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 C2117C433F5 for ; Sat, 21 May 2022 13:59:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237802AbiEUN7H (ORCPT ); Sat, 21 May 2022 09:59:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233746AbiEUN7G (ORCPT ); Sat, 21 May 2022 09:59:06 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D73573EAB4 for ; Sat, 21 May 2022 06:59:05 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 97196B803F3 for ; Sat, 21 May 2022 13:59:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA3D4C385A5; Sat, 21 May 2022 13:59:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653141543; bh=jIreq4+KfGbX6xPr8Hj/cfgQatvnZbRpTaALkJ7AIgU=; h=Subject:To:Cc:From:Date:From; b=L2Hr+KCZKtqMf4FkG2X2byn1YtIp5YgqSNLRH9PCdg7JVB3SKU75nW4e+Bt0LW+e2 IKdrFUVgRuRWEXWvy/v9Wh0aQmxMsr0Gjrl9jSWlQAXXthXmVaA0Kb4SEX/S7D9lPT f379ieoF71x3kKF5hrC4OSZmpArBr3zosllJ0QH4= Subject: FAILED: patch "[PATCH] KVM: x86/mmu: fix NULL pointer dereference on guest INVPCID" failed to apply to 5.15-stable tree To: pbonzini@redhat.com, kangel@zju.edu.cn Cc: From: Date: Sat, 21 May 2022 15:58:56 +0200 Message-ID: <165314153685166@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9f46c187e2e680ecd9de7983e4d081c3391acc76 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 20 May 2022 13:48:11 -0400 Subject: [PATCH] KVM: x86/mmu: fix NULL pointer dereference on guest INVPCID With shadow paging enabled, the INVPCID instruction results in a call to kvm_mmu_invpcid_gva. If INVPCID is executed with CR0.PG=0, the invlpg callback is not set and the result is a NULL pointer dereference. Fix it trivially by checking for mmu->invlpg before every call. There are other possibilities: - check for CR0.PG, because KVM (like all Intel processors after P5) flushes guest TLB on CR0.PG changes so that INVPCID/INVLPG are a nop with paging disabled - check for EFER.LMA, because KVM syncs and flushes when switching MMU contexts outside of 64-bit mode All of these are tricky, go for the simple solution. This is CVE-2022-1789. Reported-by: Yongkang Jia Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 56ebc4fb7f91..45e1573f8f1d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5470,14 +5470,16 @@ void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) uint i; if (pcid == kvm_get_active_pcid(vcpu)) { - mmu->invlpg(vcpu, gva, mmu->root.hpa); + if (mmu->invlpg) + mmu->invlpg(vcpu, gva, mmu->root.hpa); tlb_flush = true; } for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { if (VALID_PAGE(mmu->prev_roots[i].hpa) && pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { - mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); + if (mmu->invlpg) + mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); tlb_flush = true; } }