From ed412d285078c167a3a5326bcb16b2169b488943 Mon Sep 17 00:00:00 2001 From: Andreas Cadhalpun Date: Tue, 13 Dec 2016 00:43:21 +0100 Subject: [PATCH] tiff: fix overflows when calling av_reduce The arguments of av_reduce are signed, so the cast to uint64_t is misleading. Reviewed-by: Michael Niedermayer Signed-off-by: Andreas Cadhalpun --- libavcodec/tiff.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c index 4721e94449..7ccda51404 100644 --- a/libavcodec/tiff.c +++ b/libavcodec/tiff.c @@ -772,9 +772,18 @@ static void set_sar(TiffContext *s, unsigned tag, unsigned num, unsigned den) int offset = tag == TIFF_YRES ? 2 : 0; s->res[offset++] = num; s->res[offset] = den; - if (s->res[0] && s->res[1] && s->res[2] && s->res[3]) + if (s->res[0] && s->res[1] && s->res[2] && s->res[3]) { + uint64_t num = s->res[2] * (uint64_t)s->res[1]; + uint64_t den = s->res[0] * (uint64_t)s->res[3]; + if (num > INT64_MAX || den > INT64_MAX) { + num = num >> 1; + den = den >> 1; + } av_reduce(&s->avctx->sample_aspect_ratio.num, &s->avctx->sample_aspect_ratio.den, - s->res[2] * (uint64_t)s->res[1], s->res[0] * (uint64_t)s->res[3], INT32_MAX); + num, den, INT32_MAX); + if (!s->avctx->sample_aspect_ratio.den) + s->avctx->sample_aspect_ratio = (AVRational) {0, 1}; + } } static int tiff_decode_tag(TiffContext *s, AVFrame *frame)