[PATCH v3 3/5] kernel: watch_queue: copy user-array safely

[Philipp Stanner]

Currently, there is no overflow-check with memdup_user().

Use the new function memdup_array_user() instead of memdup_user() for
duplicating the user-space array safely.

Suggested-by: David Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Zack Rusin <zackr@xxxxxxxxxx>
---
 kernel/watch_queue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index d0b6b390ee42..778b4056700f 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -331,7 +331,7 @@ long watch_queue_set_filter(struct pipe_inode_info *pipe,
 	    filter.__reserved != 0)
 		return -EINVAL;
 
-	tf = memdup_user(_filter->filters, filter.nr_filters * sizeof(*tf));
+	tf = memdup_array_user(_filter->filters, filter.nr_filters, sizeof(*tf));
 	if (IS_ERR(tf))
 		return PTR_ERR(tf);
 
-- 
2.41.0