From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net] ixgbe: fix possible null buffer error Date: Tue, 20 Sep 2011 18:13:03 -0700 Message-ID: <1316567583-28673-1-git-send-email-jeffrey.t.kirsher@intel.com> Cc: Jesse Brandeburg , netdev@vger.kernel.org, gospo@redhat.com, Alexander Duyck , stable@kernel.org, Jeff Kirsher To: davem@davemloft.net Return-path: Received: from mga14.intel.com ([143.182.124.37]:45168 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750711Ab1IUBNG (ORCPT ); Tue, 20 Sep 2011 21:13:06 -0400 Sender: netdev-owner@vger.kernel.org List-ID: From: Jesse Brandeburg It seems that at least one PPC machine would occasionally give a (valid) 0 as the return value from dma_map, this caused the ixgbe code to not work correctly. A fix is pending in the PPC tree to not return 0 from dma map, but we can also fix the driver to make sure we don't mess up in other arches as well. This patch is applicable to all current stable kernels. Ref: https://bugzilla.redhat.com/show_bug.cgi?id=683611 Reported-by: Neil Horman Signed-off-by: Jesse Brandeburg CC: Alexander Duyck CC: stable@kernel.org Tested-by: Thadeu Lima de Souza Cascardo Tested-by: Phil Schmitt Signed-off-by: Jeff Kirsher --- drivers/net/ixgbe/ixgbe_main.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c index 2279039..e1fcc95 100644 --- a/drivers/net/ixgbe/ixgbe_main.c +++ b/drivers/net/ixgbe/ixgbe_main.c @@ -1321,8 +1321,8 @@ static void ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, if (ring_is_rsc_enabled(rx_ring)) pkt_is_rsc = ixgbe_get_rsc_state(rx_desc); - /* if this is a skb from previous receive DMA will be 0 */ - if (rx_buffer_info->dma) { + /* linear means we are building an skb from multiple pages */ + if (!skb_is_nonlinear(skb)) { u16 hlen; if (pkt_is_rsc && !(staterr & IXGBE_RXD_STAT_EOP) && -- 1.7.6.2