09d85f8d89
The "fix_hmac" argument improves security of internal_hash and journal_mac: - the section number is mixed to the mac, so that an attacker can't copy sectors from one journal section to another journal section - the superblock is protected by journal_mac - a 16-byte salt stored in the superblock is mixed to the mac, so that the attacker can't detect that two disks have the same hmac key and also to disallow the attacker to move sectors from one disk to another Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reported-by: Daniel Glockner <dg@emlix.com> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> # ReST fix Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>