From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 9427F7D087 for ; Fri, 12 Oct 2018 10:39:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726788AbeJLSLd (ORCPT ); Fri, 12 Oct 2018 14:11:33 -0400 Received: from mx2.suse.de ([195.135.220.15]:49950 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726665AbeJLSLd (ORCPT ); Fri, 12 Oct 2018 14:11:33 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5F33EAD66; Fri, 12 Oct 2018 10:39:45 +0000 (UTC) Date: Fri, 12 Oct 2018 12:39:45 +0200 From: Petr Mladek To: Geert Uytterhoeven Cc: Andy Shevchenko , "Tobin C . Harding" , Andrew Morton , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/3] lib/vsprintf: Hash legacy clock addresses Message-ID: <20181012103944.vj3jwpodhq2cg2fu@pathway.suse.cz> References: <20181011084249.4520-1-geert+renesas@glider.be> <20181011084249.4520-3-geert+renesas@glider.be> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181011084249.4520-3-geert+renesas@glider.be> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Thu 2018-10-11 10:42:48, Geert Uytterhoeven wrote: > On platforms using the Common Clock Framework, "%pC" prints the clock's > name. On legacy platforms, it prints the unhashed clock's address, > potentially leaking sensitive information regarding the kernel layout in > memory. > > Avoid this leak by printing the hashed address instead. To distinguish > between clocks, a 32-bit unique identifier is as good as an actual > pointer value. > > Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") > Signed-off-by: Geert Uytterhoeven > Reviewed-by: Petr Mladek I have pushed this patch into printk.git, branch for-4.20-vsprintf-hash-fixes. Best Regards, Petr