On Mon, Nov 05, 2012 at 06:43:46PM +0000, Matthew Garrett wrote: > On Mon, Nov 05, 2012 at 10:37:52AM -0800, Josh Triplett wrote: > > On Mon, Nov 05, 2012 at 03:26:41PM +0000, Jan Beulich wrote: > > > Header length should be validated for all ACPI tables before accessing > > > any non-header field. > > > > > > The valid flags should also be check, as with it clear there's no point > > > in trying to go through the rest of the code (and there's no guarantee > > > that the other table contents are valid/consistent in that case). > > > > > > Signed-off-by: Jan Beulich <[email protected]> > > > > The length check seems reasonable. However, Matthew Garrett (already > > CCed) previously suggested to me that this code should not check the > > "valid" bit, and should instead present the information to userspace if > > otherwise valid (such as having image_address != 0). Matthew? > > Yeah, my interpretation of the spec is that "valid" indicates whether or > not the contents represent what's currently on the screen, not whether > or not the contents can be interpreted for other reasons.
Given that, in the absence of a real BIOS that interprets the spec differently than that, it sounds like we should drop the check for the valid bit. Jan, have you seen a real BIOS which disagrees with the above interpretation? If not, can you resubmit the patch with just the length check? - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
