[PATCH 1/2] vfio/fsl-mc: return -EFAULT if copy_to_user() fails

From: Dan Carpenter
Date: Fri Oct 23 2020 - 07:35:39 EST


The copy_to_user() function returns the number of bytes remaining to be
copied, but this code should return -EFAULT.

Fixes: df747bcd5b21 ("vfio/fsl-mc: Implement VFIO_DEVICE_GET_REGION_INFO ioctl call")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/vfio/fsl-mc/vfio_fsl_mc.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index 0113a980f974..21f22e3da11f 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -248,7 +248,9 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
info.size = vdev->regions[info.index].size;
info.flags = vdev->regions[info.index].flags;

- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
}
case VFIO_DEVICE_GET_IRQ_INFO:
{
@@ -267,7 +269,9 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
info.flags = VFIO_IRQ_INFO_EVENTFD;
info.count = 1;

- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
}
case VFIO_DEVICE_SET_IRQS:
{
--
2.28.0