From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:24471 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726038AbgCHH6O (ORCPT ); Sun, 8 Mar 2020 03:58:14 -0400 Received: by mail-qv1-f72.google.com with SMTP id u5so4620297qvj.10 for ; Sat, 07 Mar 2020 23:58:11 -0800 (PST) Date: Sun, 8 Mar 2020 03:58:05 -0400 From: "Michael S. Tsirkin" Subject: Re: [PATCH] virtio_ring: Fix mem leak with vring_new_virtqueue() Message-ID: <20200308035751-mutt-send-email-mst@kernel.org> References: <20200224212643.30672-1-s-anna@ti.com> <0ace3a3b-cf2f-7977-5337-f74f530afbe1@ti.com> <1ce2bee4-64ed-f630-2695-8e8b9b8e27c1@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-remoteproc-owner@vger.kernel.org To: Suman Anna Cc: Jason Wang , Tiwei Bie , "David S. Miller" , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-remoteproc@vger.kernel.org List-ID: On Thu, Mar 05, 2020 at 06:27:53PM -0600, Suman Anna wrote: > On 2/25/20 9:13 PM, Jason Wang wrote: > > > > On 2020/2/26 上午12:51, Suman Anna wrote: > >> Hi Jason, > >> > >> On 2/24/20 11:39 PM, Jason Wang wrote: > >>> On 2020/2/25 上午5:26, Suman Anna wrote: > >>>> The functions vring_new_virtqueue() and __vring_new_virtqueue() are > >>>> used > >>>> with split rings, and any allocations within these functions are > >>>> managed > >>>> outside of the .we_own_ring flag. The commit cbeedb72b97a > >>>> ("virtio_ring: > >>>> allocate desc state for split ring separately") allocates the desc > >>>> state > >>>> within the __vring_new_virtqueue() but frees it only when the > >>>> .we_own_ring > >>>> flag is set. This leads to a memory leak when freeing such allocated > >>>> virtqueues with the vring_del_virtqueue() function. > >>>> > >>>> Fix this by moving the desc_state free code outside the flag and only > >>>> for split rings. Issue was discovered during testing with remoteproc > >>>> and virtio_rpmsg. > >>>> > >>>> Fixes: cbeedb72b97a ("virtio_ring: allocate desc state for split ring > >>>> separately") > >>>> Signed-off-by: Suman Anna > >>>> --- > >>>>    drivers/virtio/virtio_ring.c | 4 ++-- > >>>>    1 file changed, 2 insertions(+), 2 deletions(-) > >>>> > >>>> diff --git a/drivers/virtio/virtio_ring.c > >>>> b/drivers/virtio/virtio_ring.c > >>>> index 867c7ebd3f10..58b96baa8d48 100644 > >>>> --- a/drivers/virtio/virtio_ring.c > >>>> +++ b/drivers/virtio/virtio_ring.c > >>>> @@ -2203,10 +2203,10 @@ void vring_del_virtqueue(struct virtqueue *_vq) > >>>>                         vq->split.queue_size_in_bytes, > >>>>                         vq->split.vring.desc, > >>>>                         vq->split.queue_dma_addr); > >>>> - > >>>> -            kfree(vq->split.desc_state); > >>>>            } > >>>>        } > >>>> +    if (!vq->packed_ring) > >>>> +        kfree(vq->split.desc_state); > >>> Nitpick, it looks to me it would be more clear if we just free > >>> desc_state unconditionally here (and remove the kfree for packed above). > >> OK, are you sure you want that to be folded into this patch? It looks to > >> me a separate cleanup/consolidation patch, and packed desc_state does > >> not suffer this memleak, and need not be backported into stable kernels. > >> > >> regards > >> Suman > > > > > > Though it's just a small tweak, I'm fine for leaving it for future. > > > > So > > > > Acked-by: Jason Wang > > > > Mike, > Ping on this. I don't see the patch in -next yet. Can we get this into > the current -rc please? > > regards > Suman Yes will queue it shortly, thanks! From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] virtio_ring: Fix mem leak with vring_new_virtqueue() Date: Sun, 8 Mar 2020 03:58:05 -0400 Message-ID: <20200308035751-mutt-send-email-mst@kernel.org> References: <20200224212643.30672-1-s-anna@ti.com> <0ace3a3b-cf2f-7977-5337-f74f530afbe1@ti.com> <1ce2bee4-64ed-f630-2695-8e8b9b8e27c1@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Suman Anna Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, "David S. 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