Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752071AbaLYCuO (ORCPT ); Wed, 24 Dec 2014 21:50:14 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53193 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751651AbaLYCuM (ORCPT ); Wed, 24 Dec 2014 21:50:12 -0500 Date: Wed, 24 Dec 2014 18:50:11 -0800 From: Greg KH To: "Ahmed S. Darwish" Cc: Olivier Sobrie , Oliver Hartkopp , Wolfgang Grandegger , Marc Kleine-Budde , "David S. Miller" , Paul Gortmaker , Linux-CAN , netdev , Linux-stable , LKML Subject: Re: [PATCH v2 1/4] can: kvaser_usb: Don't free packets when tight on URBs Message-ID: <20141225025011.GA10491@kroah.com> References: <20141223154654.GB6460@vivalin-002> <20141224235644.GA3778@vivalin-002> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141224235644.GA3778@vivalin-002> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 25, 2014 at 01:56:44AM +0200, Ahmed S. Darwish wrote: > From: Ahmed S. Darwish > > Flooding the Kvaser CAN to USB dongle with multiple reads and > writes in high frequency caused seemingly-random panics in the > kernel. > > On further inspection, it seems the driver erroneously freed the > to-be-transmitted packet upon getting tight on URBs and returning > NETDEV_TX_BUSY, leading to invalid memory writes and double frees > at a later point in time. > > Note: > > Finding no more URBs/transmit-contexts and returning NETDEV_TX_BUSY > is a driver bug in and out of itself: it means that our start/stop > queue flow control is broken. > > This patch only fixes the (buggy) error handling code; the root > cause shall be fixed in a later commit. > > Signed-off-by: Ahmed S. Darwish > --- > drivers/net/can/usb/kvaser_usb.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > (Marc, Greg, I believe this should also be added to -stable?) This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. -- 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/