From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Ellerman Date: Fri, 29 Jun 2018 01:55:40 +0000 Subject: Re: [PATCH kernel v2 0/2] KVM: PPC: Check if IOMMU page is contained in the pinned physical page Message-Id: <877emiwe3n.fsf@concordia.ellerman.id.au> List-Id: References: <20180626055926.27703-1-aik@ozlabs.ru> In-Reply-To: <20180626055926.27703-1-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alexey Kardashevskiy , linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Alex Williamson , kvm-ppc@vger.kernel.org, David Gibson Alexey Kardashevskiy writes: > This is to improve page boundaries checking and should probably > be cc:stable. I came accross this while debugging nvlink2 passthrough > but the lack of checking might be exploited by the existing userspace. Do you really mean "exploited" ? As in there's a security issue? Your change log for patch 2 sort of suggests that but then says that without the fix you just hit an error in vfio code. So I'm not clear on what the exposure is. cheers From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 41H0994TWBzF1Q2 for ; Fri, 29 Jun 2018 11:55:41 +1000 (AEST) From: Michael Ellerman To: Alexey Kardashevskiy , linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Alex Williamson , kvm-ppc@vger.kernel.org, David Gibson Subject: Re: [PATCH kernel v2 0/2] KVM: PPC: Check if IOMMU page is contained in the pinned physical page In-Reply-To: <20180626055926.27703-1-aik@ozlabs.ru> References: <20180626055926.27703-1-aik@ozlabs.ru> Date: Fri, 29 Jun 2018 11:55:40 +1000 Message-ID: <877emiwe3n.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Alexey Kardashevskiy writes: > This is to improve page boundaries checking and should probably > be cc:stable. I came accross this while debugging nvlink2 passthrough > but the lack of checking might be exploited by the existing userspace. Do you really mean "exploited" ? As in there's a security issue? Your change log for patch 2 sort of suggests that but then says that without the fix you just hit an error in vfio code. So I'm not clear on what the exposure is. cheers