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 A84ACC05027 for ; Mon, 20 Feb 2023 13:50:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232398AbjBTNuY (ORCPT ); Mon, 20 Feb 2023 08:50:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232320AbjBTNuX (ORCPT ); Mon, 20 Feb 2023 08:50:23 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 96A191E5CC for ; Mon, 20 Feb 2023 05:50:10 -0800 (PST) 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 3128060D41 for ; Mon, 20 Feb 2023 13:50:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D958C433EF; Mon, 20 Feb 2023 13:50:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676901009; bh=+iqTeL3cDJaa3hEzcRuZuEksB8evryCKe+Mu9Fp7Xdw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0fbNyegFgam+BHrbR+tYrgDekR0A8GqLy1C1rPYn9RHe00BMdMjT/iAnqkP+b2DmH QdW34t21oTn2RDCsNWpoYiKVIIY0zHI6bqAxZqCGPDyV0lkpJXYr76p3NcS0S3fcFZ qsM4aW3jdxHPPZyR2X0d2sOreZPBOVJ3XA89XKCU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , stable , Xingyuan Mo Subject: [PATCH 5.4 152/156] kvm: initialize all of the kvm_debugregs structure before sending it to userspace Date: Mon, 20 Feb 2023 14:36:36 +0100 Message-Id: <20230220133609.003326741@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230220133602.515342638@linuxfoundation.org> References: <20230220133602.515342638@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: stable@vger.kernel.org From: Greg Kroah-Hartman commit 2c10b61421a28e95a46ab489fd56c0f442ff6952 upstream. When calling the KVM_GET_DEBUGREGS ioctl, on some configurations, there might be some unitialized portions of the kvm_debugregs structure that could be copied to userspace. Prevent this as is done in the other kvm ioctls, by setting the whole structure to 0 before copying anything into it. Bonus is that this reduces the lines of code as the explicit flag setting and reserved space zeroing out can be removed. Cc: Sean Christopherson Cc: Paolo Bonzini Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: Cc: "H. Peter Anvin" Cc: stable Reported-by: Xingyuan Mo Signed-off-by: Greg Kroah-Hartman Message-Id: <20230214103304.3689213-1-gregkh@linuxfoundation.org> Tested-by: Xingyuan Mo Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3948,12 +3948,11 @@ static void kvm_vcpu_ioctl_x86_get_debug { unsigned long val; + memset(dbgregs, 0, sizeof(*dbgregs)); memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db)); kvm_get_dr(vcpu, 6, &val); dbgregs->dr6 = val; dbgregs->dr7 = vcpu->arch.dr7; - dbgregs->flags = 0; - memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved)); } static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,