vp3: Check the framerate for validity

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
(cherry picked from commit 6fc8226e29055858f28973bb3d27b63b3b65e616)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
(cherry picked from commit b4c479a82adbb1301e3e549cd80cdd65208ddd05)

diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
index da70e66ab9acedea26baca034258a5741ad1d7c8..d8e16505a15c6a0feddf53cfff4a6176253e4b9e 100644 (file)
--- a/libavcodec/vp3.c
+++ b/libavcodec/vp3.c
@@ -2155,6 +2155,10 @@ static int theora_decode_header(AVCodecContext *avctx, GetBitContext *gb)
     fps.num = get_bits_long(gb, 32);
     fps.den = get_bits_long(gb, 32);
     if (fps.num && fps.den) {
+        if (fps.num < 0 || fps.den < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid framerate\n");
+            return AVERROR_INVALIDDATA;
+        }
         av_reduce(&avctx->time_base.num, &avctx->time_base.den,
                   fps.den, fps.num, 1<<30);
     }