Commit 7e936b73 authored May 28, 2012 by Andreas Dilger Committed by Theodore Ts'o May 28, 2012

ext4: disallow hard-linked directory in ext4_lookup



A hard-linked directory to its parent can cause the VFS to deadlock,
and is a sign of a corrupted file system.  So detect this case in
ext4_lookup(), before the rmdir() lockup scenario can take place.

Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

parent 967ac8af

fs/ext4/namei.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -1330,6 +1330,12 @@ static struct dentry ext4_lookup(struct inode dir, struct dentry *dentry, stru
		EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
		return ERR_PTR(-EIO);
		}
		if (unlikely(ino == dir->i_ino)) {
		EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
		dentry->d_name.len,
		dentry->d_name.name);
		return ERR_PTR(-EIO);
		}
		inode = ext4_iget(dir->i_sb, ino);
		if (inode == ERR_PTR(-ESTALE)) {
		EXT4_ERROR_INODE(dir,