From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754094AbbITAcX (ORCPT ); Sat, 19 Sep 2015 20:32:23 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:42964 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753511AbbITAcS (ORCPT ); Sat, 19 Sep 2015 20:32:18 -0400 From: Mark Brown To: Rasmus Villemoes Cc: linux-kernel@vger.kernel.org, Mark Brown , stable@vger.kernel.org Date: Sat, 19 Sep 2015 07:37:49 -0700 Message-Id: <1442673471-26849-1-git-send-email-broonie@kernel.org> X-Mailer: git-send-email 2.5.0 X-SA-Exim-Connect-IP: 209.49.225.226 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: [PATCH 1/3] regmap: debugfs: Ensure we don't underflow when printing access masks X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a read is attempted which is smaller than the line length then we may underflow the subtraction we're doing with the unsigned size_t type so move some of the calculation to be additions on the right hand side instead in order to avoid this. Reported-by: Rasmus Villemoes Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/base/regmap/regmap-debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index f42f2ba..1f32789 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -432,7 +432,7 @@ static ssize_t regmap_access_read_file(struct file *file, /* If we're in the region the user is trying to read */ if (p >= *ppos) { /* ...but not beyond it */ - if (buf_pos >= count - 1 - tot_len) + if (buf_pos + tot_len + 1 >= count) break; /* Format the register */ -- 2.5.0