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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 52206C4332F for ; Fri, 24 Sep 2021 13:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CC2960EE7 for ; Fri, 24 Sep 2021 13:10:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346826AbhIXNL6 (ORCPT ); Fri, 24 Sep 2021 09:11:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:37286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344878AbhIXNJ5 (ORCPT ); Fri, 24 Sep 2021 09:09:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B12F5613A4; Fri, 24 Sep 2021 12:57:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632488269; bh=zcLVKtHfl+HNekCVI7FoiBZzy7epYedJzAoamNzdPQU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mGkimOrBHMo5MwNQ8djciJ4JcVGtGm1wsqkTfyyuIgIZ2uR436JLFDJ90vIyp+bOo QfHQjhpXSuEstFStSl1yiupwEXKaCP9jqA9N6Gj7kaa7kyYoAPRDsDmgziE+CFeTUG KND7Vsl90mLNQWgwFSr0wwJpHmBfFennJKjSa18A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Nanyong Sun , Ryusuke Konishi , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.10 49/63] nilfs2: fix memory leak in nilfs_sysfs_create_device_group Date: Fri, 24 Sep 2021 14:44:49 +0200 Message-Id: <20210924124335.960305360@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210924124334.228235870@linuxfoundation.org> References: <20210924124334.228235870@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: stable@vger.kernel.org From: Nanyong Sun [ Upstream commit 5f5dec07aca7067216ed4c1342e464e7307a9197 ] Patch series "nilfs2: fix incorrect usage of kobject". This patchset from Nanyong Sun fixes memory leak issues and a NULL pointer dereference issue caused by incorrect usage of kboject in nilfs2 sysfs implementation. This patch (of 6): Reported by syzkaller: BUG: memory leak unreferenced object 0xffff888100ca8988 (size 8): comm "syz-executor.1", pid 1930, jiffies 4294745569 (age 18.052s) hex dump (first 8 bytes): 6c 6f 6f 70 31 00 ff ff loop1... backtrace: kstrdup+0x36/0x70 mm/util.c:60 kstrdup_const+0x35/0x60 mm/util.c:83 kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48 kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xc9/0x150 lib/kobject.c:473 nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986 init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637 nilfs_fill_super fs/nilfs2/super.c:1046 [inline] nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316 legacy_get_tree+0x105/0x210 fs/fs_context.c:592 vfs_get_tree+0x8e/0x2d0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0xf9b/0x1990 fs/namespace.c:3235 do_mount+0xea/0x100 fs/namespace.c:3248 __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount fs/namespace.c:3433 [inline] __x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae If kobject_init_and_add return with error, then the cleanup of kobject is needed because memory may be allocated in kobject_init_and_add without freeing. And the place of cleanup_dev_kobject should use kobject_put to free the memory associated with the kobject. As the section "Kobject removal" of "Documentation/core-api/kobject.rst" says, kobject_del() just makes the kobject "invisible", but it is not cleaned up. And no more cleanup will do after cleanup_dev_kobject, so kobject_put is needed here. Link: https://lkml.kernel.org/r/1625651306-10829-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/1625651306-10829-2-git-send-email-konishi.ryusuke@gmail.com Reported-by: Hulk Robot Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.com Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/nilfs2/sysfs.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c index 9c6c0e2e5880..b6a48492fed2 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -999,7 +999,7 @@ int nilfs_sysfs_create_device_group(struct super_block *sb) err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL, "%s", sb->s_id); if (err) - goto free_dev_subgroups; + goto cleanup_dev_kobject; err = nilfs_sysfs_create_mounted_snapshots_group(nilfs); if (err) @@ -1036,9 +1036,7 @@ delete_mounted_snapshots_group: nilfs_sysfs_delete_mounted_snapshots_group(nilfs); cleanup_dev_kobject: - kobject_del(&nilfs->ns_dev_kobj); - -free_dev_subgroups: + kobject_put(&nilfs->ns_dev_kobj); kfree(nilfs->ns_dev_subgroups); failed_create_device_group: -- 2.33.0