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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E258EC43218 for ; Sat, 27 Apr 2019 21:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AEF8A208C2 for ; Sat, 27 Apr 2019 21:49:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556401769; bh=ad4NRf2D1FTn7+5by/ebxnREERSQZJsRoAGBTwdZ7K4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=pKhpl9krA31wbbd3mWfI9WBUVy2ikyitK7GHQeteUyIJAvtSf+IspOVcQdgZtn27p xvec2DYdq6qdOiJumIS/Lec8txF5XIeU5PXCGcVL8V5kgEXgdDdxbGq47N5wZ+rWK6 2Mf6Mf5DIqVQl9mUeWH8HGNghMOH+Xim/VYFMYZo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726388AbfD0Vt2 (ORCPT ); Sat, 27 Apr 2019 17:49:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:54028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726088AbfD0Vt2 (ORCPT ); Sat, 27 Apr 2019 17:49:28 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CB39620645; Sat, 27 Apr 2019 21:49:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556401767; bh=ad4NRf2D1FTn7+5by/ebxnREERSQZJsRoAGBTwdZ7K4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dq89bU2UJRp3k78iGEbCoJWQNVPkrxfNzNex5TBzfb5CKbmQ8ebcusXSQS/4FEm4g Nwrm1da3E1DtofGW7FdXzw7ncTI09feAE8QR9ENn7DkNLHThOv+THrOGT27WutXD97 O9u7hApR9qV7Ae3sb24mah5W0Rf/BTT//XfZV520= Date: Sat, 27 Apr 2019 23:49:25 +0200 From: Greg KH To: Borislav Petkov Cc: PanBian , Mauro Carvalho Chehab , James Morse , linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: EDAC: Fix memory leak in creating CSROW object Message-ID: <20190427214925.GE16338@kroah.com> References: <1555554438-103953-1-git-send-email-bianpan2016@163.com> <20190418172548.GL27160@zn.tnic> <20190419003536.GA57795@bianpan2016@163.com> <20190419004516.GC559@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190419004516.GC559@zn.tnic> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 19, 2019 at 02:45:16AM +0200, Borislav Petkov wrote: > On Fri, Apr 19, 2019 at 08:35:36AM +0800, PanBian wrote: > > Yes, I see that. Because the loop start with (--i), there is no put > > operation for the device that fails to create. So, I think we cannot > > rule out the possibility of memory leak. > > Ok, so this is not something you trigger - you're basically staring at > the code? > > Well, there's something else questionable in that code which I asked > Greg about today but we didn't finish that conversation, let me CC him. > > So AFAIU, devices for which device_add() has returned success, > should be removed with their counterpart device_del(). > edac_create_csrow_objects(), however, does put_device() on those in the > "unwinding" loop. > > And for the case where device_add() fails, you should do put_device() to > it. I.e., what you're saying. > > So I think we need to figure what needs to be done when before fixing > this properly. > > Greg? How about this patch, I think it fixes up everything you need to do here, right? diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c index 464174685589..0fb2d1de6d0e 100644 --- a/drivers/edac/edac_mc_sysfs.c +++ b/drivers/edac/edac_mc_sysfs.c @@ -404,6 +404,8 @@ static inline int nr_pages_per_csrow(struct csrow_info *csrow) static int edac_create_csrow_object(struct mem_ctl_info *mci, struct csrow_info *csrow, int index) { + int retval; + csrow->dev.type = &csrow_attr_type; csrow->dev.groups = csrow_dev_groups; device_initialize(&csrow->dev); @@ -415,7 +417,10 @@ static int edac_create_csrow_object(struct mem_ctl_info *mci, edac_dbg(0, "creating (virtual) csrow node %s\n", dev_name(&csrow->dev)); - return device_add(&csrow->dev); + retval = device_add(&csrow->dev); + if (retval) + put_device(&csrow->dev); + return retval; } /* Create a CSROW object under specifed edac_mc_device */ @@ -649,6 +654,8 @@ static int edac_create_dimm_object(struct mem_ctl_info *mci, edac_dbg(0, "creating rank/dimm device %s\n", dev_name(&dimm->dev)); + if (err) + put_device(&dimm->dev); return err; } @@ -928,6 +935,7 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci, err = device_add(&mci->dev); if (err < 0) { edac_dbg(1, "failure: create device %s\n", dev_name(&mci->dev)); + put_device(mci->dev); goto out; }