Re: [PATCH] Fix EDD3.0 data verification.

["H. Peter Anvin" <hpa@zytor.com>]

On 02/02/2011 03:21 AM, Gleb Natapov wrote:
> Check for nonzero path in edd_has_edd30() has no sense. First, it looks
> at the wrong memory. Device path starts at offset 30 of the info->params
> structure which is at offset 8 from the beginning of info structure, but
> code looks at info + 4 instead. This was correct when code was introduced,
> but around v2.6.4 three more fields were added to edd_info structure
> (commit 66b61a5c in history.git). Second, even if it will check correct
> memory it will always succeed since at offset 30 (params->key) there will
> be non-zero values otherwise previous check would fail.
> 
> The patch replaces this bogus check with one that verifies checksum.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>

This is incorrect; the right thing to do is to use the length byte to
verify the range that should be checksummed.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.