2023-11-22 08:03:17

by Yaxiong Tian

Subject: [PATCH] thunderbolt:debugfs:Fix memory leak with using debugfs_lookup()

From: Yaxiong Tian <[email protected]>

As Greg said,When calling debugfs_lookup() the result must have dput()
called on it,otherwise the memory will leak over time.
So just call debugfs_lookup_and_remove() instead.

Fixes: d0f1e0c2a699 ("thunderbolt: Add support for receiver lane margining")
Signed-off-by: Yaxiong Tian <[email protected]>
---
drivers/thunderbolt/debugfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/debugfs.c b/drivers/thunderbolt/debugfs.c
index c9ddd49138d8..e324cd899719 100644
--- a/drivers/thunderbolt/debugfs.c
+++ b/drivers/thunderbolt/debugfs.c
@@ -959,7 +959,7 @@ static void margining_port_remove(struct tb_port *port)
snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
if (parent)
- debugfs_remove_recursive(debugfs_lookup("margining", parent));
+ debugfs_lookup_and_remove("margining", parent);

kfree(port->usb4->margining);
port->usb4->margining = NULL;
--
2.25.1

2023-11-27 10:59:24

by Mika Westerberg

Subject: Re: [PATCH] thunderbolt:debugfs:Fix memory leak with using debugfs_lookup()

On Wed, Nov 22, 2023 at 04:02:43PM +0800, Yaxiong Tian wrote:
> From: Yaxiong Tian <[email protected]>
>
> As Greg said,When calling debugfs_lookup() the result must have dput()
> called on it,otherwise the memory will leak over time.
> So just call debugfs_lookup_and_remove() instead.
>
> Fixes: d0f1e0c2a699 ("thunderbolt: Add support for receiver lane margining")
> Signed-off-by: Yaxiong Tian <[email protected]>

Slightly modified the commit log and applied to thunderbolt.git/fixes, thanks!