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Date: Tue, 14 Apr 2009 21:00:45 GMT
From: Ernest Hua <ehua@maxiscale.com>
To: freebsd-gnats-submit@FreeBSD.org
Subject: ip_id not protected ...
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>Number:         133736
>Category:       kern
>Synopsis:       [udp] ip_id not protected ...
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-net
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Apr 14 21:10:02 UTC 2009
>Closed-Date:    
>Last-Modified:  Tue Apr 14 21:39:35 UTC 2009
>Originator:     Ernest Hua
>Release:        7.0-RELEASE
>Organization:
MaxiScale, Inc.
>Environment:
FreeBSD r01s18 7.0-RELEASE FreeBSD 7.0-RELEASE #0: ... amd64

This is our own compiled kernel that is based on 7.0-RELEASE with the dump/snapshot patch applied.

>Description:
We have evidence of IP fragments from different UDP transactions being stamped with the same 16-bit id.

>How-To-Repeat:
Using a multi-threaded application, transmit lots of large (much greater than MTU) UDP packets of the same size with known but distinctive content to a single destination port using a multi-core system as the transmitter.

There will be occasional data corruption found at the destination where data from one transaction is found in the payload of another transaction.


>Fix:
ip_id needs some atomic protection.

The same can probably be said of the random id generator.


>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: freebsd-bugs->freebsd-net 
Responsible-Changed-By: linimon 
Responsible-Changed-When: Tue Apr 14 21:38:57 UTC 2009 
Responsible-Changed-Why:  
Over to maintainer(s). 

http://www.freebsd.org/cgi/query-pr.cgi?pr=133736 
>Unformatted:
