From: vesseur@fwi.uva.nl (Joep JJ Vesseur) Subject: Re: clearing SUID bit on writes Date: 1 Sep 1992 23:50:18 GMT
Frank T Lofaro <fl0p+@andrew.cmu.edu> writes:
> Linux should definitely un-setuid and un-setgid files on any
>modification (such as an append). Otherwise it could prove to be a very
>nasty security hole.
>[...] doesn't belong in a secure (well,
>as secure as UN*X can reasonably be) environment.
well, i don't know to what extend linux _is_ secure (anyone out there
cares to make any correctness proofs?) and whether anyone uses it
as a real multiple user (read: different users) system at the moment,
but no doubt this will happen in the future.
i only don't think it should clean the bit on all modifications, only
those initiated by users with a different real-uid than the owner of
the file, in contrast to sysV.
joep.