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 6714DC3DA79 for ; Sat, 24 Dec 2022 01:39:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236492AbiLXBjr (ORCPT ); Fri, 23 Dec 2022 20:39:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236844AbiLXBin (ORCPT ); Fri, 23 Dec 2022 20:38:43 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D774D537DD; Fri, 23 Dec 2022 17:32:52 -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 E445EB8219D; Sat, 24 Dec 2022 01:32:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F072AC433D2; Sat, 24 Dec 2022 01:32:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671845555; bh=S/Rtcz4coVc2hgywIDhJMtKqrsU0w4nY+4mPqpCK7jw=; h=From:To:Cc:Subject:Date:From; b=C9QXw/7aEf1bFRYl3kmwZH516gjYpl5fb7rr7Nb/eznIYaQzrA/ewl4onHeROAxmu dggEHuQcbr2yaH2zeAUlew9DB68MiD49fyHFpu3ptqDAUDD6nwplhxnIA6Nh8+SBFi XK55DzZx5ZVnX0woaNYMoK8yf5TUIrkgL6BSahXy8FDqYGpxSQnYzANqZooiq1jxZy Nj6j+eng5QuZVCEPc1Cae9WQBC/uxlhSpvtAhftJdfN3P0kVhFtf9vw6+OrGSiV5pU JNvcsfU6m/j5x0MVbE8/kRpCRFz62XukWxzuaAlrETQyOuJa2xAvaNw520IS3BpuJB lEb10vJGAJdvQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yang Yingliang , Luben Tuikov , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 5.4 1/7] kset: fix memory leak when kset_register() returns error Date: Fri, 23 Dec 2022 20:32:27 -0500 Message-Id: <20221224013233.393537-1-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yang Yingliang [ Upstream commit 1662cea4623f75d8251adf07370bbaa958f0355d ] Inject fault while loading module, kset_register() may fail. If it fails, the kset.kobj.name allocated by kobject_set_name() which must be called before a call to kset_register() may be leaked, since refcount of kobj was set in kset_init(). To mitigate this, we free the name in kset_register() when an error is encountered, i.e. when kset_register() returns an error. A kset may be embedded in a larger structure which may be dynamically allocated in callers, it needs to be freed in ktype.release() or error path in callers, in this case, we can not call kset_put() in kset_register(), or it will cause double free, so just call kfree_const() to free the name and set it to NULL to avoid accessing bad pointer in callers. With this fix, the callers don't need care about freeing the name and may call kset_put() if kset_register() fails. Suggested-by: Luben Tuikov Signed-off-by: Yang Yingliang Reviewed-by: Link: https://lore.kernel.org/r/20221025071549.1280528-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- lib/kobject.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/kobject.c b/lib/kobject.c index 0c6d17503a11..3ce572d7c26d 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -869,6 +869,9 @@ EXPORT_SYMBOL_GPL(kobj_sysfs_ops); /** * kset_register() - Initialize and add a kset. * @k: kset. + * + * NOTE: On error, the kset.kobj.name allocated by() kobj_set_name() + * is freed, it can not be used any more. */ int kset_register(struct kset *k) { @@ -879,8 +882,12 @@ int kset_register(struct kset *k) kset_init(k); err = kobject_add_internal(&k->kobj); - if (err) + if (err) { + kfree_const(k->kobj.name); + /* Set it to NULL to avoid accessing bad pointer in callers. */ + k->kobj.name = NULL; return err; + } kobject_uevent(&k->kobj, KOBJ_ADD); return 0; } -- 2.35.1