Re: [PATCH v4] mtd: spi-nor: fix memory leak when using debugfs_lookup()

From: Michael Walle
Date: Wed Feb 08 2023 - 11:15:48 EST


Am 2023-02-08 17:02, schrieb Greg Kroah-Hartman:
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To solve this, remove the
lookup and create the directory on the first device found, and then
remove it when the module is unloaded.

Cc: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Cc: Pratyush Yadav <pratyush@xxxxxxxxxx>
Cc: Michael Walle <michael@xxxxxxxx>
Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Vignesh Raghavendra <vigneshr@xxxxxx>
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Reviewed-by: Michael Walle <michael@xxxxxxxx>

one nit below I didn't notice earlier, no need to send a new
patch version just for that.

..

+void spi_nor_debugfs_shutdown(void)
+{
+ if (rootdir)
+ debugfs_remove(rootdir);

debugfs_remove() already has a check for NULL.