ea: check chunk_size for validity.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 273e6af47b38391f2bcc157cca0423fe7fcbf55c)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 6a86b705e1d4b72f0dddfbe23ad3eed9947001d5)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit e74bc64dd376c4691a610ba62a66ed30affc97ec)

Conflicts:

	libavformat/electronicarts.c
(cherry picked from commit 38c45adfca299e3d96c07a700032695ec7ff2aeb)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
1 file changed