Re: [PATCH 2/9] virtio_pci: use shared interrupts for virtqueues

[Jason Wang]

On 2017å02æ03æ 16:26, Christoph Hellwig wrote:
> On Fri, Feb 03, 2017 at 03:54:54PM +0800, Jason Wang wrote:
> > On 2017å01æ27æ 16:16, Christoph Hellwig wrote:
> > > +		snprintf(vp_dev->msix_names[i + 1],
> > > +			 sizeof(*vp_dev->msix_names), "%s-%s",
> > >    			 dev_name(&vp_dev->vdev.dev), names[i]);
> > >    		err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
> > > -				  vring_interrupt, 0,
> > > -				  vp_dev->msix_names[msix_vec],
> > > -				  vqs[i]);
> > > +				  vring_interrupt, IRQF_SHARED,
> > > +				  vp_dev->msix_names[i + 1], vqs[i]);
> > Do we need to check per_vq_vectors before dereferencing msix_names[i + 1] ?
> No, we need to allocate the array larger in that case as want proper
> names for the interrupts.

Consider the case of !per_vq_vectors, the size of msix_names is 2, but 
snprintf can do out of bound accessing here. (We name the msix shared by 
virtqueues with something like "%s-virtqueues" before the patch).

Thanks