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 5BA62C433FE for ; Wed, 30 Nov 2022 18:53:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231518AbiK3SxV (ORCPT ); Wed, 30 Nov 2022 13:53:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231557AbiK3SxE (ORCPT ); Wed, 30 Nov 2022 13:53:04 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80E03275DE for ; Wed, 30 Nov 2022 10:53:03 -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 ams.source.kernel.org (Postfix) with ESMTPS id 2C721B81C9F for ; Wed, 30 Nov 2022 18:53:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EC80C433C1; Wed, 30 Nov 2022 18:53:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669834380; bh=/7nNmNLkVrG6cnl4XZM4dyEmfIA/rHGBXc7NZRApXoo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vwIm0LY+LrgX5CHkqhjNrQHHPSIpVjaVOIZMfAr6MTfII1qIuST7ljX98OCLOxr9u 1KyOlY7dMUxgCEj7KPaS6JRhWuwRDzOPLjk+9NCId+x2O+4rqI2wgLAUFypmnW+aYX yKAz5KMVRDS1yPqf0IvAMlMZKSVfJyiRrt5gCXWQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michal Luczaj , David Woodhouse , Sean Christopherson , stable@kernel.org, Paolo Bonzini Subject: [PATCH 6.0 205/289] KVM: x86/xen: Validate port number in SCHEDOP_poll Date: Wed, 30 Nov 2022 19:23:10 +0100 Message-Id: <20221130180548.767960200@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221130180544.105550592@linuxfoundation.org> References: <20221130180544.105550592@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: David Woodhouse commit 4ea9439fd537313f3381f0af4ebbf05e3f51a58c upstream. We shouldn't allow guests to poll on arbitrary port numbers off the end of the event channel table. Fixes: 1a65105a5aba ("KVM: x86/xen: handle PV spinlocks slowpath") [dwmw2: my bug though; the original version did check the validity as a side-effect of an idr_find() which I ripped out in refactoring.] Reported-by: Michal Luczaj Signed-off-by: David Woodhouse Reviewed-by: Sean Christopherson Cc: stable@kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/xen.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -954,6 +954,14 @@ static int kvm_xen_hypercall_complete_us return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result); } +static inline int max_evtchn_port(struct kvm *kvm) +{ + if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) + return EVTCHN_2L_NR_CHANNELS; + else + return COMPAT_EVTCHN_2L_NR_CHANNELS; +} + static bool wait_pending_event(struct kvm_vcpu *vcpu, int nr_ports, evtchn_port_t *ports) { @@ -1042,6 +1050,10 @@ static bool kvm_xen_schedop_poll(struct *r = -EFAULT; goto out; } + if (ports[i] >= max_evtchn_port(vcpu->kvm)) { + *r = -EINVAL; + goto out; + } } if (sched_poll.nr_ports == 1) @@ -1308,14 +1320,6 @@ handle_in_userspace: return 0; } -static inline int max_evtchn_port(struct kvm *kvm) -{ - if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) - return EVTCHN_2L_NR_CHANNELS; - else - return COMPAT_EVTCHN_2L_NR_CHANNELS; -} - static void kvm_xen_check_poller(struct kvm_vcpu *vcpu, int port) { int poll_evtchn = vcpu->arch.xen.poll_evtchn;