Re: Linux 2.4.27 SECURITY BUG - TCP Local and REMOTE(verified)Denial of Service Attack

From: Jurjen Oskam
Date: Mon Sep 13 2004 - 02:00:36 EST


On Sun, Sep 12, 2004 at 12:40:56PM -0600, Wolfpaw - Dale Corse wrote:

> the bug is application level in this case. Can you explain
> though, how it is appropriate to have no timeout on CLOSE_WAIT.

See TCP/IP Illustrated, Volume 1 by W. Richard Stevens (ISBN
0-201-63346-9), page 238: "TCP Half-Close".

In short, you don't have a timeout on CLOSE_WAIT for the same reason you
don't have a timeout on ESTABLISHED.

--
Jurjen Oskam
"I often reflect that if "privileges" had been called "responsibilities" or
"duties", I would have saved thousands of hours explaining to people why
they were only gonna get them over my dead body." - Lee K. Gleason, VMS sysadmin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/