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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 50431C433E0 for ; Tue, 26 Jan 2021 18:47:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F32722286 for ; Tue, 26 Jan 2021 18:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390444AbhAZRSk (ORCPT ); Tue, 26 Jan 2021 12:18:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:54752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389836AbhAZQhX (ORCPT ); Tue, 26 Jan 2021 11:37:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A940C22241; Tue, 26 Jan 2021 16:36:41 +0000 (UTC) Date: Tue, 26 Jan 2021 16:36:39 +0000 From: Catalin Marinas To: Vincenzo Frascino Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, stable@vger.kernel.org, Will Deacon , Mark Rutland Subject: Re: [PATCH] arm64: Fix kernel address detection of __is_lm_address() Message-ID: <20210126163638.GA3509@gaia> References: <20210126134056.45747-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210126134056.45747-1-vincenzo.frascino@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Jan 26, 2021 at 01:40:56PM +0000, Vincenzo Frascino wrote: > Currently, the __is_lm_address() check just masks out the top 12 bits > of the address, but if they are 0, it still yields a true result. > This has as a side effect that virt_addr_valid() returns true even for > invalid virtual addresses (e.g. 0x0). > > Fix the detection checking that it's actually a kernel address starting > at PAGE_OFFSET. > > Fixes: f4693c2716b35 ("arm64: mm: extend linear region for 52-bit VA configurations") > Cc: # 5.4.x Not sure what happened with the Fixes tag but that's definitely not what it fixes. The above is a 5.11 commit that preserves the semantics of an older commit. So it should be: Fixes: 68dd8ef32162 ("arm64: memory: Fix virt_addr_valid() using __is_lm_address()") The above also had a fix for another commit but no need to add two entries, we just fix the original fix: 14c127c957c1 ("arm64: mm: Flip kernel VA space"). Anyway, no need to repost, I can update the fixes tag myself. In terms of stable backports, it may be cleaner to backport 7bc1a0f9e176 ("arm64: mm: use single quantity to represent the PA to VA translation") which has a Fixes tag already but never made it to -stable. On top of this, we can backport Ard's latest f4693c2716b35 ("arm64: mm: extend linear region for 52-bit VA configurations"). I just tried these locally and the conflicts were fairly trivial. -- Catalin