h264_cavlc: check the value of run_before
authorAnton Khirnov <anton@khirnov.net>
Wed, 28 Dec 2016 12:02:02 +0000 (13:02 +0100)
committerAnton Khirnov <anton@khirnov.net>
Sun, 12 Mar 2017 19:42:13 +0000 (20:42 +0100)
commit522d850e68ec4b77d3477b3c8f55b1ba00a9d69a
treec05e311e00ff1ab3866dd16229a636a7c7e2bd83
parent83b2b34d06e74cc8775ba3d833f9782505e17539
h264_cavlc: check the value of run_before

Section 9.2.3.2 of the spec implies that run_before must not be larger
than zeros_left.

Fixes invalid reads with corrupted files.

CC: libav-stable@libav.org
Bug-Id: 1000
Found-By: Kamil Frankowicz
libavcodec/h264_cavlc.c