Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755411AbaBEUIZ (ORCPT ); Wed, 5 Feb 2014 15:08:25 -0500 Received: from mail1.windriver.com ([147.11.146.13]:48606 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755321AbaBEUIA (ORCPT ); Wed, 5 Feb 2014 15:08:00 -0500 From: Paul Gortmaker To: , CC: Mathias Krause , Gerrit Renker , "David S. Miller" , Paul Gortmaker Subject: [v2.6.34-stable 193/213] dccp: check ccid before dereferencing Date: Wed, 5 Feb 2014 15:02:28 -0500 Message-ID: <1391630568-49251-194-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mathias Krause ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 276bdb82dedb290511467a5a4fdbe9f0b52dce6f upstream. ccid_hc_rx_getsockopt() and ccid_hc_tx_getsockopt() might be called with a NULL ccid pointer leading to a NULL pointer dereference. This could lead to a privilege escalation if the attacker is able to map page 0 and prepare it with a fake ccid_ops pointer. Signed-off-by: Mathias Krause Cc: Gerrit Renker Signed-off-by: David S. Miller Signed-off-by: Paul Gortmaker --- net/dccp/ccid.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h index 6df6f8ac9636..4f78abbf1045 100644 --- a/net/dccp/ccid.h +++ b/net/dccp/ccid.h @@ -218,7 +218,7 @@ static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk, u32 __user *optval, int __user *optlen) { int rc = -ENOPROTOOPT; - if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL) + if (ccid != NULL && ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL) rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len, optval, optlen); return rc; @@ -229,7 +229,7 @@ static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk, u32 __user *optval, int __user *optlen) { int rc = -ENOPROTOOPT; - if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL) + if (ccid != NULL && ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL) rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len, optval, optlen); return rc; -- 1.8.5.2 -- 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/