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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1B676CD6E77 for ; Thu, 4 Jun 2026 16:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9orPrlUBfpDOI7jIo4bTJeWXXTVxhyM5Awxa0kulX4U=; b=P+Zw15nLYrd5OjlAb4qeUypA5s a000pehFGwssNNwr1eoKFZFm3qm7//LkzkJyykDhOkrU8Ws0/P32tuxsEq8gheJKpzFaq751bPsod XfwokrA7GQojdIXPU0iA8PRUIsQF5Bo1mL0e8z3ikPoNXYXmaIPfrQZLjx8lfQ1onmVFZT8opRgSm f+9OZ6dZWaZZWxY3oiy4hL9OmYXOlbaa2Ew8atykE2+NGUpQ6w5yKu8TH1BSoTyidGprH9vh98FdC 107/sP2FG4zRYEH60E7SSUXbXc7WXnUi65kMDfW0fvSNe+rrernihgWQedG6xPZ3OHnxgMciW/oYS q5KlEgRA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wVBGy-0000000H6aX-2l1D; Thu, 04 Jun 2026 16:50:24 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wVBGu-0000000H6Zj-3Wgk for linux-arm-kernel@lists.infradead.org; Thu, 04 Jun 2026 16:50:23 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B09104973; Thu, 4 Jun 2026 09:50:14 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 69B6A3F7D8; Thu, 4 Jun 2026 09:50:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780591819; bh=38JUf3SZ3VZqsjB6ynqgMt4h1xyvY4kOLChEDF6u4d8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=s9dQ6haN/Phb4x7EJ9nXX4Ifq3IDaQ6kHbMraTI54HI8i1ea/p2XV+NUMIvr4+DsI kV8Cwns9sWiYe2i+9JVDFs5JS4LLzzfPD/NLHnfYe88SopVvS5wDynFR6tg9lnoIWl F9TIr62X0u7ngaCkrZ3JjstbwZ3B11i9jkTU+d1E= Date: Thu, 4 Jun 2026 17:50:15 +0100 From: Catalin Marinas To: Ard Biesheuvel Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, Ard Biesheuvel , Kevin Brodsky , Mark Brown , Marc Zyngier , stable@vger.kernel.org Subject: Re: [PATCH v2 4/5] KVM: arm64: Omit tag sync on stage-2 mappings of the zero page Message-ID: References: <20260604151151.150377-7-ardb+git@google.com> <20260604151151.150377-11-ardb+git@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260604151151.150377-11-ardb+git@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260604_095021_611749_C309DB4D X-CRM114-Status: GOOD ( 10.94 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jun 04, 2026 at 05:11:56PM +0200, Ard Biesheuvel wrote: > From: Ard Biesheuvel > > Commit > > f620d66af316 ("arm64: mte: Do not flag the zero page as PG_mte_tagged") > > removed the PG_mte_tagged flag from the zero page, but missed a KVM code > path that may set this flag on the zero page when it is used in a > stage-2 CoW mapping of anonymous memory. > > So disregard the zero page explicitly in sanitise_mte_tags(). > > Fixes: f620d66af316 ("arm64: mte: Do not flag the zero page as PG_mte_tagged") > Cc: # 5.10.x > Suggested-by: Catalin Marinas > Signed-off-by: Ard Biesheuvel Reviewed-by: Catalin Marinas