Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932587AbbKLXTo (ORCPT ); Thu, 12 Nov 2015 18:19:44 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:45368 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932505AbbKLXTb (ORCPT ); Thu, 12 Nov 2015 18:19:31 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Pravin B Shelar , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 092/155] skbuff: Fix skb checksum partial check. Date: Thu, 12 Nov 2015 15:17:26 -0800 Message-Id: <1447370309-357-93-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1447370309-357-1-git-send-email-kamal@canonical.com> References: <1447370309-357-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2323 Lines: 69 3.19.8-ckt10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Pravin B Shelar [ Upstream commit 31b33dfb0a144469dd805514c9e63f4993729a48 ] Earlier patch 6ae459bda tried to detect void ckecksum partial skb by comparing pull length to checksum offset. But it does not work for all cases since checksum-offset depends on updates to skb->data. Following patch fixes it by validating checksum start offset after skb-data pointer is updated. Negative value of checksum offset start means there is no need to checksum. Fixes: 6ae459bda ("skbuff: Fix skb checksum flag on skb pull") Reported-by: Andrew Vagin Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- include/linux/skbuff.h | 2 +- net/core/skbuff.c | 9 +++++---- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 8271178..b0e064e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2576,7 +2576,7 @@ static inline void skb_postpull_rcsum(struct sk_buff *skb, if (skb->ip_summed == CHECKSUM_COMPLETE) skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); else if (skb->ip_summed == CHECKSUM_PARTIAL && - skb_checksum_start_offset(skb) <= len) + skb_checksum_start_offset(skb) < 0) skb->ip_summed = CHECKSUM_NONE; } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0998af7..ce3b085 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2979,11 +2979,12 @@ EXPORT_SYMBOL(skb_append_datato_frags); */ unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len) { + unsigned char *data = skb->data; + BUG_ON(len > skb->len); - skb->len -= len; - BUG_ON(skb->len < skb->data_len); - skb_postpull_rcsum(skb, skb->data, len); - return skb->data += len; + __skb_pull(skb, len); + skb_postpull_rcsum(skb, data, len); + return skb->data; } EXPORT_SYMBOL_GPL(skb_pull_rcsum); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/