[lkml]   [2008]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 4/4] ext3: Avoid printk floods in the face of directory corruption
On Sat, Sep 13, 2008 at 11:32 PM, Theodore Ts'o <> wrote:
> Note: some people thinks this represents a security bug, since it
> might make the system go away while it is printing a large number of
> console messages, especially if a serial console is involved. Hence,
> it has been assigned CVE-2008-3528, but it requires that the attacker
> either has physical access to your machine to insert a USB disk with a
> corrupted filesystem image (at which point why not just hit the power
> button), or is otherwise able to convince the system administrator to
> mount an arbitrary filesystem image (at which point why not just
> include a setuid shell or world-writable hard disk device file or some
> such). Me, I think they're just being silly.

The description should explain what the problem is. And the last
sentence is a little ambiguous.

This is a user-triggerable DoS. The administrator who mounted the
filesystem image or partition might not know that the dir->i_size and
dir->i_blocks are corrupted. A remote user just need to perform either
a read or write operation to the mounted image or partition, and this
could trigger the problem, resulting in a denial of service.

Take note that another problem the test image shows is that, the
ext2/3 (and possibly ext4) filesystem does not honour the read-only
mode when the revision level is too high. That is, when
le32_to_cpu(es->s_rev_level) > EXT3_MAX_SUPP_REV. Eric replied me in a
private email that this is a different, and unrelated bug that will be

Thanks, Eugene

 \ /
  Last update: 2008-09-18 02:59    [W:0.075 / U:7.364 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site