From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70239C4321A for ; Fri, 28 Jun 2019 22:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46AD320828 for ; Fri, 28 Jun 2019 22:49:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727023AbfF1Wt1 (ORCPT ); Fri, 28 Jun 2019 18:49:27 -0400 Received: from mga05.intel.com ([192.55.52.43]:51493 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726891AbfF1WtH (ORCPT ); Fri, 28 Jun 2019 18:49:07 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Jun 2019 15:49:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,429,1557212400"; d="scan'208";a="338039153" Received: from jtkirshe-desk1.jf.intel.com ([134.134.177.96]) by orsmga005.jf.intel.com with ESMTP; 28 Jun 2019 15:49:05 -0700 From: Jeff Kirsher To: davem@davemloft.net Cc: Colin Ian King , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, Andrew Bowers , Jeff Kirsher Subject: [net-next 11/15] iavf: fix dereference of null rx_buffer pointer Date: Fri, 28 Jun 2019 15:49:28 -0700 Message-Id: <20190628224932.3389-12-jeffrey.t.kirsher@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190628224932.3389-1-jeffrey.t.kirsher@intel.com> References: <20190628224932.3389-1-jeffrey.t.kirsher@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Colin Ian King A recent commit efa14c3985828d ("iavf: allow null RX descriptors") added a null pointer sanity check on rx_buffer, however, rx_buffer is being dereferenced before that check, which implies a null pointer dereference bug can potentially occur. Fix this by only dereferencing rx_buffer until after the null pointer check. Addresses-Coverity: ("Dereference before null check") Signed-off-by: Colin Ian King Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/iavf/iavf_txrx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/iavf/iavf_txrx.c b/drivers/net/ethernet/intel/iavf/iavf_txrx.c index 1cde1601bc32..0cca1b589b56 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_txrx.c +++ b/drivers/net/ethernet/intel/iavf/iavf_txrx.c @@ -1296,7 +1296,7 @@ static struct sk_buff *iavf_construct_skb(struct iavf_ring *rx_ring, struct iavf_rx_buffer *rx_buffer, unsigned int size) { - void *va = page_address(rx_buffer->page) + rx_buffer->page_offset; + void *va; #if (PAGE_SIZE < 8192) unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; #else @@ -1308,6 +1308,7 @@ static struct sk_buff *iavf_construct_skb(struct iavf_ring *rx_ring, if (!rx_buffer) return NULL; /* prefetch first cache line of first page */ + va = page_address(rx_buffer->page) + rx_buffer->page_offset; prefetch(va); #if L1_CACHE_BYTES < 128 prefetch(va + L1_CACHE_BYTES); @@ -1362,7 +1363,7 @@ static struct sk_buff *iavf_build_skb(struct iavf_ring *rx_ring, struct iavf_rx_buffer *rx_buffer, unsigned int size) { - void *va = page_address(rx_buffer->page) + rx_buffer->page_offset; + void *va; #if (PAGE_SIZE < 8192) unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; #else @@ -1374,6 +1375,7 @@ static struct sk_buff *iavf_build_skb(struct iavf_ring *rx_ring, if (!rx_buffer) return NULL; /* prefetch first cache line of first page */ + va = page_address(rx_buffer->page) + rx_buffer->page_offset; prefetch(va); #if L1_CACHE_BYTES < 128 prefetch(va + L1_CACHE_BYTES); -- 2.21.0