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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT 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 CDEABC43219 for ; Tue, 30 Apr 2019 14:56:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BFC920652 for ; Tue, 30 Apr 2019 14:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726563AbfD3O4P (ORCPT ); Tue, 30 Apr 2019 10:56:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:56398 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726053AbfD3O4O (ORCPT ); Tue, 30 Apr 2019 10:56:14 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 9FA9AABE1; Tue, 30 Apr 2019 14:56:13 +0000 (UTC) Date: Tue, 30 Apr 2019 16:56:13 +0200 From: Petr Mladek To: "Tobin C. Harding" Cc: Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Greg Kroah-Hartman , Joe Lawrence , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] livepatch: Fix kobject memleak Message-ID: <20190430145613.7tokgyqjsuxlyh2g@pathway.suse.cz> References: <20190430001534.26246-1-tobin@kernel.org> <20190430001534.26246-2-tobin@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190430001534.26246-2-tobin@kernel.org> User-Agent: NeoMutt/20170912 (1.9.0) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2019-04-30 10:15:33, Tobin C. Harding wrote: > Currently error return from kobject_init_and_add() is not followed by a > call to kobject_put(). This means there is a memory leak. I see, the ref count is always initialized to 1 via: + kobject_init_and_add() + kobject_init() + kobject_init_internal() + kref_init() > Signed-off-by: Tobin C. Harding > --- > kernel/livepatch/core.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c > index eb0ee10a1981..98a7bec41faa 100644 > --- a/kernel/livepatch/core.c > +++ b/kernel/livepatch/core.c > @@ -727,7 +727,9 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func) > ret = kobject_init_and_add(&func->kobj, &klp_ktype_func, > &obj->kobj, "%s,%lu", func->old_name, > func->old_sympos ? func->old_sympos : 1); > - if (!ret) > + if (ret) > + kobject_put(&func->kobj); > + else > func->kobj_added = true; We could actually get rid of the custom kobj_added. Intead, we could check for kobj->state_initialized in the various klp_free* functions. Best Regards, Petr