From: Marek Lindner <lindner_marek@yahoo.de>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: Re: [B.A.T.M.A.N.] [PATCH 2/3] batman-adv: Receive fragmented packets and merge
Date: Wed, 24 Apr 2013 03:43:06 +0800 [thread overview]
Message-ID: <201304240343.06405.lindner_marek@yahoo.de> (raw)
In-Reply-To: <20130423193004.GA16603@ritirata.org>
On Wednesday, April 24, 2013 03:30:04 Antonio Quartulli wrote:
> On Wed, Apr 24, 2013 at 03:17:26AM +0800, Marek Lindner wrote:
> > On Sunday, April 21, 2013 00:17:33 Martin Hundebøll wrote:
> > > + /* Make room for the rest of the fragments. */
> > > + if (pskb_expand_head(skb_out, 0, size - skb->len, GFP_ATOMIC) < 0) {
> > > + kfree_skb(skb_out);
> > > + goto free;
> > > + }
> >
> > If pskb_expand_head() really fails this function will lead to a crash
> > because skb_out points to undefined memory.
>
> I'm not sure about this. pskb_expand_head() can only fail in the early
> phase and in that case it seems to return the original skb as it was.
I guess I did not make myself sufficiently clear: If pskb_expand_head() fails
the skb is free'd with "kfree_skb(skb_out);" followed by a jump to "free"
where the recently free'd buffer is returned ...
> > Btw, is pskb_expand_head() enough to handle all cases ? Did you try this
> > with a large (4000 bytes or more) packet ?
>
> I don't personally see any problem with this. But maybe I am overlooking
> something..however, proper testing will make everybody happy :P
Agreed. I wasn't sure there is a problem but wanted to know whether it was
tested.
Cheers,
Marek
next prev parent reply other threads:[~2013-04-23 19:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-20 16:17 [B.A.T.M.A.N.] [PATCH 0/3] Fragmentation version 2 Martin Hundebøll
2013-04-20 16:17 ` [B.A.T.M.A.N.] [PATCH 1/3] batman-adv: Remove old fragmentation code Martin Hundebøll
2013-04-23 17:32 ` Marek Lindner
2013-04-20 16:17 ` [B.A.T.M.A.N.] [PATCH 2/3] batman-adv: Receive fragmented packets and merge Martin Hundebøll
2013-04-23 19:17 ` Marek Lindner
2013-04-23 19:30 ` Antonio Quartulli
2013-04-23 19:43 ` Marek Lindner [this message]
2013-04-23 19:47 ` Antonio Quartulli
2013-04-20 16:17 ` [B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Fragment and send skbs larger than mtu Martin Hundebøll
2013-04-23 19:35 ` Marek Lindner
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