firmware: google: check if size is valid when decoding VPD data

firmware: google: check if size is valid when decoding VPD data

The VPD implementation from Chromium Vital Product Data project used to
parse data from untrusted input without checking if the meta data is
invalid or corrupted. For example, the size from decoded content may
be negative value, or larger than whole input buffer. Such invalid data
may cause buffer overflow.

To fix that, the size parameters passed to vpd_decode functions should
be changed to unsigned integer (u32) type, and the parsing of entry
header should be refactored so every size field is correctly verified
before starting to decode.

Fixes: ad2ac9d5c5e0 ("firmware: Google VPD: import lib_vpd source files")
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190830022402.214442-1-hungte@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>