lkml.org 
[lkml]   [2010]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v1.2 0/5] IMA: making i_readcount a first class inode citizen (reposting)
On Sun, Nov 21, 2010 at 5:18 AM, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
>
> IMA (and the proposed EVM/IMA-appraisal patches) detects file change
> based on i_version. When the file is closed, if the file has changed,
> IMA marks the file as needing to be re-measured. Of course this requires
> the filesystem to be mounted with iversion. Don't know if this helps.

If you only do this at close time, I see a _major_ security hole.

The attacker can just write to the file, and keep it open. Ta-daa,
everybody who reads it sees the new contents, but your IMA logic is
oblivious and thinks it doesn't need to be re-measured.

Linus


\
 
 \ /
  Last update: 2010-11-21 18:59    [W:0.049 / U:3.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site