panic: pmap_do_remove: unmanaged PTP detected

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 88dc91f4cc14 session_index was never actually implemented,..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=17502112580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1bc15e68cd2a49e5
dashboard link: https://syzkaller.appspot.com/bug?extid=107c0e5944d396e11242

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e77db671f1f9/disk-88dc91f4.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/4b027f3dc8b1/bsd-88dc91f4.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0cb0716dc11d/kernel-88dc91f4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+107c0e...@syzkaller.appspotmail.com

panic: pmap_do_remove: unmanaged PTP detected
Starting stack trace...
panic(ffffffff832fb07f) at panic+0x1ba sys/kern/subr_prf.c:229
pmap_do_remove(fffffd80662f2a30,110c230000,110e230000,0) at pmap_do_remove+0xd85 sys/arch/amd64/amd64/pmap.c:1846
uvm_unmap_kill_entry_withlock(fffffd806cac5e78,fffffd8063db1628,0) at uvm_unmap_kill_entry_withlock+0x269 sys/uvm/uvm_map.c:1863
uvm_map_teardown(fffffd806cac5e78) at uvm_map_teardown+0x117 uvm_map_addr_RBT_LEFT sys/uvm/uvm_map.h:-1 [inline]
uvm_map_teardown(fffffd806cac5e78) at uvm_map_teardown+0x117 sys/uvm/uvm_map.c:2486
exit1(ffff80003c93ad18,0,0,3) at exit1+0x6e6 sys/kern/kern_exit.c:259
proc_suspend_check_locked(ffff80003c93ad18,0) at proc_suspend_check_locked+0x45a sys/kern/kern_sig.c:2235
userret(ffff80003c93ad18) at userret+0x8c proc_suspend_check sys/kern/kern_sig.c:-1 [inline]
userret(ffff80003c93ad18) at userret+0x8c sys/kern/kern_sig.c:2194
syscall(ffff80002a8cb900) at syscall+0xa56 mi_syscall_return sys/sys/syscall_mi.h:203 [inline]
syscall(ffff80002a8cb900) at syscall+0xa56 sys/arch/amd64/amd64/trap.c:796
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7ca284418510, count: 248
End of stack trace.

syncing disks...set $lines = 0
set $maxwidth = 0
show panic
trace
show registers
show proc
ps
show all locks
show malloc
show all pools
machine ddbcpu 0
trace
machine ddbcpu 1
trace


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