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

From: Dan Carpenter <dan.carpenter@oracle.com>
To: Diana Craciun <diana.craciun@oss.nxp.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Bharat Bhushan <Bharat.Bhushan@nxp.com>,
	Eric Auger <eric.auger@redhat.com>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH 1/2] vfio/fsl-mc: return -EFAULT if copy_to_user() fails
Date: Fri, 23 Oct 2020 14:34:50 +0300	[thread overview]
Message-ID: <20201023113450.GH282278@mwanda> (raw)

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@oracle.com>
---
 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

