Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751309AbdH1IGZ (ORCPT ); Mon, 28 Aug 2017 04:06:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60814 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbdH1IGV (ORCPT ); Mon, 28 Aug 2017 04:06:21 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Jakub Kicinski , "David S. Miller" Subject: [PATCH 4.12 15/99] nfp: fix infinite loop on umapping cleanup Date: Mon, 28 Aug 2017 10:04:13 +0200 Message-Id: <20170828080456.588017927@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170828080455.968552605@linuxfoundation.org> References: <20170828080455.968552605@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1247 Lines: 37 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Colin Ian King [ Upstream commit eac2c68d663effb077210218788952b5a0c1f60e ] The while loop that performs the dma page unmapping never decrements index counter f and hence loops forever. Fix this with a pre-decrement on f. Detected by CoverityScan, CID#1357309 ("Infinite loop") Fixes: 4c3523623dc0 ("net: add driver for Netronome NFP4000/NFP6000 NIC VFs") Signed-off-by: Colin Ian King Acked-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -881,8 +881,7 @@ static int nfp_net_tx(struct sk_buff *sk return NETDEV_TX_OK; err_unmap: - --f; - while (f >= 0) { + while (--f >= 0) { frag = &skb_shinfo(skb)->frags[f]; dma_unmap_page(dp->dev, tx_ring->txbufs[wr_idx].dma_addr, skb_frag_size(frag), DMA_TO_DEVICE);