Re: [AppArmor 01/41] Pass struct vfsmount to the inode_create LSM hook

Kyle Moffett
2007-05-26T05:21:28Z

On May 24, 2007, at 14:58:41, Casey Schaufler wrote:
> On Fedora zcat, gzip and gunzip are all links to the same file. I
> can imagine (although it is a bit of a stretch) allowing a set of
> users access to gunzip but not gzip (or the other way around).

That is a COMPLETE straw-man argument. I can override your "check"
with this absolutely trivial perl code:

exec { "/usr/bin/gunzip" } "gzip", "-9", "some/file/to.gz";

Pathname-based checks are pretty fundamentally insecure. If you want
to protect a "name", then you should tag the "name" with security
attributes (IE: AppArmor). On the other hand, if you actually want
to protect the _data_, then tagging the _name_ is flawed; tag the
*DATA* instead.

Cheers,
Kyle Moffett