From patchwork Wed May 24 15:57:50 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: 9746315 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 6F540601C2 for ; Wed, 24 May 2017 15:58:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E7722236A for ; Wed, 24 May 2017 15:58:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 52C8128986; Wed, 24 May 2017 15:58:42 +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=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DC4772236A for ; Wed, 24 May 2017 15:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=yiNc72xE65L0aja2EO3I94Q8t5Iflct/rrRJtl6aY4U=; b=fYhFqOEPjOiGpqwn18Zy+oeerl g0o8Ozl89uhUTZ3eyaAQKqTrIJPjNSZtxflEFyVFysSinKfuPn3c3iIYfzOrEc/uNZoD7J5zF5LSq BmCuWZ4oyWL8TSgCbh74hrpXlfzLdUlCKlK8/fBQr8nuBxiYqYGGOz1POJNcjSPXJWKcquDiHKW2l 0kIlklD8Bm4RhS3JLGi24ocBZHj/IgIzegVqPD8AaWnvWTbg22w5r+hBoXqVEndQl0I6JGB9EAgad tIdaMkxWiE8/CLXVyFlMZn2Eag5RT+Zuqv0xdTzecVgQsqj+Y5OwqukwKHWNoW46UcyVZj/80t04l gH09yWdw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dDYgJ-0006fT-Ky; Wed, 24 May 2017 15:58:39 +0000 Received: from shelob.surriel.com ([96.67.55.147]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dDYg5-0006NL-7Y for linux-arm-kernel@lists.infradead.org; Wed, 24 May 2017 15:58:27 +0000 Received: from [2001:470:1f07:12aa:224:e8ff:fe38:995c] (helo=annuminas.surriel.com) by shelob.surriel.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1dDYfd-0004jy-17; Wed, 24 May 2017 11:57:57 -0400 Received: from annuminas.surriel.com (localhost.localdomain [127.0.0.1]) by annuminas.surriel.com (8.15.2/8.14.5) with ESMTP id v4OFvuXF000744; Wed, 24 May 2017 11:57:56 -0400 Received: (from riel@localhost) by annuminas.surriel.com (8.15.2/8.15.2/Submit) id v4OFvu96000743; Wed, 24 May 2017 11:57:56 -0400 X-Authentication-Warning: annuminas.surriel.com: riel set sender to riel@redhat.com using -f From: riel@redhat.com To: linux-kernel@vger.kernel.org Subject: [PATCH 4/5] arm64: ascii armor the arm64 boot init stack canary Date: Wed, 24 May 2017 11:57:50 -0400 Message-Id: <20170524155751.424-5-riel@redhat.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170524155751.424-1-riel@redhat.com> References: <20170524155751.424-1-riel@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170524_085825_408024_9DD01DE7 X-CRM114-Status: UNSURE ( 8.18 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tytso@mit.edu, keescook@chromium.org, ysato@users.sourceforge.jp, linux-sh@vger.kernel.org, catalin.marinas@arm.com, x86@kernel.org, luto@amacapital.net, danielmicay@gmail.com, hpa@zytor.com, kernel-hardening@lists.openwall.com, mingo@kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rik van Riel 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/arm64/include/asm/stackprotector.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h index fe5e287dc56b..b86a0865ddf1 100644 --- a/arch/arm64/include/asm/stackprotector.h +++ b/arch/arm64/include/asm/stackprotector.h @@ -30,6 +30,7 @@ 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;