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Sun, 05 Feb 2023 14:27:37 -0800 (PST) Date: Sun, 5 Feb 2023 14:27:36 -0800 (PST) From: David Rientjes To: Greg Kroah-Hartman cc: linux-mm@kvack.org, Christoph Lameter , Pekka Enberg , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/slub: fix memory leak with using debugfs_lookup() In-Reply-To: <20230202142022.2300096-1-gregkh@linuxfoundation.org> Message-ID: References: <20230202142022.2300096-1-gregkh@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9961A40011 X-Stat-Signature: wm1cbdoasiwkr3tj96zcn6kkcttm98ht X-HE-Tag: 1675636059-566269 X-HE-Meta: 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 KD9ELbQi 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 2 Feb 2023, Greg Kroah-Hartman wrote: > 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: Christoph Lameter > Cc: Pekka Enberg > Cc: David Rientjes > Cc: Joonsoo Kim > Cc: Andrew Morton > Cc: Vlastimil Babka > Cc: Roman Gushchin > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Greg Kroah-Hartman Acked-by: David Rientjes