From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757234AbaH1BFh (ORCPT ); Wed, 27 Aug 2014 21:05:37 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:46606 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757122AbaH1BFe (ORCPT ); Wed, 27 Aug 2014 21:05:34 -0400 From: Benjamin Poirier To: Prashant Sreedharan , Michael Chan Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net v4 2/4] tg3: Fix tx_pending check for MAX_SKB_FRAGS Date: Wed, 27 Aug 2014 18:04:16 -0700 Message-Id: <1409187858-7698-2-git-send-email-bpoirier@suse.de> X-Mailer: git-send-email 1.8.4.5 In-Reply-To: <1409187858-7698-1-git-send-email-bpoirier@suse.de> References: <1409187858-7698-1-git-send-email-bpoirier@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The rest of the driver assumes at least one free descriptor in the tx ring. Therefore, since an skb with max frags takes up (MAX_SKB_FRAGS + 1) descriptors, tx_pending must be > (MAX_SKB_FRAGS + 1). Signed-off-by: Benjamin Poirier --- Changes v1->v2 Moved ahead in the series from 3/3 to 2/3, no functionnal change I reproduced this bug using the same approach explained in patch 1. The bug reproduces with tx_pending = 18 --- drivers/net/ethernet/broadcom/tg3.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index b11c0fd..0cecd6d 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -12319,7 +12319,7 @@ static int tg3_set_ringparam(struct net_device *dev, struct ethtool_ringparam *e if ((ering->rx_pending > tp->rx_std_ring_mask) || (ering->rx_jumbo_pending > tp->rx_jmb_ring_mask) || (ering->tx_pending > TG3_TX_RING_SIZE - 1) || - (ering->tx_pending <= MAX_SKB_FRAGS) || + (ering->tx_pending <= MAX_SKB_FRAGS + 1) || (tg3_flag(tp, TSO_BUG) && (ering->tx_pending <= (MAX_SKB_FRAGS * 3)))) return -EINVAL; -- 1.8.4.5