oss-sec mailing list archives
Re: Small exposure in ocfs2 fast symlinks.
From: Joel Becker <Joel.Becker () oracle com>
Date: Fri, 1 Oct 2010 14:31:12 -0700
On Thu, Sep 30, 2010 at 10:32:14PM +0800, Eugene Teo wrote:
On 09/30/2010 01:49 PM, Joel Becker wrote:On Wed, Sep 29, 2010 at 08:30:09PM -0700, Greg KH wrote:On Wed, Sep 29, 2010 at 07:04:07PM -0700, Joel Becker wrote:Hey Everyone, We just discovered that ocfs2 could walk off the end of fast symlinks -- that is, symlinks that are stored directly in the inode block. ocfs2 terminates these with NUL characters, but a disk corruption or an attacker with direct access to the ocfs2 disk could overwrite the NUL. Following the symlink via the filesystem would walk off the end of the in-memory block buffer. We're not sure how exploitable this is, but I figured I'd provide a heads-up. The fix is in ocfs2's git tree and will be sent upstream tonight. Erratas with the fix are being built.Care to send the git commit id to the stable () kernel org tree when it hits Linus's tree so it gets backported there?I Cc'd stable () kernel org in the commit, don't worry ;-)Thanks, please also cc oss-sec when the commit hash is available.
The commit hash in Linus's tree is 1fc8a117865b54590acd773a55fbac9221b018f0. This problem only exists from 2.6.30 onwards; it is not present in older kernels. Joel -- "In the long run...we'll all be dead." -Unknown Joel Becker Consulting Software Developer Oracle E-mail: joel.becker () oracle com Phone: (650) 506-8127
Current thread:
- Re: Small exposure in ocfs2 fast symlinks. Joel Becker (Oct 01)
- <Possible follow-ups>
- Re: Small exposure in ocfs2 fast symlinks. Josh Bressers (Oct 04)