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Date:   Fri, 3 Feb 2023 07:44:54 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     "Michael Kelley (LINUX)" <mikelley@microsoft.com>
Cc:     "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        KY Srinivasan <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] HV: hv_balloon: fix memory leak with using
 debugfs_lookup()
Message-ID: <Y9ytZo23CTV6AsCS@kroah.com>
References: <20230202140918.2289522-1-gregkh@linuxfoundation.org>
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On Fri, Feb 03, 2023 at 03:56:06AM +0000, Michael Kelley (LINUX) wrote:
> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Sent: Thursday, February 2, 2023 6:09 AM
> 
> > 
> > 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: "K. Y. Srinivasan" <kys@microsoft.com>
> > Cc: Haiyang Zhang <haiyangz@microsoft.com>
> > Cc: Wei Liu <wei.liu@kernel.org>
> > Cc: Dexuan Cui <decui@microsoft.com>
> > Cc: linux-hyperv@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> Add a Fixes: tag?  This hv_balloon debugfs code was added in v6.0,
> And I see that debugfs_lookup_and_remove() was also added in v6.0.
> 
> Fixes: d180e0a1be6c ("Drivers: hv: Create debugfs file with hyper-v balloon usage information")

Will do, thanks.

greg k-h