Bug#856448: gdk-pixbuf: CVE-2017-6314: Infinite loop in io-tiff.c with large size

[Salvatore Bonaccorso]

Control: severity -1 serious
Control: fixed -1 2.36.5-2+deb9u2

Raising severity to RC to avoid regression stretch->buster. It has
been fixed in a DSA for gdk-pixbuf for stretch.

Regards,
Salvatore