Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933410AbbKMAEI (ORCPT ); Thu, 12 Nov 2015 19:04:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:45022 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932343AbbKLXTA (ORCPT ); Thu, 12 Nov 2015 18:19:00 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mark Brown , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 036/155] regmap: debugfs: Ensure we don't underflow when printing access masks Date: Thu, 12 Nov 2015 15:16:30 -0800 Message-Id: <1447370309-357-37-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1447370309-357-1-git-send-email-kamal@canonical.com> References: <1447370309-357-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1476 Lines: 41 3.19.8-ckt10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Brown commit b763ec17ac762470eec5be8ebcc43e4f8b2c2b82 upstream. 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 Signed-off-by: Kamal Mostafa --- 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 5799a0b..1f6cd15 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 */ -- 1.9.1 -- 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/