From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E2853C433F5 for ; Tue, 12 Apr 2022 17:00:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CQQNMw+2GKFTavOpBFv9dusBq40ohLv+d5cK1fdlfRo=; b=41pK+oUkpgic1Y waPz973My/Wc6Qj957VzOBJBCsR+VDxHRmI/ycNzfjqaN0D8ECilftRqV/tGaOTuUvtZmsWUtfcgC BJbDARrXdTluRigChC5OVKi4vtQrQ9GWYX5PIBom9XE/MD/wURbbrg82Why7A6CNjaoVZO1vmEGIp LdMHSq+HlASnhI3o8eGe0tsiztUJL1wKBgY4G6QHlcJqa6vyanRcmlOnN7sdU+QktO8gGElnTy1Ck a6fBGGn9TNqvMB1oXAlRKSyiuolCBWjqTI740PNr/xFn7i72kNySWAVQRB2QidwCe4J5z7fLAJg6i GkY2/hVCsx1uVgWDXxpA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1neJrS-00F9jg-NB; Tue, 12 Apr 2022 16:59:26 +0000 Received: from mail-pl1-x62b.google.com ([2607:f8b0:4864:20::62b]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1neJrP-00F9jM-QS for linux-arm-kernel@lists.infradead.org; Tue, 12 Apr 2022 16:59:25 +0000 Received: by mail-pl1-x62b.google.com with SMTP id s14so7723048plk.8 for ; Tue, 12 Apr 2022 09:59:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=sbmtZUHdeimKmpPh1bMlzq0hwzuYX2yluMhfz3rlFSU=; b=HWCdYoytGsbjpCL3FGrjxUsGb1RC/BkyeetyCir4NM7dpKTa2umTcHsZYPt8Ts5ZRT kkj+OUC2PEuL0b3WmGpSF+16uQqDbUJ5pdvod+3q8BfrGWryansUrTEPMW6R1H6nzHnO E+fPvRLMTZAMVhvfA8aSE9c3Z3BjJxvKXteXI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=sbmtZUHdeimKmpPh1bMlzq0hwzuYX2yluMhfz3rlFSU=; b=ABvFDQocbrv8/nXMxmugnKQ8l+RYv9kILjCWySDYxtDsdNPalKFCW8f+8GSb+hqGVb KYyoYZMkMdUnNhW7rxJEsQMg7kgCX8mdCvQGr15jBYYw6/rCw5Ekr1X/7McVUqQ1xllv kJ+3xiTqouMm74IcThOWte2QWIvxh+k5cdPI9BBYAseYkb/XHDR8IxOL4pcRraOe3Y15 urgeAKKVuW1u4VA0TfUOetVbdsTd4xluQarngCaT7Dihs/wwR6PRskrFw6RP9c5+7stT 25nKAESemL0vfAXDC6fcBiehgF5veyAr/9JVisKS6JS1xsN/On8foTPv+y2W1D61aocM cFlw== X-Gm-Message-State: AOAM530eWAbw/VGy3HS145UlSH9mlTDG57uce1Ltu+laZH2JWg0CLbEF JaQqKkOO6+oWLoP//z+/fExS9u1Pj2aaKw== X-Google-Smtp-Source: ABdhPJw7iU/gNPjilL7EEmCqgRzrhmwbFxKjdbW0t3zk1Pz/3+QxpbfZlGwcC2qUvSClQTbZ5U1T+Q== X-Received: by 2002:a17:90b:4d01:b0:1cd:46e8:215a with SMTP id mw1-20020a17090b4d0100b001cd46e8215amr618262pjb.73.1649782761864; Tue, 12 Apr 2022 09:59:21 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id l4-20020a056a0016c400b004f79504ef9csm39595061pfc.3.2022.04.12.09.59.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Apr 2022 09:59:21 -0700 (PDT) Date: Tue, 12 Apr 2022 09:59:20 -0700 From: Kees Cook To: Ard Biesheuvel Cc: linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org, Marc Zyngier , Will Deacon , Mark Rutland , Catalin Marinas , Mark Brown Subject: Re: [PATCH v3 00/30] arm64: support WXN and entry with MMU enabled Message-ID: <202204120956.B0ECA2FC@keescook> References: <20220411094824.4176877-1-ardb@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220411094824.4176877-1-ardb@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220412_095924_382466_68D2B3E5 X-CRM114-Status: GOOD ( 13.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Apr 11, 2022 at 11:47:54AM +0200, Ard Biesheuvel wrote: > - allow WXN to be enabled (with an opt-out) so writable mappings are > never executable; Besides all the rest of this series's awesomeness; this really stands out to me. I didn't even know this was a feature in aarch64. Nice! I really like the idea of having this enabled -- anything executing out of a writable mapping should already be considered a mistake (and tons of work over the last 2 decades has already gone into making stuff this doesn't happen in both the kernel and userspace). We could even make a new LKDTM test for this. (Right now stuff like EXEC_DATA just verifies that the .data segment doesn't have the X bit... but adding something like EXEC_WXN where a memory region is made explicitly W+X, and it _still_ can't be executed would be great.) Cool! -Kees -- Kees Cook _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel