From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 80881C05027 for ; Wed, 8 Feb 2023 14:12:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EYDBoj0qHemRIDtQ5vGPKR5XaRR1sN0R6ItJL4mriHU=; b=SIvMkDwJw5iq+R RUdOpa/p7V/4INHBDKtw/K7RaCtsL29pJSIidGlmVBYqvayVvkU/KUCbfIwgfcYGoxmNaoESZF+f5 /oW2nvdPwxQPO7n+4lW+tqDEoZTFug6cNPNnu/HxwTi5k0AVvWuG00yOmIzGizzRECfpgLIVl5MoP /Wgn5OmUEFzGs8SKi2hgTPaJ6eRT2Cav/AfOLPYQB/hkAbE6JJVgd1UVhd3eCHNazUBTHXHSFg0Js q+ZIemTiYMCVBg1lIRmzLbNWCUd3H5IsONBJVv6L6bkZlUs8S51JjztU1dl11DOL4KTBNxuhjcmIk UKhNu2e7OLfXZ63ku/Bw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pPlBk-00FrA1-Er; Wed, 08 Feb 2023 14:12:44 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pPlBh-00Fr8P-Rm for linux-mtd@lists.infradead.org; Wed, 08 Feb 2023 14:12:43 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 67A1361554; Wed, 8 Feb 2023 14:12:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B8AEC433D2; Wed, 8 Feb 2023 14:12:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675865560; bh=F3zZlNf5kXbKMWpgXrzQW6DGmA4bi8DUoSB2yopbhx0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QosyLxcPoq9hTssY+9afykwNt80UKmkh5DQvvey5c7cL7Sc9raGCbhvvk26VicMOF mmS+AQqEkieNOAQ8wYaPAu4Ijts2IpCbk8S6Y/HBFl7D/E8kCiQHSwRZdyijx7ETl2 q48+OiWp26ZMWS2GGWnqjOnP2orwbcND03JorTCs= Date: Wed, 8 Feb 2023 15:12:32 +0100 From: Greg Kroah-Hartman To: Michael Walle Cc: linux-kernel@vger.kernel.org, Tudor Ambarus , Pratyush Yadav , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, stable Subject: Re: [PATCH v2] mtd: spi-nor: fix memory leak when using debugfs_lookup() Message-ID: References: <20230208125758.1515806-1-gregkh@linuxfoundation.org> <69fbf8b55dcb9c5c0a1a5d59b2248670@walle.cc> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <69fbf8b55dcb9c5c0a1a5d59b2248670@walle.cc> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230208_061241_969412_FCB4186B X-CRM114-Status: GOOD ( 20.89 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Wed, Feb 08, 2023 at 02:36:23PM +0100, Michael Walle wrote: > Am 2023-02-08 13:57, schrieb Greg Kroah-Hartman: > > When calling debugfs_lookup() the result must have dput() called on it, > > otherwise the memory will leak over time. > > > > Cc: Tudor Ambarus > > Cc: Pratyush Yadav > > Cc: Michael Walle > > Cc: Miquel Raynal > > Cc: Richard Weinberger > > Cc: Vignesh Raghavendra > > Cc: linux-mtd@lists.infradead.org > > Cc: stable > > Signed-off-by: Greg Kroah-Hartman > > --- > > v2: fix up to work when module is removed and added, making the fix > > much simpler. > > > > drivers/mtd/spi-nor/debugfs.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/mtd/spi-nor/debugfs.c > > b/drivers/mtd/spi-nor/debugfs.c > > index ff895f6758ea..af41fbc09a97 100644 > > --- a/drivers/mtd/spi-nor/debugfs.c > > +++ b/drivers/mtd/spi-nor/debugfs.c > > @@ -242,6 +242,7 @@ void spi_nor_debugfs_register(struct spi_nor *nor) > > > > d = debugfs_create_dir(dev_name(nor->dev), rootdir); > > nor->debugfs_root = d; > > + dput(rootdir); > > rootdir might either be the return value of debugfs_lookup() or > debugfs_create_dir(). dput() is probably wrong for the latter, > right? Also there is an early return, where the dput() is missing, > too. {sigh} Yeah, this is all wrong, sorry. Let me fix this up again, properly. And to do it properly, let's have the module remove the directory if it is unloaded, like a good module should :) greg k-h ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80487C64EC5 for ; Wed, 8 Feb 2023 14:13:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231377AbjBHONG (ORCPT ); Wed, 8 Feb 2023 09:13:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230434AbjBHONB (ORCPT ); Wed, 8 Feb 2023 09:13:01 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65F164617B for ; Wed, 8 Feb 2023 06:12:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 27DAEB81C76 for ; Wed, 8 Feb 2023 14:12:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B8AEC433D2; Wed, 8 Feb 2023 14:12:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675865560; bh=F3zZlNf5kXbKMWpgXrzQW6DGmA4bi8DUoSB2yopbhx0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QosyLxcPoq9hTssY+9afykwNt80UKmkh5DQvvey5c7cL7Sc9raGCbhvvk26VicMOF mmS+AQqEkieNOAQ8wYaPAu4Ijts2IpCbk8S6Y/HBFl7D/E8kCiQHSwRZdyijx7ETl2 q48+OiWp26ZMWS2GGWnqjOnP2orwbcND03JorTCs= Date: Wed, 8 Feb 2023 15:12:32 +0100 From: Greg Kroah-Hartman To: Michael Walle Cc: linux-kernel@vger.kernel.org, Tudor Ambarus , Pratyush Yadav , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, stable Subject: Re: [PATCH v2] mtd: spi-nor: fix memory leak when using debugfs_lookup() Message-ID: References: <20230208125758.1515806-1-gregkh@linuxfoundation.org> <69fbf8b55dcb9c5c0a1a5d59b2248670@walle.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <69fbf8b55dcb9c5c0a1a5d59b2248670@walle.cc> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 08, 2023 at 02:36:23PM +0100, Michael Walle wrote: > Am 2023-02-08 13:57, schrieb Greg Kroah-Hartman: > > When calling debugfs_lookup() the result must have dput() called on it, > > otherwise the memory will leak over time. > > > > Cc: Tudor Ambarus > > Cc: Pratyush Yadav > > Cc: Michael Walle > > Cc: Miquel Raynal > > Cc: Richard Weinberger > > Cc: Vignesh Raghavendra > > Cc: linux-mtd@lists.infradead.org > > Cc: stable > > Signed-off-by: Greg Kroah-Hartman > > --- > > v2: fix up to work when module is removed and added, making the fix > > much simpler. > > > > drivers/mtd/spi-nor/debugfs.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/mtd/spi-nor/debugfs.c > > b/drivers/mtd/spi-nor/debugfs.c > > index ff895f6758ea..af41fbc09a97 100644 > > --- a/drivers/mtd/spi-nor/debugfs.c > > +++ b/drivers/mtd/spi-nor/debugfs.c > > @@ -242,6 +242,7 @@ void spi_nor_debugfs_register(struct spi_nor *nor) > > > > d = debugfs_create_dir(dev_name(nor->dev), rootdir); > > nor->debugfs_root = d; > > + dput(rootdir); > > rootdir might either be the return value of debugfs_lookup() or > debugfs_create_dir(). dput() is probably wrong for the latter, > right? Also there is an early return, where the dput() is missing, > too. {sigh} Yeah, this is all wrong, sorry. Let me fix this up again, properly. And to do it properly, let's have the module remove the directory if it is unloaded, like a good module should :) greg k-h