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 68FB7C433F5 for ; Wed, 1 Dec 2021 13:32:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349510AbhLANf4 (ORCPT ); Wed, 1 Dec 2021 08:35:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349541AbhLANfl (ORCPT ); Wed, 1 Dec 2021 08:35:41 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9A56C061748; Wed, 1 Dec 2021 05:32:20 -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 sin.source.kernel.org (Postfix) with ESMTPS id 1477BCE1DB6; Wed, 1 Dec 2021 13:32:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35F4FC53FD1; Wed, 1 Dec 2021 13:32:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638365537; bh=zbIAB0xAPmHrLVaWtGAiUDtaS268VPsxSnRQ1pw/suo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gRbHTxnTCb1a0XCCIt7q5yKJ0gI8CmE6HsDkKKBzjfJtBtZXwpxADr/2lgHPZjKtJ EApK+62hGbiEiR0OYxygV525zebiVIw1Ne9vrAkHS/hxdjYqmhJ3XpkVCGnm7gTuxX ZHUseGqnlTnb5v6HPiCWkCXScfYVcx8Z8HXvIWEMHZ3SZBiqot9s3FVqY8joinEnet 3wMgHlX6IK2SLIPdN24th2VjRTVUx+gIG9OfYtLUTWcou9ma3gjUfsrzW/1Y7lQLxs zcO9C7Cs775Qk8Y6goY2dH6SiroOFS8n4HztmOaUEisEaZOtj5DyrNHBIjkAMuAJmp cMFHTy+nD4tZg== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1msPiH-0007ry-VV; Wed, 01 Dec 2021 14:31:58 +0100 From: Johan Hovold To: Gabriel Somlo , "Michael S. Tsirkin" Cc: Greg Kroah-Hartman , Kees Cook , qemu-devel@nongnu.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH 2/4] firmware: qemu_fw_cfg: fix kobject leak in probe error path Date: Wed, 1 Dec 2021 14:25:26 +0100 Message-Id: <20211201132528.30025-3-johan@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211201132528.30025-1-johan@kernel.org> References: <20211201132528.30025-1-johan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/firmware/qemu_fw_cfg.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index a9c64ebfc49a..ccb7ed62452f 100644 --- 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 struct fw_cfg_file *f) /* 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 struct fw_cfg_file *f) 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; } -- 2.32.0