From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933730Ab0HXXLg (ORCPT ); Tue, 24 Aug 2010 19:11:36 -0400 Received: from kroah.org ([198.145.64.141]:41307 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933200Ab0HXXDM (ORCPT ); Tue, 24 Aug 2010 19:03:12 -0400 X-Mailbox-Line: From gregkh@clark.site Tue Aug 24 15:45:08 2010 Message-Id: <20100824224508.354686241@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 24 Aug 2010 15:45:27 -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, Oliver Hartkopp , "David S. Miller" Subject: [082/114] can-raw: Fix skb_orphan_try handling In-Reply-To: <20100824224610.GA5424@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Oliver Hartkopp commit cff0d6e6edac7672b3f915bb4fb59f279243b7f9 upstream. Commit fc6055a5ba31e2c14e36e8939f9bf2b6d586a7f5 (net: Introduce skb_orphan_try()) allows an early orphan of the skb and takes care on tx timestamping, which needs the sk-reference in the skb on driver level. So does the can-raw socket, which has not been taken into account here. The patch below adds a 'prevent_sk_orphan' bit in the skb tx shared info, which fixes the problem discovered by Matthias Fuchs here: http://marc.info/?t=128030411900003&r=1&w=2 Even if it's not a primary tx timestamp topic it fits well into some skb shared tx context. Or should be find a different place for the information to protect the sk reference until it reaches the driver level? Signed-off-by: Oliver Hartkopp Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/skbuff.h | 4 +++- net/can/raw.c | 4 ++++ 2 files changed, 7 insertions(+), 1 deletion(-) --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -169,6 +169,7 @@ struct skb_shared_hwtstamps { * @software: generate software time stamp * @in_progress: device driver is going to provide * hardware time stamp + * @prevent_sk_orphan: make sk reference available on driver level * @flags: all shared_tx flags * * These flags are attached to packets as part of the @@ -178,7 +179,8 @@ union skb_shared_tx { struct { __u8 hardware:1, software:1, - in_progress:1; + in_progress:1, + prevent_sk_orphan:1; }; __u8 flags; }; --- a/net/can/raw.c +++ b/net/can/raw.c @@ -655,6 +655,10 @@ static int raw_sendmsg(struct kiocb *ioc err = sock_tx_timestamp(msg, sk, skb_tx(skb)); if (err < 0) goto free_skb; + + /* to be able to check the received tx sock reference in raw_rcv() */ + skb_tx(skb)->prevent_sk_orphan = 1; + skb->dev = dev; skb->sk = sk;