From patchwork Tue Jan 18 16:05:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 533522 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 334C4C433EF for ; Tue, 18 Jan 2022 16:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346725AbiARQIl (ORCPT ); Tue, 18 Jan 2022 11:08:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346414AbiARQIR (ORCPT ); Tue, 18 Jan 2022 11:08:17 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BFFDC061762; Tue, 18 Jan 2022 08:07:51 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 0B49C612D5; Tue, 18 Jan 2022 16:07:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF47DC00446; Tue, 18 Jan 2022 16:07:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1642522070; bh=UYYUMo1mUrFFL/7scIcn9NFrEorA5XJbOgmC+sLMyaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fxjLqzUvvDnkXU2+Yn6yAA+bnu34tE3u9Jd58wRIYXACjzCtLKz/X3GhoyGqEDoKS ZHP5As6iObcwf4wTjM6ygAVgpquDaZ9p48r/Er7fgvWaR3IFfsbZ+YN4wrvrTTuOg1 iCx5M0YnCgIk8Scjte6zhTVR8Obg+0swee/3d7eo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gabriel Somlo , Johan Hovold Subject: [PATCH 5.10 15/23] firmware: qemu_fw_cfg: fix kobject leak in probe error path Date: Tue, 18 Jan 2022 17:05:55 +0100 Message-Id: <20220118160451.753639278@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118160451.233828401@linuxfoundation.org> References: <20220118160451.233828401@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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; }