From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 27 Apr 2018 16:04:33 +0200 (CEST) Received: from mail.kernel.org ([198.145.29.99]:46076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23994654AbeD0OEXSsmmV (ORCPT ); Fri, 27 Apr 2018 16:04:23 +0200 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 55C1521890; Fri, 27 Apr 2018 14:04:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55C1521890 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Burton , Rob Herring , Grant Likely , Frank Rowand , devicetree@vger.kernel.org, linux-mips@linux-mips.org, Ralf Baechle , Amit Pundir Subject: [PATCH 4.9 15/74] OF: Prevent unaligned access in of_alias_scan() Date: Fri, 27 Apr 2018 15:58:05 +0200 Message-Id: <20180427135710.534544535@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180427135709.899303463@linuxfoundation.org> References: <20180427135709.899303463@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 63814 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Burton commit de96ec2a77c6d06a423c2c495bb4a2f4299f3d9e upstream. When allocating a struct alias_prop, of_alias_scan() only requested that it be aligned on a 4 byte boundary. The struct contains pointers which leads to us attempting 64 bit writes on 64 bit systems, and if the CPU doesn't support unaligned memory accesses then this causes problems - for example on some MIPS64r2 CPUs including the "mips64r2-generic" QEMU emulated CPU it will trigger an address error exception. Fix this by requesting alignment for the struct alias_prop allocation matching that which the compiler expects, using the __alignof__ keyword. Signed-off-by: Paul Burton Acked-by: Rob Herring Reviewed-by: Grant Likely Cc: Frank Rowand Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14306/ Signed-off-by: Ralf Baechle Cc: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- drivers/of/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -2109,7 +2109,7 @@ void of_alias_scan(void * (*dt_alloc)(u6 continue; /* Allocate an alias_prop with enough space for the stem */ - ap = dt_alloc(sizeof(*ap) + len + 1, 4); + ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap)); if (!ap) continue; memset(ap, 0, sizeof(*ap) + len + 1);