[PATCH v2] mnt_idmapping: Use kmemdup_array instead of kmemdup for multiple allocation

[Yu Jiaoliang <yujiaoliang@xxxxxxxx>]

Let the kememdup_array() take care about multiplication and possible
overflows.

v2:Add a new modification for reverse array.

Signed-off-by: Yu Jiaoliang <yujiaoliang@xxxxxxxx>
---
 fs/mnt_idmapping.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/mnt_idmapping.c b/fs/mnt_idmapping.c
index 3c60f1eaca61..79491663dbc0 100644
--- a/fs/mnt_idmapping.c
+++ b/fs/mnt_idmapping.c
@@ -228,15 +228,15 @@ static int copy_mnt_idmap(struct uid_gid_map *map_from,
 		return 0;
 	}
 
-	forward = kmemdup(map_from->forward,
-			  nr_extents * sizeof(struct uid_gid_extent),
-			  GFP_KERNEL_ACCOUNT);
+	forward = kmemdup_array(map_from->forward, nr_extents,
+				sizeof(struct uid_gid_extent),
+				GFP_KERNEL_ACCOUNT);
 	if (!forward)
 		return -ENOMEM;
 
-	reverse = kmemdup(map_from->reverse,
-			  nr_extents * sizeof(struct uid_gid_extent),
-			  GFP_KERNEL_ACCOUNT);
+	reverse = kmemdup_array(map_from->reverse, nr_extents,
+				sizeof(struct uid_gid_extent),
+				GFP_KERNEL_ACCOUNT);
 	if (!reverse) {
 		kfree(forward);
 		return -ENOMEM;
-- 
2.34.1