From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933135Ab3B1Oy7 (ORCPT ); Thu, 28 Feb 2013 09:54:59 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42541 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933098Ab3B1OvK (ORCPT ); Thu, 28 Feb 2013 09:51:10 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Wei Liu , Jan Beulich , David Vrabel , "David S. Miller" , Luis Henriques Subject: [PATCH 127/139] xen-netback: correctly return errors from netbk_count_requests() Date: Thu, 28 Feb 2013 14:44:37 +0000 Message-Id: <1362062689-2567-128-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> References: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: David Vrabel commit 35876b5ffc154c357476b2c3bdab10feaf4bd8f0 upstream. netbk_count_requests() could detect an error, call netbk_fatal_tx_error() but return 0. The vif may then be used afterwards (e.g., in a call to netbk_tx_error(). Since netbk_fatal_tx_error() could set vif->refcnt to 1, the vif may be freed immediately after the call to netbk_fatal_tx_error() (e.g., if the vif is also removed). Netback thread Xenwatch thread ------------------------------------------- netbk_fatal_tx_err() netback_remove() xenvif_disconnect() ... free_netdev() netbk_tx_err() Oops! Signed-off-by: Wei Liu Signed-off-by: Jan Beulich Signed-off-by: David Vrabel Reported-by: Christopher S. Aker Acked-by: Ian Campbell Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- drivers/net/xen-netback/netback.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index f3c3a68..a98f012 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -882,13 +882,13 @@ static int netbk_count_requests(struct xenvif *vif, if (frags >= work_to_do) { netdev_err(vif->dev, "Need more frags\n"); netbk_fatal_tx_err(vif); - return -frags; + return -ENODATA; } if (unlikely(frags >= MAX_SKB_FRAGS)) { netdev_err(vif->dev, "Too many frags\n"); netbk_fatal_tx_err(vif); - return -frags; + return -E2BIG; } memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + frags), @@ -896,7 +896,7 @@ static int netbk_count_requests(struct xenvif *vif, if (txp->size > first->size) { netdev_err(vif->dev, "Frag is bigger than frame.\n"); netbk_fatal_tx_err(vif); - return -frags; + return -EIO; } first->size -= txp->size; @@ -906,7 +906,7 @@ static int netbk_count_requests(struct xenvif *vif, netdev_err(vif->dev, "txp->offset: %x, size: %u\n", txp->offset, txp->size); netbk_fatal_tx_err(vif); - return -frags; + return -EINVAL; } } while ((txp++)->flags & XEN_NETTXF_more_data); return frags; -- 1.8.1.2