[PATCH AUTOSEL 4.14 024/105] media: mc-device.c: don't memset __user pointer contents

[Sasha Levin]

From: Hans Verkuil <hverkuil@xxxxxxxxx>

[ Upstream commit 518fa4e0e0da97ea2e17c95ab57647ce748a96e2 ]

You can't memset the contents of a __user pointer. Instead, call copy_to_user to
copy links.reserved (which is zeroed) to the user memory.

This fixes this sparse warning:

SPARSE:drivers/media/mc/mc-device.c drivers/media/mc/mc-device.c:521:16:  warning: incorrect type in argument 1 (different address spaces)

Fixes: f49308878d720 ("media: media_device_enum_links32: clean a reserved field")

Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Reviewed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/media/media-device.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index a6d56154fac7..4eb51a618fe1 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -486,8 +486,9 @@ static long media_device_enum_links32(struct media_device *mdev,
 	if (ret)
 		return ret;
 
-	memset(ulinks->reserved, 0, sizeof(ulinks->reserved));
-
+	if (copy_to_user(ulinks->reserved, links.reserved,
+			 sizeof(ulinks->reserved)))
+		return -EFAULT;
 	return 0;
 }
 
-- 
2.20.1