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 BF47AC25B08 for ; Mon, 15 Aug 2022 19:52:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240837AbiHOTwS (ORCPT ); Mon, 15 Aug 2022 15:52:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345447AbiHOTvM (ORCPT ); Mon, 15 Aug 2022 15:51:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99E0B73920; Mon, 15 Aug 2022 11:50:07 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 9EAB260C0B; Mon, 15 Aug 2022 18:50:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C782C433D7; Mon, 15 Aug 2022 18:50:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589406; bh=8XzudxK/GSx4m9rQfdc62GIvbtc4ybw1doK19hUJQ7I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UEji6HJ04i5hCnlTUfexXbGMQ2b/3Je23muWXSlyGNiAP3cyh4KJgZ7wdGJxMW0Ar XL4LWYOA1mN4vQA2+faIzNsrl7alMY/XSiwLzECoWLOm5hFD8DiT2F/4kaRiEVACe8 cg7xHZ39AOYpl+GjC18QEupdGyV6yb3e7qcvYLzg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Jim Mattson , Sasha Levin Subject: [PATCH 5.15 709/779] KVM: x86: Signal #GP, not -EPERM, on bad WRMSR(MCi_CTL/STATUS) Date: Mon, 15 Aug 2022 20:05:53 +0200 Message-Id: <20220815180407.739335099@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Christopherson [ Upstream commit 2368048bf5c2ec4b604ac3431564071e89a0bc71 ] Return '1', not '-1', when handling an illegal WRMSR to a MCi_CTL or MCi_STATUS MSR. The behavior of "all zeros' or "all ones" for CTL MSRs is architectural, as is the "only zeros" behavior for STATUS MSRs. I.e. the intent is to inject a #GP, not exit to userspace due to an unhandled emulation case. Returning '-1' gets interpreted as -EPERM up the stack and effecitvely kills the guest. Fixes: 890ca9aefa78 ("KVM: Add MCE support") Fixes: 9ffd986c6e4e ("KVM: X86: #GP when guest attempts to write MCi_STATUS register w/o 0") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Reviewed-by: Jim Mattson Link: https://lore.kernel.org/r/20220512222716.4112548-2-seanjc@google.com Signed-off-by: Sasha Levin --- arch/x86/kvm/x86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index dac2892d095c..f5b7a05530eb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3109,13 +3109,13 @@ static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info) */ if ((offset & 0x3) == 0 && data != 0 && (data | (1 << 10) | 1) != ~(u64)0) - return -1; + return 1; /* MCi_STATUS */ if (!msr_info->host_initiated && (offset & 0x3) == 1 && data != 0) { if (!can_set_mci_status(vcpu)) - return -1; + return 1; } vcpu->arch.mce_banks[offset] = data; -- 2.35.1