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 X-Spam-Level: X-Spam-Status: No, score=-14.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD971C433E0 for ; Thu, 18 Mar 2021 18:45:24 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 57C4464F01 for ; Thu, 18 Mar 2021 18:45:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 57C4464F01 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GlrUg5b8xq77C4P+165J3xHEqPvpr+CVb9fMpMKix7o=; b=bYuR1KKFHqydrd4PrhKAkDVBV f7vlnJBTLCHV0MZ1mdwxU0E2/bYXbkiUTisQ3en5XIxOvdIEE1M33oViKzE2ffDDVJp7joDMWNgF8 n+s+P6Cu33CRQ2cobmDPBTunH2NIjliJTbL55SBIE+pWAaiESLhmf55dryB1yWcRebH/hknH9VHZU mAl90GBy2vQwCaxOJvLMuhb6VHF73GBVSZJbD3BtCyuXTUn+nSSqE+mg/pLZiK4Z8ywdN3DXfEolo 6OebMsuLQuxMLZAPM9OB4I8fLIOaHJz599d+b/tkI9b+L2aALid/EREhDPXC60ZfYwjryHsRSmARE /1+NOH3yw==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lMxcb-005s1p-Lv; Thu, 18 Mar 2021 18:43:49 +0000 Received: from mail-lf1-x133.google.com ([2a00:1450:4864:20::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lMxcU-005s0P-QX for linux-arm-kernel@lists.infradead.org; Thu, 18 Mar 2021 18:43:44 +0000 Received: by mail-lf1-x133.google.com with SMTP id o10so6163142lfb.9 for ; Thu, 18 Mar 2021 11:43:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nO1NtgEydXG2HLjdhqcJj5jPeQtrUPiYrY1ZDV7Qq/s=; b=iVhfN+7riOgr03gvFp6rabJN8XblDjHGtyOGptCHZxdhiECWH17xolvbVqxD61vi5I j7wFaX5OK16XDA5OTljEBtUkLE2p3wAIHOYdcH8ygbsif54rpWGXfnIWvKORxYc4UJ1w 6dpCNm4hA+O3GYVYuNboKJbPCS8Oh2iWIqDuNjVnnqHZcMpWEB+u61udXs5p4zIplHiH CBdgrX3qELlJwkMMudYSduN4JtzCQ0guTsDLtI6hfWhmcv5TSoKkA2uF2dne+wk64bzA vhgHY9WcBAhuoxiLklXUyWlxBSx7Duidr12ctcSGZeFqB3A/j6mB7xOZA+MdIuSjYEd1 X7hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nO1NtgEydXG2HLjdhqcJj5jPeQtrUPiYrY1ZDV7Qq/s=; b=UXsl7M3a26K1RRRrGwVxKdSuU4aG3hg8dc92h+0XB24XBvgR5cxJNxpNzbM1eaVKzr pYmDWq2bzEYQpj/4z9f7RBROfCXXSVaB48ScBlF7yWk5dNRY59iGBiTy1XYCjtZbqEoz KOWYjdaNE8a2JPOQJQXUAhWaaxN0uWfM906Igyl+VDke1fSKuRjH2Fw6TyQF0bgT8ZnU x1pwA+ERMUHmppzChJYDgGVSOb1nvNDPgDTLGqpBpTAy9WhndL2nHi1ENVX9+Gpg2yRa Cq0gpeZWR0LP9O3dFt8pKlJqXkSPeyhxz5L+85nysB47PwBBbyEgc79Sk9XKvugJC1qQ DG/Q== X-Gm-Message-State: AOAM533IuKGwWoqOj/5rS8AHydhxZOUVCQJymz81lH9VOFkFuzLi2xXK IFJjMvK2QinFlPABApFedBHUhb/qlTIC5eHmijaEpw== X-Google-Smtp-Source: ABdhPJwPMFefAwqyWlFWcoKbDZciOiKnXiRQmrMNGrG6rw2lNtQsSLGJF3SwnZ8fBikFCSYXYvEuLtpI1LrMEMs5+eI= X-Received: by 2002:ac2:532c:: with SMTP id f12mr6587813lfh.73.1616093021734; Thu, 18 Mar 2021 11:43:41 -0700 (PDT) MIME-Version: 1.0 References: <20210318171111.706303-1-samitolvanen@google.com> <20210318171111.706303-11-samitolvanen@google.com> In-Reply-To: <20210318171111.706303-11-samitolvanen@google.com> From: Nick Desaulniers Date: Thu, 18 Mar 2021 11:43:29 -0700 Message-ID: Subject: Re: [PATCH v2 10/17] lkdtm: use __va_function To: Sami Tolvanen Cc: Kees Cook , Nathan Chancellor , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , bpf , linux-hardening@vger.kernel.org, linux-arch , Linux ARM , Linux Kbuild mailing list , PCI , LKML X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210318_184342_992530_C6CE66A4 X-CRM114-Status: GOOD ( 20.86 ) 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 Thu, Mar 18, 2021 at 10:11 AM Sami Tolvanen wrote: > > To ensure we take the actual address of a function in kernel text, use > __va_function. Otherwise, with CONFIG_CFI_CLANG, the compiler replaces > the address with a pointer to the CFI jump table, which is actually in > the module when compiled with CONFIG_LKDTM=m. Should patch 10 and 12 be reordered against one another? Otherwise it looks like 12 defines __va_function while 10 uses it? > > Signed-off-by: Sami Tolvanen > Acked-by: Kees Cook > --- > drivers/misc/lkdtm/usercopy.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c > index 109e8d4302c1..d173d6175c87 100644 > --- a/drivers/misc/lkdtm/usercopy.c > +++ b/drivers/misc/lkdtm/usercopy.c > @@ -314,7 +314,7 @@ void lkdtm_USERCOPY_KERNEL(void) > > pr_info("attempting bad copy_to_user from kernel text: %px\n", > vm_mmap); > - if (copy_to_user((void __user *)user_addr, vm_mmap, > + if (copy_to_user((void __user *)user_addr, __va_function(vm_mmap), > unconst + PAGE_SIZE)) { > pr_warn("copy_to_user failed, but lacked Oops\n"); > goto free_user; > -- > 2.31.0.291.g576ba9dcdaf-goog > -- Thanks, ~Nick Desaulniers _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel