On Sun, Dec 30, 2012 at 11:59:56AM -0500, Emily Williams wrote: > On Fri, Dec 28, 2012 at 10:04 AM, Arno Wagner <arno@xxxxxxxxxxx> wrote: > > > I wonder how fsck checks for a superblock. I still assume, that chances > > of > > > having encrypted data in the right block on disk looking like a correct > > > ext-superblock is next to zero. > > > > The ext2 superblock magic number seems to be 0xEF53. That is a bit > > short but still only gives something like 1 in 65536 probability of > > misdetection in encrypted data. I think we can rule that out > > for the moment. > > > That actually seems like a pretty big chance to me. esp. if a hard drive > manufacturer happens to have shipped a hard drive model where each hard > drive has this problem. fsck will not blindly trust a random superblock signature. All values inside the superblock are checked if they are plausible. It will scream loudly if superblock is screwed. The chance it will accept a random sector as valid superblock is very very close to zero. Richard --- Name and OpenPGP keys available from pgp key servers _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
