From: Mel Gorman <mgorman@suse.de>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Miller <davem@davemloft.net>,
Ian Campbell <Ian.Campbell@eu.citrix.com>,
xen-devel@lists.xensource.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
konrad@darnok.org, akpm@linux-foundation.org
Subject: Re: [Xen-devel] [PATCH] netvm: check for page == NULL when propogating the skb->pfmemalloc flag
Date: Tue, 14 Aug 2012 11:05:22 +0100 [thread overview]
Message-ID: <20120814100522.GL4177@suse.de> (raw)
In-Reply-To: <20120813154144.GA24868@phenom.dumpdata.com>
On Mon, Aug 13, 2012 at 11:41:44AM -0400, Konrad Rzeszutek Wilk wrote:
> On Wed, Aug 08, 2012 at 03:50:46PM -0700, David Miller wrote:
> > From: Mel Gorman <mgorman@suse.de>
> > Date: Tue, 7 Aug 2012 09:55:55 +0100
> >
> > > Commit [c48a11c7: netvm: propagate page->pfmemalloc to skb] is responsible
> > > for the following bug triggered by a xen network driver
> > ...
> > > The problem is that the xenfront driver is passing a NULL page to
> > > __skb_fill_page_desc() which was unexpected. This patch checks that
> > > there is a page before dereferencing.
> > >
> > > Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > > Signed-off-by: Mel Gorman <mgorman@suse.de>
> >
> > That call to __skb_fill_page_desc() in xen-netfront.c looks completely bogus.
> > It's the only driver passing NULL here.
>
> It looks to be passing a valid page pointer (at least by looking
> at the code) so I am not sure how it got turned in a NULL.
>
Are we looking at different code bases? I see this and I was assuming it
was the source of the bug.
__skb_fill_page_desc(skb, 0, NULL, 0, 0);
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2012-08-14 10:05 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 8:55 [PATCH] netvm: check for page == NULL when propogating the skb->pfmemalloc flag Mel Gorman
2012-08-08 19:14 ` Rik van Riel
2012-08-08 22:50 ` David Miller
2012-08-13 10:26 ` Mel Gorman
2012-08-13 10:47 ` Mel Gorman
2012-08-13 18:56 ` Jeremy Fitzhardinge
2012-08-14 10:18 ` Mel Gorman
2012-08-13 15:41 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-08-14 10:05 ` Mel Gorman [this message]
2012-08-14 13:28 ` Konrad Rzeszutek Wilk
2012-08-22 10:26 ` Ian Campbell
2012-08-23 14:17 ` Konrad Rzeszutek Wilk
2012-08-30 16:24 ` David Miller
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