lkml.org 
[lkml]   [2006]   [Aug]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH] getsockopt() early argument sanity checking
Date
On Sunday 20 August 2006 01:05, Solar Designer wrote:
> I propose the attached patch (extracted from 2.4.33-ow1) for inclusion
> into 2.4.34-pre.
>
> (2.6 kernels could benefit from the same change, too, but at the moment
> I am dealing with proper submission of generic changes like this that
> are a part of 2.4.33-ow1.)

In general I don't think it makes sense to submit stuff for 2.4
that isn't in 2.6.

>
> The patch makes getsockopt(2) sanity-check the value pointed to by
> the optlen argument early on. This is a security hardening measure
> intended to prevent exploitation of certain potential vulnerabilities in
> socket type specific getsockopt() code on UP systems.

It's not only insufficient on SMP, but even on UP where a thread
can sleep in get_user and another one can run in this time.

Doing a check that is inherently racy everywhere doesn't seem like
a security improvement to me. If there is really a length checking bug somewhere
it needs to be fixed in a race-free way. If not then there is no need
for a change.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-08-20 10:37    [W:0.091 / U:6.608 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site