• Mikulas Patocka's avatar
    dm crypt: don't overallocate the integrity tag space · ff0c129d
    Mikulas Patocka authored
    bio_sectors() returns the value in the units of 512-byte sectors (no
    matter what the real sector size of the device).  dm-crypt multiplies
    bio_sectors() by on_disk_tag_size to calculate the space allocated for
    integrity tags.  If dm-crypt is running with sector size larger than
    512b, it allocates more data than is needed.
    
    Device Mapper trims the extra space when passing the bio to
    dm-integrity, so this bug didn't result in any visible misbehavior.
    But it must be fixed to avoid wasteful memory allocation for the block
    integrity payload.
    
    Fixes: ef43aa38 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
    Cc: stable@vger.kernel.org # 4.12+
    Reported-by: default avatarMilan Broz <mbroz@redhat.com>
    Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
    ff0c129d
dm-crypt.c 79.3 KB