From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932610Ab2JAXAF (ORCPT ); Mon, 1 Oct 2012 19:00:05 -0400 Received: from 1wt.eu ([62.212.114.60]:35063 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932575Ab2JAW77 (ORCPT ); Mon, 1 Oct 2012 18:59:59 -0400 Message-Id: <20121001225159.734955658@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 02 Oct 2012 00:52:47 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jason Wang , "David S. Miller" , Willy Tarreau Subject: [ 050/180] net: sock: validate data_len before allocating skb in sock_alloc_send_pskb() In-Reply-To: <6a854f579a99b4fe2efaca1057e8ae22@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. ------------------ From: Jason Wang commit cc9b17ad29ecaa20bfe426a8d4dbfb94b13ff1cc upstream We need to validate the number of pages consumed by data_len, otherwise frags array could be overflowed by userspace. So this patch validate data_len and return -EMSGSIZE when data_len may occupies more frags than MAX_SKB_FRAGS. Signed-off-by: Jason Wang Signed-off-by: David S. Miller [dannf: backported to Debian's 2.6.32] Signed-off-by: Willy Tarreau --- net/core/sock.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 6605e75..4538a34 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1391,6 +1391,11 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, gfp_t gfp_mask; long timeo; int err; + int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT; + + err = -EMSGSIZE; + if (npages > MAX_SKB_FRAGS) + goto failure; gfp_mask = sk->sk_allocation; if (gfp_mask & __GFP_WAIT) @@ -1409,14 +1414,12 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) { skb = alloc_skb(header_len, gfp_mask); if (skb) { - int npages; int i; /* No pages, we're done... */ if (!data_len) break; - npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT; skb->truesize += data_len; skb_shinfo(skb)->nr_frags = npages; for (i = 0; i < npages; i++) { -- 1.7.2.1.45.g54fbc