From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753326AbbK2WBY (ORCPT ); Sun, 29 Nov 2015 17:01:24 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:56478 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753282AbbK2WBR (ORCPT ); Sun, 29 Nov 2015 17:01:17 -0500 Message-Id: <20151129214704.374978763@1wt.eu> User-Agent: quilt/0.63-1 Date: Sun, 29 Nov 2015 22:47:37 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sowmini Varadhan , Santosh Shilimkar , "David S. Miller" , Ben Hutchings , Willy Tarreau Subject: [PATCH 2.6.32 35/38] [PATCH 35/38] RDS-TCP: Recover correctly from pskb_pull()/pksb_trim() failure in rds_tcp_data_recv MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 In-Reply-To: <8acf8256ccc72771a80b7851061027bc@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 8ce675ff39b9958d1c10f86cf58e357efaafc856 ] Either of pskb_pull() or pskb_trim() may fail under low memory conditions. If rds_tcp_data_recv() ignores such failures, the application will receive corrupted data because the skb has not been correctly carved to the RDS datagram size. Avoid this by handling pskb_pull/pskb_trim failure in the same manner as the skb_clone failure: bail out of rds_tcp_data_recv(), and retry via the deferred call to rds_send_worker() that gets set up on ENOMEM from rds_tcp_read_sock() Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit f114d9374ba3e42c86b112c8b4dbcba50a7330e7) Signed-off-by: Willy Tarreau --- net/rds/tcp_recv.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/net/rds/tcp_recv.c b/net/rds/tcp_recv.c index c00daff..43d9d66 100644 --- a/net/rds/tcp_recv.c +++ b/net/rds/tcp_recv.c @@ -233,8 +233,15 @@ static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb, } to_copy = min(tc->t_tinc_data_rem, left); - pskb_pull(clone, offset); - pskb_trim(clone, to_copy); + if (!pskb_pull(clone, offset) || + pskb_trim(clone, to_copy)) { + printk(KERN_WARNING "rds_tcp_data_recv: pull/trim failed " + "left %zu data_rem %zu skb_len %d\n", + left, tc->t_tinc_data_rem, skb->len); + kfree_skb(clone); + desc->error = -ENOMEM; + goto out; + } skb_queue_tail(&tinc->ti_skb_list, clone); rdsdebug("skb %p data %p len %d off %u to_copy %zu -> " -- 1.7.12.2.21.g234cd45.dirty