Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932424Ab1DMP4x (ORCPT ); Wed, 13 Apr 2011 11:56:53 -0400 Received: from kroah.org ([198.145.64.141]:54664 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932370Ab1DMP4L (ORCPT ); Wed, 13 Apr 2011 11:56:11 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Apr 13 08:51:51 2011 Message-Id: <20110413155150.984826556@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 13 Apr 2011 08:51:38 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Andy Grover , "David S. Miller" Subject: [74/74] net: fix rds_iovec page count overflow In-Reply-To: <20110413155406.GA22568@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1782 Lines: 54 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Linus Torvalds commit 1b1f693d7ad6d193862dcb1118540a030c5e761f upstream. As reported by Thomas Pollet, the rdma page counting can overflow. We get the rdma sizes in 64-bit unsigned entities, but then limit it to UINT_MAX bytes and shift them down to pages (so with a possible "+1" for an unaligned address). So each individual page count fits comfortably in an 'unsigned int' (not even close to overflowing into signed), but as they are added up, they might end up resulting in a signed return value. Which would be wrong. Catch the case of tot_pages turning negative, and return the appropriate error code. Reported-by: Thomas Pollet Signed-off-by: Linus Torvalds Signed-off-by: Andy Grover Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rds/rdma.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/net/rds/rdma.c +++ b/net/rds/rdma.c @@ -473,6 +473,14 @@ static struct rds_rdma_op *rds_rdma_prep max_pages = max(nr, max_pages); nr_pages += nr; + + /* + * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1, + * so tot_pages cannot overflow without first going negative. + */ + if ((int)nr_pages < 0) + ret = -EINVAL; + goto out; } pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/