On Sun, Feb 28, 2016 at 07:23:22AM -0600, Alex Williamson wrote: > On Thu, 25 Feb 2016 13:34:43 +0200 > "Michael S. Tsirkin" <[email protected]> wrote: > > > Calling return copy_to_user(...) in an ioctl will not > > do the right thing if there's a pagefault: > > copy_to_user returns the number of bytes not copied > > in this case. > > > > Fix up vfio to do > > if (copy_to_user(...)) > > return -EFAULT; > > > > everywhere. > > > > Reported-by: Dan Carpenter <[email protected]> > > Cc: [email protected] > > Signed-off-by: Michael S. Tsirkin <[email protected]> > > --- > > drivers/vfio/pci/vfio_pci.c | 9 ++++++--- > > drivers/vfio/platform/vfio_platform_common.c | 9 ++++++--- > > drivers/vfio/vfio_iommu_type1.c | 6 ++++-- > > 3 files changed, 16 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > > index 2760a7b..27a727a 100644 > > --- a/drivers/vfio/pci/vfio_pci.c > > +++ b/drivers/vfio/pci/vfio_pci.c > > @@ -446,7 +446,8 @@ static long vfio_pci_ioctl(void *device_data, > > info.num_regions = VFIO_PCI_NUM_REGIONS; > > info.num_irqs = VFIO_PCI_NUM_IRQS; > > > > - return copy_to_user((void __user *)arg, &info, minsz); > > + if (copy_to_user((void __user *)arg, &info, minsz)) > > + return -EFAULT; > > Ok, but where do we return 0 on success now?
Ouch. Thanks for pointing this out. Fixed in v2. -- MST
