Re: [PATCH] ext4: fix leaking sysfs kobject after failed mount

Jan Kara
2020-09-24T13:55:42Z

On Tue 22-09-20 09:24:56, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> ext4_unregister_sysfs() only deletes the kobject. The reference to it
> needs to be put separately, like ext4_put_super() does.
>
> This addresses the syzbot report
> "memory leak in kobject_set_name_vargs (3)"
> (https://syzkaller.appspot.com/bug?extid=9f864abad79fae7c17e1).
>
> Reported-by: syzbot+9f864abad79fae7c17e1@syzkaller.appspotmail.com
> Fixes: 72ba74508b28 ("ext4: release sysfs kobject when failing to enable quotas on mount")
> Cc: stable@vger.kernel.org
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/ext4/super.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index ea425b49b345..41953b86ffe3 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4872,6 +4872,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
>
> failed_mount8:
> ext4_unregister_sysfs(sb);
> + kobject_put(&sbi->s_kobj);
> failed_mount7:
> ext4_unregister_li_request(sb);
> failed_mount6:
>
> base-commit: ba4f184e126b751d1bffad5897f263108befc780
> --
> 2.28.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR