linux-kernel - Re: [PATCH v3] mtd: spi-nor: fix memory leak when using debugfs

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Message-ID: <Y+PFreHoRVB+5J+1@kroah.com>
Date:   Wed, 8 Feb 2023 16:54:21 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Michael Walle <michael@...le.cc>
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 v3] mtd: spi-nor: fix memory leak when using
 debugfs_lookup()

On Wed, Feb 08, 2023 at 04:28:45PM +0100, Michael Walle wrote:
> > +static void __exit spi_nor_module_exit(void)
> > +{
> > +	spi_nor_debugfs_shutdown();
> > +	spi_mem_driver_unregister(&spi_nor_driver);
> 
> Hm, does the order matter here? I didn't test it, but this will
> lead to:
> 
> rootdir = debugfs_create_dir("spi-nor", NULL);
> nor->debugfs_root = debugfs_create_dir("spi0", rootdir);
> debugfs_remove(rootdir);
> debugfs_remove(nor->debugfs_root);
> 
> If that's ok, then this looks good.

It's ok as the last call to debugfs_remove() will just fail as that
dentry is long gone.  Not the nicest, so I'll reverse them and send out
a v4 now.

thanks,

greg k-h