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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 A64D2C433B4 for ; Mon, 12 Apr 2021 20:05:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8838A61249 for ; Mon, 12 Apr 2021 20:05:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245535AbhDLUFc (ORCPT ); Mon, 12 Apr 2021 16:05:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237103AbhDLUFb (ORCPT ); Mon, 12 Apr 2021 16:05:31 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36BCEC061756 for ; Mon, 12 Apr 2021 13:05:12 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id c17so9902487pfn.6 for ; Mon, 12 Apr 2021 13:05:12 -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=b0X8UQmzynZRI2M2txUleBEJT6AR9mJ+eoj3Z51kuHU=; b=nBtlU4Rb7o9zyMaVMcSZGyXsI0l6Ob3HXSHGVpZvkZ3zFgFWq0/NJEElLOMw3Xlpb2 BjuO1oEuyXqCOp9M/gjo0vbh0WW/7R40IVD8qvTRe1FAnjajizUZ2DY7mTpCNSTbpJRn ZXMw+N7p6I+Ytjhg6Wu8mP0bQn2Gm2/02mwlU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=b0X8UQmzynZRI2M2txUleBEJT6AR9mJ+eoj3Z51kuHU=; b=DJuWFi3O19xSDLRBUN2zvfNHMmp7Oy6J/q7gxWHMZWY+5dmFDvTQUmzZS2plBUElHP XzH/wscuoN0aG1o5riYb7bbygYBxokCdznVHwYC4kLCqEIMdugCTgy4S4DAewYw9vK5R imnwl7gW2dTQAMCMa19Fs8Rl/gE2p419yHxupJ6nfJyQKGttxzb2rEAwcbnUSbC7p1q6 LaqI0k+g2FUyy/DTkQwsx5AD6mzfzBYHbx9CArqXPNcgSoFobLGtIuKi0+kpqES2XaGW Oh6jShJT6kukfqdVwzBYwMPNUDeSZjosAl8z7fvLIG6E4zrGa5+5yio7QsTfLRRdN+2Z Q2JA== X-Gm-Message-State: AOAM530bQY4nymJQrvya73Gr0jDkNxVP0wyL19I4SIDFQ/mbrpMNJvvX l3HxYV80470hH0ZyN8nWdcpLQw== X-Google-Smtp-Source: ABdhPJwszblN5Q3JOfsPdSz5uCW7RjGtWmnvwb5YU5xE0BVn8qVibyaZZS0RNX4nGehCNkiv9jdepg== X-Received: by 2002:a65:4985:: with SMTP id r5mr28411591pgs.65.1618257911612; Mon, 12 Apr 2021 13:05:11 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t23sm244439pju.15.2021.04.12.13.05.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Apr 2021 13:05:10 -0700 (PDT) Date: Mon, 12 Apr 2021 13:05:09 -0700 From: Kees Cook To: Peter Zijlstra Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, x86@kernel.org, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, chris@chris-wilson.co.uk, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, hch@lst.de Subject: Re: [PATCH 4/7] mm: Introduce verify_page_range() Message-ID: <202104121302.57D7EF8@keescook> References: <20210412080012.357146277@infradead.org> <20210412080611.769864829@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210412080611.769864829@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 12, 2021 at 10:00:16AM +0200, Peter Zijlstra wrote: > +struct vpr_data { > + int (*fn)(pte_t pte, unsigned long addr, void *data); > + void *data; > +}; Eeerg. This is likely to become an attack target itself. Stored function pointer with stored (3rd) argument. This doesn't seem needed: only DRM uses it, and that's for error reporting. I'd rather plumb back errors in a way to not have to add another place in the kernel where we do func+arg stored calling. -- Kees Cook