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 02C72C433F5 for ; Tue, 18 Jan 2022 16:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347488AbiARQNb (ORCPT ); Tue, 18 Jan 2022 11:13:31 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:41534 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346878AbiARQLe (ORCPT ); Tue, 18 Jan 2022 11:11:34 -0500 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 sin.source.kernel.org (Postfix) with ESMTPS id 560B9CE1A47; Tue, 18 Jan 2022 16:11:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E1A4C340E0; Tue, 18 Jan 2022 16:11:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1642522290; bh=UYYUMo1mUrFFL/7scIcn9NFrEorA5XJbOgmC+sLMyaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yybq71osKvpqsHMa0dwRIey7vsFWc1m32qO1LPN4lE6j/xqaQEN/zMB8XAXglAcXZ 5p7mArqHSDrGNUNOKzgPtoqeyMKOE1uiT0LuWk/219I2F3L3GFnq7McPoR/Y4vBh9w LCORkPyumh3d5vJKkIcan1OF4Lw8/abPQJGCi7IQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gabriel Somlo , Johan Hovold Subject: [PATCH 5.16 20/28] firmware: qemu_fw_cfg: fix kobject leak in probe error path Date: Tue, 18 Jan 2022 17:06:15 +0100 Message-Id: <20220118160453.070650749@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118160452.384322748@linuxfoundation.org> References: <20220118160452.384322748@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold commit 47a1db8e797da01a1309bf42e0c0d771d4e4d4f3 upstream. An initialised kobject must be freed using kobject_put() to avoid leaking associated resources (e.g. the object name). Commit fe3c60684377 ("firmware: Fix a reference count leak.") "fixed" the leak in the first error path of the file registration helper but left the second one unchanged. This "fix" would however result in a NULL pointer dereference due to the release function also removing the never added entry from the fw_cfg_entry_cache list. This has now been addressed. Fix the remaining kobject leak by restoring the common error path and adding the missing kobject_put(). Fixes: 75f3e8e47f38 ("firmware: introduce sysfs driver for QEMU's fw_cfg device") Cc: stable@vger.kernel.org # 4.6 Cc: Gabriel Somlo Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20211201132528.30025-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/qemu_fw_cfg.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -603,15 +603,13 @@ static int fw_cfg_register_file(const st /* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */ err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype, fw_cfg_sel_ko, "%d", entry->select); - if (err) { - kobject_put(&entry->kobj); - return err; - } + if (err) + goto err_put_entry; /* add raw binary content access */ err = sysfs_create_bin_file(&entry->kobj, &fw_cfg_sysfs_attr_raw); if (err) - goto err_add_raw; + goto err_del_entry; /* try adding "/sys/firmware/qemu_fw_cfg/by_name/" symlink */ fw_cfg_build_symlink(fw_cfg_fname_kset, &entry->kobj, entry->name); @@ -620,9 +618,10 @@ static int fw_cfg_register_file(const st fw_cfg_sysfs_cache_enlist(entry); return 0; -err_add_raw: +err_del_entry: kobject_del(&entry->kobj); - kfree(entry); +err_put_entry: + kobject_put(&entry->kobj); return err; }