Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933101AbbGSTSq (ORCPT ); Sun, 19 Jul 2015 15:18:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38883 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932378AbbGSTSm (ORCPT ); Sun, 19 Jul 2015 15:18:42 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxime Coquelin , Mark Brown Subject: [PATCH 4.0 36/58] regmap: Fix possible shift overflow in regmap_field_init() Date: Sun, 19 Jul 2015 12:11:14 -0700 Message-Id: <20150719190812.482666950@linuxfoundation.org> X-Mailer: git-send-email 2.4.6 In-Reply-To: <20150719190811.308546345@linuxfoundation.org> References: <20150719190811.308546345@linuxfoundation.org> User-Agent: quilt/0.64 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: 1705 Lines: 48 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maxime Coquelin commit 921cc29473a0d7c109105c1876ddb432f4a4be7d upstream. The way the mask is generated in regmap_field_init() is wrong. Indeed, a field initialized with msb = 31 and lsb = 0 provokes a shift overflow while calculating the mask field. On some 32 bits architectures, such as x86, the generated mask is 0, instead of the expected 0xffffffff. This patch uses GENMASK() to fix the problem, as this macro is already safe regarding shift overflow. Signed-off-by: Maxime Coquelin Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/base/regmap/regmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -945,11 +945,10 @@ EXPORT_SYMBOL_GPL(devm_regmap_init); static void regmap_field_init(struct regmap_field *rm_field, struct regmap *regmap, struct reg_field reg_field) { - int field_bits = reg_field.msb - reg_field.lsb + 1; rm_field->regmap = regmap; rm_field->reg = reg_field.reg; rm_field->shift = reg_field.lsb; - rm_field->mask = ((BIT(field_bits) - 1) << reg_field.lsb); + rm_field->mask = GENMASK(reg_field.msb, reg_field.lsb); rm_field->id_size = reg_field.id_size; rm_field->id_offset = reg_field.id_offset; } -- 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/