From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id i1EsIUBAGVtjYAAAmS7hNA ; Thu, 07 Jun 2018 14:25:22 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id C703A6089E; Thu, 7 Jun 2018 14:25:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id D399D6063F; Thu, 7 Jun 2018 14:25:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D399D6063F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933310AbeFGOV4 (ORCPT + 25 others); Thu, 7 Jun 2018 10:21:56 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39435 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933071AbeFGOJK (ORCPT ); Thu, 7 Jun 2018 10:09:10 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbA-0005hO-8K; Thu, 07 Jun 2018 15:09:08 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb9-00036J-5Q; Thu, 07 Jun 2018 15:09:07 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "NCSC Security" , "Will Deacon" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 270/410] arm64: __show_regs: Only resolve kernel symbols when running at EL1 In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit a06f818a70de21b4b3b4186816094208fc7accf9 upstream. __show_regs pretty prints PC and LR by attempting to map them to kernel function names to improve the utility of crash reports. Unfortunately, this mapping is applied even when the pt_regs corresponds to user mode, resulting in a KASLR oracle. Avoid this issue by only looking up the function symbols when the register state indicates that we're actually running at EL1. Reported-by: NCSC Security Signed-off-by: Will Deacon [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- arch/arm64/kernel/process.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -197,8 +197,15 @@ void __show_regs(struct pt_regs *regs) } show_regs_print_info(KERN_DEFAULT); - printk("pc : %pS\n", (void *)regs->pc); - printk("lr : %pS\n", (void *)lr); + + if (!user_mode(regs)) { + printk("pc : %pS\n", (void *)regs->pc); + printk("lr : %pS\n", (void *)lr); + } else { + printk("pc : %016llx\n", regs->pc); + printk("lr : %016llx\n", lr); + } + printk("sp : %016llx pstate : %08llx\n", sp, regs->pstate); for (i = top_reg; i >= 0; i--) { printk("x%-2d: %016llx ", i, regs->regs[i]);