From patchwork Wed May 24 16:34:46 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rik van Riel X-Patchwork-Id: 9746395 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 513EA601C2 for ; Wed, 24 May 2017 16:34:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 428E7289BA for ; Wed, 24 May 2017 16:34:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 410FB289CC; Wed, 24 May 2017 16:34:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7D3AC289BA for ; Wed, 24 May 2017 16:34:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034490AbdEXQe5 (ORCPT ); Wed, 24 May 2017 12:34:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32888 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030748AbdEXQe4 (ORCPT ); Wed, 24 May 2017 12:34:56 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 97935C04B939; Wed, 24 May 2017 16:34:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 97935C04B939 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=riel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 97935C04B939 Received: from annuminas.surriel.com (ovpn-123-130.rdu2.redhat.com [10.10.123.130]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0A7A57D6B3; Wed, 24 May 2017 16:34:53 +0000 (UTC) Date: Wed, 24 May 2017 12:34:46 -0400 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: danielmicay@gmail.com, tytso@mit.edu, keescook@chromium.org, hpa@zytor.com, luto@amacapital.net, mingo@kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux-sh@vger.kernel.org, ysato@users.sourceforge.jp, kernel-hardening@lists.openwall.com Subject: [PATCH 5/5] sh64: ascii armor the sh64 boot init stack canary Message-ID: <20170524123446.78510066@annuminas.surriel.com> In-Reply-To: <20170524155751.424-1-riel@redhat.com> References: <20170524155751.424-1-riel@redhat.com> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 24 May 2017 16:34:55 +0000 (UTC) Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use the ascii-armor canary to prevent unterminated C string overflows from being able to successfully overwrite the canary, even if they somehow obtain the canary value. Inspired by execshield ascii-armor and Daniel Micay's linux-hardened tree. Signed-off-by: Rik van Riel Acked-by: Kees Cook --- arch/sh/include/asm/stackprotector.h | 1 + 1 file changed, 1 insertion(+) -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/sh/include/asm/stackprotector.h b/arch/sh/include/asm/stackprotector.h index d9df3a76847c..141515a43b78 100644 --- a/arch/sh/include/asm/stackprotector.h +++ b/arch/sh/include/asm/stackprotector.h @@ -19,6 +19,7 @@ static __always_inline void boot_init_stack_canary(void) /* Try to get a semi random initial value. */ get_random_bytes(&canary, sizeof(canary)); canary ^= LINUX_VERSION_CODE; + canary &= CANARY_MASK; current->stack_canary = canary; __stack_chk_guard = current->stack_canary;