From: David Miller <davem@davemloft.net>
To: jdb@comx.dk
Cc: netdev@vger.kernel.org
Subject: Re: [RFC] [PATCH] Fix UDP short packet false positive
Date: Fri, 06 Feb 2009 01:08:24 -0800 (PST) [thread overview]
Message-ID: <20090206.010824.99072382.davem@davemloft.net> (raw)
In-Reply-To: <1233910824.21135.6.camel@localhost.localdomain>
From: Jesper Dangaard Brouer <jdb@comx.dk>
Date: Fri, 06 Feb 2009 10:00:24 +0100
> On Thu, 2009-02-05 at 15:06 -0800, David Miller wrote:
> > From: Jesper Dangaard Brouer <jdb@comx.dk>
> > Date: Thu, 05 Feb 2009 13:47:07 +0100
> >
> > > The UDP header pointer assignment must happen after calling
> > > pskb_may_pull(). As pskb_may_pull() can potentially alter the SKB
> > > buffer.
> >
> > Excellent work!
>
> Thanks :-)
>
> I'm wondering if the ip_hdr() pointer can be changed by the
> pskb_may_pull(), but I assume it cannot as it should already be in the
> linear area... right?
>
> Well the patch below, shows what I mean...
It has the same potential problem, but in this case you'd
only see corruption if the old skb->data buffer were reallocated
by another user and written into very quickly (or poison'd by
SLAB debugging).
Please respin this patch of your's with proper commit message
and signoffs, thanks!
BTW, ipv6 udp gets all of this right :-)
next prev parent reply other threads:[~2009-02-06 9:08 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-03 13:38 BUG: NIU driver: strange issues with multicast "UDP: short packet" Jesper Dangaard Brouer
2009-02-03 23:38 ` David Miller
2009-02-04 8:55 ` Jesper Dangaard Brouer
2009-02-04 9:00 ` David Miller
2009-02-04 9:32 ` Jesper Dangaard Brouer
2009-02-04 9:34 ` David Miller
2009-02-05 12:44 ` Jesper Dangaard Brouer
2009-02-05 12:47 ` [PATCH] Fix UDP short packet false positive Jesper Dangaard Brouer
2009-02-05 23:06 ` David Miller
2009-02-06 9:00 ` [RFC] " Jesper Dangaard Brouer
2009-02-06 9:08 ` David Miller [this message]
2009-02-06 9:55 ` [PATCH] udp: Fix potential wrong ip_hdr(skb) pointers Jesper Dangaard Brouer
2009-02-06 9:59 ` David Miller
2009-02-06 10:04 ` Eric Dumazet
2009-02-06 10:49 ` Jesper Dangaard Brouer
2009-02-06 11:11 ` David Miller
2009-02-04 11:52 ` BUG: NIU driver: strange issues with multicast "UDP: short packet" Herbert Xu
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