Commit b06346ef authored May 23, 2023 by Theodore Ts'o Committed by Greg Kroah-Hartman Jun 09, 2023

ext4: disallow ea_inodes with extended attributes



commit 2bc7e7c1a3bc9bd0cbf0f71006f6fe7ef24a00c2 upstream.

An ea_inode stores the value of an extended attribute; it can not have
extended attributes itself, or this will cause recursive nightmares.
Add a check in ext4_iget() to make sure this is the case.

Cc: stable@kernel.org
Reported-by:  <syzbot+e44749b6ba4d0434cd47@syzkaller.appspotmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230524034951.779531-4-tytso@mit.edu


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ec2a04f8

fs/ext4/inode.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -4909,6 +4909,9 @@ static const char check_igot_inode(struct inode inode, ext4_iget_flags flags)
		if (flags & EXT4_IGET_EA_INODE) {
		if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
		return "missing EA_INODE flag";
		if (ext4_test_inode_state(inode, EXT4_STATE_XATTR) \|\|
		EXT4_I(inode)->i_file_acl)
		return "ea_inode with extended attributes";
		} else {
		if ((EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
		return "unexpected EA_INODE flag";