libtiff: integer overflow in _TIFFCheckMalloc and _TIFFCheckRealloc in tif_aux.c

TIFFCheckMalloc and TIFFCheckRealloc in tifaux.c in LibTIFF through 4.0.10 mishandle Integer Overflow checks because they rely on compiler behavior that is undefined by the applicable C standards. This can, for example, lead to an application crash...