[PATCH 6.2 0628/1001] trace/blktrace: fix memory leak with using debugfs_lookup()

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 83e8864fee26f63a7435e941b7c36a20fd6fe93e ]

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: linux-block@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-trace-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Link: https://lore.kernel.org/r/20230202141956.2299521-1-gregkh@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 kernel/trace/blktrace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 918a7d12df8ff..5743be5594153 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -320,8 +320,8 @@ static void blk_trace_free(struct request_queue *q, struct blk_trace *bt)
 	 * under 'q->debugfs_dir', thus lookup and remove them.
 	 */
 	if (!bt->dir) {
-		debugfs_remove(debugfs_lookup("dropped", q->debugfs_dir));
-		debugfs_remove(debugfs_lookup("msg", q->debugfs_dir));
+		debugfs_lookup_and_remove("dropped", q->debugfs_dir);
+		debugfs_lookup_and_remove("msg", q->debugfs_dir);
 	} else {
 		debugfs_remove(bt->dir);
 	}
-- 
2.39.2