Check bits to decode will fit before decoding

When decoding the CPDF_HintTable we read the dwDeltaGroupLen value out
of the input stream which is a 16bit number. That value is then passed
in to read a uint32_t of the object number. If we have a group length of
> 32 bits we'll cause an undefined shift when we attempt to shift right
more then 32 bits.

This Cl bails out early if the dwDeltaGroupLen value is > 32 in order to
stop the undefined shifts.

Bug: chromium:718505
Change-Id: I919d6f4cd19826094a5e44d3a65d758029f5c236
Reviewed-on: https://pdfium-review.googlesource.com/5090
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

0 files changed, 0 insertions, 0 deletions