From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753526AbbI3PbK (ORCPT ); Wed, 30 Sep 2015 11:31:10 -0400 Received: from mail-la0-f50.google.com ([209.85.215.50]:34856 "EHLO mail-la0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752385AbbI3PbF (ORCPT ); Wed, 30 Sep 2015 11:31:05 -0400 From: Rasmus Villemoes To: Andrew Morton Cc: Tejun Heo , Andy Shevchenko , linux-kernel@vger.kernel.org, Kees Cook , Joe Perches , Rasmus Villemoes Subject: [PATCH v2 2/4] lib/vsprintf.c: also improve sanity check in bstr_printf() Date: Wed, 30 Sep 2015 17:30:49 +0200 Message-Id: <1443627051-14003-3-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1443627051-14003-1-git-send-email-linux@rasmusvillemoes.dk> References: <1443202865-25533-1-git-send-email-linux@rasmusvillemoes.dk> <1443627051-14003-1-git-send-email-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting from 2aa2f9e21e4e ("lib/vsprintf.c: improve sanity check in vsnprintf()"): 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. I should have seen this copy-pasted instance back then, but let's just do it now. Acked-by: Kees Cook Signed-off-by: Rasmus Villemoes --- v2: add ack. lib/vsprintf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index f2590a80937f..03fa10b4be96 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2294,7 +2294,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) char *str, *end; const char *args = (const char *)bin_buf; - if (WARN_ON_ONCE((int) size < 0)) + if (WARN_ON_ONCE(size > INT_MAX)) return 0; str = buf; -- 2.1.3