From patchwork Wed Sep 8 03:00:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12480047 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7A796C433EF for ; Wed, 8 Sep 2021 03:00:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3304761100 for ; Wed, 8 Sep 2021 03:00:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3304761100 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id CEA5C940055; Tue, 7 Sep 2021 23:00:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C9968940042; Tue, 7 Sep 2021 23:00:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BB031940055; Tue, 7 Sep 2021 23:00:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0163.hostedemail.com [216.40.44.163]) by kanga.kvack.org (Postfix) with ESMTP id AB871940042 for ; Tue, 7 Sep 2021 23:00:11 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 6E52E2D4C5 for ; Wed, 8 Sep 2021 03:00:11 +0000 (UTC) X-FDA: 78562902222.17.B34033C Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP id 05BF73000099 for ; Wed, 8 Sep 2021 03:00:10 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id EA9D261131; Wed, 8 Sep 2021 03:00:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1631070010; bh=wDr4SvlGnwGxrTiQgEK5imjf6xAeEw/MQGbfyTeS/UM=; h=Date:From:To:Subject:In-Reply-To:From; b=hDlULrqn/IaEfDvzoAw6i6YxTAxe1GvaVH9ZJmpKWbmAs8VuY86o4e9nBCgVI1XJU 9B9e9KfQH097kSvedvj/+j6mubUpCnJ8xSlApDlMz8B3sqr0qKX4so50580VmHeTDj f44oA91bQYQae39Cq/iJJCpcUkeuCeNjShC0QdBc= Date: Tue, 07 Sep 2021 20:00:09 -0700 From: Andrew Morton To: akpm@linux-foundation.org, hulkci@huawei.com, konishi.ryusuke@gmail.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, sunnanyong@huawei.com, torvalds@linux-foundation.org Subject: [patch 130/147] nilfs2: fix memory leak in nilfs_sysfs_create_device_group Message-ID: <20210908030009.rpqY6Lr_a%akpm@linux-foundation.org> In-Reply-To: <20210907195226.14b1d22a07c085b22968b933@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=hDlULrqn; spf=pass (imf03.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Stat-Signature: mhqfki1euatfegqbczjw6f5x74s7r3s7 X-Rspamd-Queue-Id: 05BF73000099 X-Rspamd-Server: rspam04 X-HE-Tag: 1631070010-418940 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Nanyong Sun Subject: nilfs2: fix memory leak in nilfs_sysfs_create_device_group 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: [<000000009d9e0ac4>] slab_alloc_node mm/slub.c:2972 [inline] [<000000009d9e0ac4>] slab_alloc mm/slub.c:2980 [inline] [<000000009d9e0ac4>] __kmalloc_track_caller+0x164/0x330 mm/slub.c:4644 [<00000000b1825477>] kstrdup+0x36/0x70 mm/util.c:60 [<00000000fa081499>] kstrdup_const+0x35/0x60 mm/util.c:83 [<0000000024d13570>] kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48 [<0000000024b69715>] kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 [<000000003fedac3d>] kobject_add_varg lib/kobject.c:384 [inline] [<000000003fedac3d>] kobject_init_and_add+0xc9/0x150 lib/kobject.c:473 [<000000002795bd99>] nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986 [<00000000567fa12d>] init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637 [<00000000082e7458>] nilfs_fill_super fs/nilfs2/super.c:1046 [inline] [<00000000082e7458>] nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316 [<00000000adc3fd88>] legacy_get_tree+0x105/0x210 fs/fs_context.c:592 [<00000000a98c45b8>] vfs_get_tree+0x8e/0x2d0 fs/super.c:1498 [<00000000e96282d3>] do_new_mount fs/namespace.c:2905 [inline] [<00000000e96282d3>] path_mount+0xf9b/0x1990 fs/namespace.c:3235 [<000000003d2eb1b0>] do_mount+0xea/0x100 fs/namespace.c:3248 [<00000000e1ce771a>] __do_sys_mount fs/namespace.c:3456 [inline] [<00000000e1ce771a>] __se_sys_mount fs/namespace.c:3433 [inline] [<00000000e1ce771a>] __x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433 [<000000007c7f81e8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<000000007c7f81e8>] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 [<00000000fd23ff06>] 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 --- fs/nilfs2/sysfs.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/fs/nilfs2/sysfs.c~nilfs2-fix-memory-leak-in-nilfs_sysfs_create_device_group +++ a/fs/nilfs2/sysfs.c @@ -986,7 +986,7 @@ int nilfs_sysfs_create_device_group(stru 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) @@ -1023,9 +1023,7 @@ 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: