On Tue, Mar 10, 2020 at 02:47:20PM -0400, Vivek Goyal wrote: > On Tue, Mar 10, 2020 at 07:12:25AM -0400, Michael S. Tsirkin wrote: > [..] > > > +static bool vp_get_shm_region(struct virtio_device *vdev, > > > + struct virtio_shm_region *region, u8 id) > > > +{ > > > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > > + struct pci_dev *pci_dev = vp_dev->pci_dev; > > > + u8 bar; > > > + u64 offset, len; > > > + phys_addr_t phys_addr; > > > + size_t bar_len; > > > + int ret; > > > + > > > + if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len)) { > > > + return false; > > > + } > > > + > > > + ret = pci_request_region(pci_dev, bar, "virtio-pci-shm"); > > > + if (ret < 0) { > > > + dev_err(&pci_dev->dev, "%s: failed to request BAR\n", > > > + __func__); > > > + return false; > > > + } > > > + > > > + phys_addr = pci_resource_start(pci_dev, bar); > > > + bar_len = pci_resource_len(pci_dev, bar); > > > + > > > + if (offset + len > bar_len) { > > > + dev_err(&pci_dev->dev, > > > + "%s: bar shorter than cap offset+len\n", > > > + __func__); > > > + return false; > > > + } > > > + > > > > Something wrong with indentation here. > > Will fix all indentation related issues in this patch. > > > Also as long as you are validating things, it's worth checking > > offset + len does not overflow. > > Something like addition of following lines? > > + if ((offset + len) < offset) { > + dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n", > + __func__); > + return false; > + } > > Vivek That should do it.