From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87BEB63B8 for ; Mon, 20 Feb 2023 13:43:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA7DFC433EF; Mon, 20 Feb 2023 13:43:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676900621; bh=XaUjfARrtad1FCUZbMjgSgArRMcBlkpaMQOSEo4sKIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KBFNFAXqaFEYE9WA7CtGwDNlKVNDbDTq+p+ej6AFijc95L2hkj93q5U5JIJq9vtYq 5RZTZMxvIJwZeoQNaNu6lBy25LnyGdAGKNsmy8kUxh7vsCw/hWbBRtOp8kK7L2Dgb3 cVVTwoVQ8nrQfcJSrNiCdTRlkfui2kawm652Nxks= 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 4.19 87/89] kvm: initialize all of the kvm_debugregs structure before sending it to userspace Date: Mon, 20 Feb 2023 14:36:26 +0100 Message-Id: <20230220133556.242957174@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230220133553.066768704@linuxfoundation.org> References: <20230220133553.066768704@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -3637,12 +3637,11 @@ 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,