From: Jan Kara jack@suse.cz
commit 85a37983ec69cc9fcd188bc37c4de15ee326355a upstream.
When UDF filesystem is corrupted, hidden system inodes can be linked into directory hierarchy which is an avenue for further serious corruption of the filesystem and kernel confusion as noticed by syzbot fuzzed images. Refuse to access system inodes linked into directory hierarchy and vice versa.
CC: stable@vger.kernel.org Reported-by: syzbot+38695a20b8addcbc1084@syzkaller.appspotmail.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/udf/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1885,8 +1885,13 @@ struct inode *__udf_iget(struct super_bl if (!inode) return ERR_PTR(-ENOMEM);
- if (!(inode->i_state & I_NEW)) + if (!(inode->i_state & I_NEW)) { + if (UDF_I(inode)->i_hidden != hidden_inode) { + iput(inode); + return ERR_PTR(-EFSCORRUPTED); + } return inode; + }
memcpy(&UDF_I(inode)->i_location, ino, sizeof(struct kernel_lb_addr)); err = udf_read_inode(inode, hidden_inode);