Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757838Ab2KVVrj (ORCPT ); Thu, 22 Nov 2012 16:47:39 -0500 Received: from mail.kernel.org ([198.145.19.201]:49646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755024Ab2KVSkX (ORCPT ); Thu, 22 Nov 2012 13:40:23 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Xi Wang , Alex Elder Subject: [ 112/171] libceph: fix overflow in osdmap_decode() Date: Wed, 21 Nov 2012 16:40:58 -0800 Message-Id: <20121122004044.590722021@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.197.g5a90748 In-Reply-To: <20121122004033.298367941@linuxfoundation.org> References: <20121122004033.298367941@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1337 Lines: 38 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xi Wang (cherry picked from commit e91a9b639a691e0982088b5954eaafb5a25c8f1c) On 32-bit systems, a large `n' would overflow `n * sizeof(u32)' and bypass the check ceph_decode_need(p, end, n * sizeof(u32), bad). It would also overflow the subsequent kmalloc() size, leading to out-of-bounds write. Signed-off-by: Xi Wang Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- net/ceph/osdmap.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -674,6 +674,9 @@ struct ceph_osdmap *osdmap_decode(void * ceph_decode_need(p, end, sizeof(u32) + sizeof(u64), bad); ceph_decode_copy(p, &pgid, sizeof(pgid)); n = ceph_decode_32(p); + err = -EINVAL; + if (n > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) + goto bad; ceph_decode_need(p, end, n * sizeof(u32), bad); err = -ENOMEM; pg = kmalloc(sizeof(*pg) + n*sizeof(u32), GFP_NOFS); -- 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/