PG_PVLIST: va ADDR, opte 0x3efff (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 879ea5f6fdb7 Update to reflect support for special keys.
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=168b4612580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=5743a7a1158aaf9df698

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5cdfa60cfda3/disk-879ea5f6.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/446b64d9feca/bsd-879ea5f6.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7ba09c19069c/kernel-879ea5f6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5743a7...@syzkaller.appspotmail.com

panic: pmap_remove_ptes: unmanaged page marked PG_PVLIST: va 0x1b2d060000, opte 0x3efff
Starting stack trace...
panic(ffffffff8343936e) at panic+0x1d0 sys/kern/subr_prf.c:229
pmap_remove_pte(fffffd8073df5100,fffffd8008912218,7f800d968100,1b2d020000,1b2d200000,0) at pmap_remove_pte
pmap_do_remove(fffffd8073df5100,1b2d020000,1b2d420000,0) at pmap_do_remove+0x589 sys/arch/amd64/amd64/pmap.c:1920
uvm_unmap_kill_entry_withlock(fffffd806fa627a8,fffffd80710e5df8,0) at uvm_unmap_kill_entry_withlock+0x269 sys/uvm/uvm_map.c:1863
uvm_map_teardown(fffffd806fa627a8) at uvm_map_teardown+0x117 uvm_map_addr_RBT_LEFT sys/uvm/uvm_map.h:-1 [inline]
uvm_map_teardown(fffffd806fa627a8) at uvm_map_teardown+0x117 sys/uvm/uvm_map.c:2486
exit1(ffff80003c427780,0,0,1) at exit1+0x6fc sys/kern/kern_exit.c:260
sys_exit(ffff80003c427780,ffff80002a390f20,ffff80002a390e70) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a390f20) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a390f20) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x715a036e3380, count: 248
End of stack trace.


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