[coreboot-gerrit] Change in coreboot[master]: cbfstool: Support CONFIG_CBFS_VERIFICATION and metadata hash anchor

[Julius Werner (Code Review)]

Attention is currently required from: Furquan Shaikh, Angel Pons.
Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/41121 )

Change subject: cbfstool: Support CONFIG_CBFS_VERIFICATION and metadata hash anchor
......................................................................

Patch Set 21:

(1 comment)

File util/cbfstool/cbfs_glue.h:

https://review.coreboot.org/c/coreboot/+/41121/comment/368aaad0_13a4eb64 
PS21, Line 15: 	    buffer_size(&dev->buffer) - offset < size)
> AFAIUI, this check is to ensure `dev->buffer` is large enough to read `size` bytes at `offset`. […]

Yes, it's essentially the same thing, but it's written slightly more complicated to be overflow-safe. In your example, if (offset + size) was larger than the max value that can fit in size_t, the check might not catch it.

Granted, for cbfstool this is less likely to be an issue, but it doesn't hurt to be careful.