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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C85BDCDB483 for ; Wed, 18 Oct 2023 05:20:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229575AbjJRFUb (ORCPT ); Wed, 18 Oct 2023 01:20:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbjJRFU3 (ORCPT ); Wed, 18 Oct 2023 01:20:29 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03C81BA; Tue, 17 Oct 2023 22:20:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697606428; x=1729142428; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=ljGA96pJdhn4htcQFUZHNLFUU0HFsDrmUML7iu2lJmM=; b=NkDGnyUEoN3R4PBGmK+1jisLWPwnhyVT95AKBftggPqC766zp9TH9Apw sfMqh2hbaJ1Zahas3TA7WlRBuTz+ubApQiWo7UPoHuQ1la/uhcFTMadUi oJ24oNrmwqctlO5457nqyHHB2Nr7A0Cqkh30tVJhX5QZxrE9AiF4yt4f4 GLPK8guQuRhh2z86ReowICCrxc08XKljjGFOYN7duajz4kizEzrnSAb2a X8qjymA4Xd2W+vB1dtgmY+c+LTJrem2Z0LVsXZ1cEd3m2hJeVyHLwfJMu c38W6dKtAhGpto9xwNBek4051n2RGpjEgxGp9nSBbZTyKmjle+47T+lPw w==; X-IronPort-AV: E=McAfee;i="6600,9927,10866"; a="371003324" X-IronPort-AV: E=Sophos;i="6.03,234,1694761200"; d="scan'208";a="371003324" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2023 22:20:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10866"; a="822291496" X-IronPort-AV: E=Sophos;i="6.03,234,1694761200"; d="scan'208";a="822291496" Received: from jysong-mobl1.amr.corp.intel.com (HELO [10.251.4.174]) ([10.251.4.174]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2023 22:20:26 -0700 Message-ID: <3133a1a5-58c0-4b31-89fe-e86ffa12a342@linux.intel.com> Date: Tue, 17 Oct 2023 22:20:25 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 03/10] kvmclock: Use free_decrypted_pages() Content-Language: en-US To: Rick Edgecombe , x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, kirill.shutemov@linux.intel.com, elena.reshetova@intel.com, isaku.yamahata@intel.com, seanjc@google.com, Michael Kelley , thomas.lendacky@amd.com, decui@microsoft.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , kvm@vger.kernel.org References: <20231017202505.340906-1-rick.p.edgecombe@intel.com> <20231017202505.340906-4-rick.p.edgecombe@intel.com> From: Kuppuswamy Sathyanarayanan In-Reply-To: <20231017202505.340906-4-rick.p.edgecombe@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 10/17/2023 1:24 PM, Rick Edgecombe wrote: > On TDX it is possible for the untrusted host to cause > set_memory_encrypted() or set_memory_decrypted() to fail such that an > error is returned and the resulting memory is shared. Callers need to take > care to handle these errors to avoid returning decrypted (shared) memory to > the page allocator, which could lead to functional or security issues. > > Kvmclock could free decrypted/shared pages if set_memory_decrypted() fails. > Use the recently added free_decrypted_pages() to avoid this. > > Cc: Paolo Bonzini > Cc: Wanpeng Li > Cc: Vitaly Kuznetsov > Cc: kvm@vger.kernel.org > Signed-off-by: Rick Edgecombe > --- Since it a fix, do you want to add Fixes tag? Otherwise, it looks good to me. Reviewed-by: Kuppuswamy Sathyanarayanan > arch/x86/kernel/kvmclock.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index fb8f52149be9..587b159c4e53 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -227,7 +227,7 @@ static void __init kvmclock_init_mem(void) > r = set_memory_decrypted((unsigned long) hvclock_mem, > 1UL << order); > if (r) { > - __free_pages(p, order); > + free_decrypted_pages((unsigned long)hvclock_mem, order); > hvclock_mem = NULL; > pr_warn("kvmclock: set_memory_decrypted() failed. Disabling\n"); > return; -- Sathyanarayanan Kuppuswamy Linux Kernel Developer