Re: Suid mount helpers fail to anticipate RLIMIT_FSIZE

["Dmitry V. Levin" <ldv () altlinux org>]

On Thu, Mar 03, 2011 at 09:42:17PM -0500, Dan Rosenberg wrote:
[...]
> I discovered that essentially every suid mount helper that uses
> addmntent() (or invokes util-linux mount, which in turn calls
> addmntent()) to add entries to /etc/mtab fails to anticipate a low
> value for RLIMIT_FSIZE, allowing unprivileged users to corrupt
> /etc/mtab and possibly manipulate mountpoint options.  Affected
> software includes at least:
[...]
> There are a few possible options

One more option is to replace /etc/mtab regular file with a symlink to
/proc/mounts, thus making any /etc/mtab editing unneeded.


-- 
ldv

Attachment: _bin
Description: