Messages in this thread | | | Subject | Re: [patch 1/3 v2] vfio: signedness bug in vfio_config_do_rw() | From | Alex Williamson <> | Date | Thu, 28 Jun 2012 16:24:29 -0600 |
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On Thu, 2012-06-28 at 11:07 +0300, Dan Carpenter wrote: > The "count" variable needs to be signed here because we use it to store > negative error codes. > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > v2: Just declare count as signed. > > diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c > index a4f7321..2e00aa8 100644 > --- a/drivers/vfio/pci/vfio_pci_config.c > +++ b/drivers/vfio/pci/vfio_pci_config.c > @@ -1419,7 +1419,7 @@ void vfio_config_free(struct vfio_pci_device *vdev) > } > > static ssize_t vfio_config_do_rw(struct vfio_pci_device *vdev, char __user *buf, > - size_t count, loff_t *ppos, bool iswrite) > + ssize_t count, loff_t *ppos, bool iswrite) > { > struct pci_dev *pdev = vdev->pdev; > struct perm_bits *perm;
signed doesn't seem right for count since just below this chunk we do:
if (*ppos < 0 || *ppos + count > pdev->cfg_size) return -EFAULT;
So then we have to start testing for negative count. I've added a ssize_t variable for return that should clear things up. Thanks for the report!
Alex
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