Two dir's of identical ownership, but `cat > f` produces differently owned files

Question

Why do myfile.txt and myotherfile.txt have different ownership?

The first directory, myhandle on my Desktop, was created using sudo chown. The second directory under /run/... was created as a networked file system by keybase.

From my ~/Desktop/myhandle:

$ ls -l ..
total 0
drwx------ 1 me root 126 Nov 23 23:10 myhandle

$ ls -la
total 0
drwx------ 1 me root 126 Nov 23 23:10 .
dr-x------ 1 me root  46 Nov 20 01:50 ..

$ cat > myfile.txt
test

$ ls -la
total 4
drwx------ 1 me root 146 Nov 23 23:11 .
dr-x------ 1 me root  46 Nov 20 01:50 ..
-rw-rw-r-- 1 me me    5 Nov 23 23:11 myfile.txt

From /run/user/1000/keybase/kbfs/private/myhandle

$ ls -l ..
total 1
drwx------ 1 me root 504 Nov 23 23:12 myhandle

$ ls -la
total 0

$ cat > myotherfile.txt
test

$ ls -la
total 1
-rw------- 1 me root 5 Nov 23 23:12 myotherfile.txt

Answer 1

The path component kbfs sounds like its contents could be on another filesystem (kbfs is the name of the filesystem keybase uses).

It is not unheard-of for special file systems to not adhere to common expectations about permissions.

See also an old bug in keybase where, in its filesystem, it was reporting completely different permissions than it was actually using: https://github.com/keybase/kbfs/issues/212