From 1fe858136b315796dd5349f3b4448a29d1bd6fa1 Mon Sep 17 00:00:00 2001 From: Ganesh Ajjanagadde Date: Mon, 22 Feb 2016 23:21:58 -0500 Subject: [PATCH] utvideodec: Prevent possible signed overflow Doing slice_end - slice_start is unsafe and can lead to undefined behavior until slice_end has been properly sanitized. Reviewed-by: Ronald S. Bultje Signed-off-by: Ganesh Ajjanagadde Signed-off-by: Luca Barbato --- libavcodec/utvideodec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/utvideodec.c b/libavcodec/utvideodec.c index 808e3be067..2aaf861e62 100644 --- a/libavcodec/utvideodec.c +++ b/libavcodec/utvideodec.c @@ -361,12 +361,12 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, slice_end = 0; for (j = 0; j < c->slices; j++) { slice_end = bytestream2_get_le32u(&gb); - slice_size = slice_end - slice_start; - if (slice_end < 0 || slice_size < 0 || + if (slice_end < 0 || slice_end < slice_start || bytestream2_get_bytes_left(&gb) < slice_end) { av_log(avctx, AV_LOG_ERROR, "Incorrect slice size\n"); return AVERROR_INVALIDDATA; } + slice_size = slice_end - slice_start; slice_start = slice_end; max_slice_size = FFMAX(max_slice_size, slice_size); }