Messages in this thread | | | Subject | Re: [PATCH] Filesystem linking protections | From | Lorenzo Hernández García-Hierro <> | Date | Mon, 07 Feb 2005 20:34:33 +0100 |
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El lun, 07-02-2005 a las 14:14 -0500, Valdis.Kletnieks@vt.edu escribió: > On Mon, 07 Feb 2005 19:57:06 +0100, Lorenzo =?ISO-8859-1?Q?Hern=E1ndez_?= =?ISO-8859-1?Q?Garc=EDa-Hierro?= said: > > > This patch adds two checks to do_follow_link() and sys_link(), for > > prevent users to follow (untrusted) symlinks owned by other users in > > world-writable +t directories (i.e. /tmp), unless the owner of the > > symlink is the owner of the directory, users will also not be able to > > hardlink to files they do not own. > > This should be done using the LSM framework. That's what it's *THERE* for. > I've previously posted an LSM that does these checks (and a few others), it > should be in the archives.
vSecurity also implements this and many other "ported" features from OpenWall and grSecurity.
But It's better to give users a "secure-by-default" status, at least on those parts that don't affect negatively the stability or the performance itself.
The LSM hook call is before the check, so, LSM framework still has the control over it, until it releases the operation giving control back to the standard function.
If users must rely on LSM or other external solutions for applying basic security checks (as the framework itself only provides the way to apply them, the checks need to be implemented in a module), then we are making them unable to be protected using the "default" configuration.
Cheers, -- Lorenzo Hernández García-Hierro <lorenzo@gnu.org> [1024D/6F2B2DEC] & [2048g/9AE91A22][http://tuxedo-es.org] [unhandled content-type:application/pgp-signature] | |