From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net] vhost: correctly check the return value of translate_desc() in log_used() Date: Fri, 15 Feb 2019 16:59:56 -0500 Message-ID: <20190215165929-mutt-send-email-mst@kernel.org> References: <20190215075324.18891-1-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stephen@networkplumber.org To: Jason Wang Return-path: Content-Disposition: inline In-Reply-To: <20190215075324.18891-1-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Fri, Feb 15, 2019 at 03:53:24PM +0800, Jason Wang wrote: > When fail, translate_desc() returns negative value, otherwise the > number of iovs. So we should fail when the return value is negative > instead of a blindly check against zero. > > Reported-by: Stephen Hemminger > Fixes: cc5e71075947 ("vhost: log dirty page correctly") > Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin and I guess the log was backported to stable so we want this backported too. > --- > drivers/vhost/vhost.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 24a129fcdd61..a2e5dc7716e2 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -1788,7 +1788,7 @@ static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) > > ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, > len, iov, 64, VHOST_ACCESS_WO); > - if (ret) > + if (ret < 0) > return ret; > > for (i = 0; i < ret; i++) { > -- > 2.17.1