So I was looking at the todo's placed on the bitbucket site. I figured I
would take on the FUSE stuff, since that interests me the most.

Outside of my first tought of grabbing PID from fuse_in_header and doing a
lookup which is mentioned in the wiki blurb on fuse.

Stephen thinks the problem here is that pid can torially wrap, causing the
fs to lookup the context of the wrong application. While possible, the
worst case scenario is that data gets released t the FUSE driver, but since
the original application requesting the data is dead for this occur, I dont
think it matters.

My second thought is, cant we just implement xattr support in the sdcard
userspace portion of the fuse filesystem and selinux.security getxattr
calls?

I was looking at the kernel code in selinux and looks like it just calls
the indode operation for getxattr, which should result with fuse forwarding
it to the userspace fs.

Then can't we just configure SELinux to use xattrs on fuse via:
fs_use_xattr fuse u:object_r:labeledfs:s0;

And lastly add the support to sdcardfs.

If these ideas doen't work out of the box (except the userspace portion),
the other options get gross quick considering that the security field in
the cred struct is an apaque pointer. We could replace the padding portion
of fuse_in_header which is a uint32_t with a 4 byte identifier and some
common method for lsms to populate it. This, a call to some generic method
would call an lsm specific handler to populate this field, for SELinux, it
could be the SID, but this seems awful.


-- 
Respectfully,

William C Roberts
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