Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756839AbdDPKyD (ORCPT ); Sun, 16 Apr 2017 06:54:03 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59410 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756475AbdDPKx4 (ORCPT ); Sun, 16 Apr 2017 06:53:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rasmus Villemoes , Jiri Kosina , Randy Dunlap , Andrew Morton , Linus Torvalds Subject: [PATCH 3.18 060/145] lib/vsprintf.c: improve sanity check in vsnprintf() Date: Sun, 16 Apr 2017 12:49:13 +0200 Message-Id: <20170416080203.759043246@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170416080200.205458595@linuxfoundation.org> References: <20170416080200.205458595@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1193 Lines: 36 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rasmus Villemoes commit 2aa2f9e21e4eb25c720b2e7d80f8929638f6ad73 upstream. On 64 bit, size may very well be huge even if bit 31 happens to be 0. Somehow it doesn't feel right that one can pass a 5 GiB buffer but not a 3 GiB one. So cap at INT_MAX as was probably the intention all along. This is also the made-up value passed by sprintf and vsprintf. Signed-off-by: Rasmus Villemoes Cc: Jiri Kosina Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- lib/vsprintf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1728,7 +1728,7 @@ int vsnprintf(char *buf, size_t size, co /* Reject out-of-range values early. Large positive sizes are used for unknown buffer sizes. */ - if (WARN_ON_ONCE((int) size < 0)) + if (WARN_ON_ONCE(size > INT_MAX)) return 0; str = buf;