| From 8e6d012f040c9ded4b553d9ec89dbc279ac5e43d Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 7 Sep 2021 20:00:09 -0700 |
| Subject: nilfs2: fix memory leak in nilfs_sysfs_create_device_group |
| |
| From: Nanyong Sun <sunnanyong@huawei.com> |
| |
| [ 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 <hulkci@huawei.com> |
| Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.com |
| Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> |
| Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 68e8d61e28dd..d2d8ea89937a 100644 |
| --- a/fs/nilfs2/sysfs.c |
| +++ b/fs/nilfs2/sysfs.c |
| @@ -986,7 +986,7 @@ 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) |
| @@ -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: |
| -- |
| 2.33.0 |
| |