linux-kernel - Re: [PATCH v4] mtd: spi-nor: fix memory leak when using debugfs

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Message-ID: <f60870dee13900252e0b13fb2f5f05b5@walle.cc>
Date:   Wed, 08 Feb 2023 17:15:41 +0100
From:   Michael Walle <michael@...le.cc>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-kernel@...r.kernel.org,
        Tudor Ambarus <tudor.ambarus@...rochip.com>,
        Pratyush Yadav <pratyush@...nel.org>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        Vignesh Raghavendra <vigneshr@...com>,
        linux-mtd@...ts.infradead.org
Subject: Re: [PATCH v4] mtd: spi-nor: fix memory leak when using
 debugfs_lookup()

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@...rochip.com>
> Cc: Pratyush Yadav <pratyush@...nel.org>
> Cc: Michael Walle <michael@...le.cc>
> Cc: Miquel Raynal <miquel.raynal@...tlin.com>
> Cc: Richard Weinberger <richard@....at>
> Cc: Vignesh Raghavendra <vigneshr@...com>
> Cc: linux-mtd@...ts.infradead.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

Reviewed-by: Michael Walle <michael@...le.cc>

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.