From 69673d02790f7917d11055236ecfa20c9ff8771a Mon Sep 17 00:00:00 2001 From: Andreas Cadhalpun Date: Thu, 10 Nov 2016 22:09:03 +0100 Subject: [PATCH] smvjpegdec: make sure cur_frame is not negative This fixes a heap-buffer-overflow detected by AddressSanitizer. Reviewed-by: Michael Niedermayer Signed-off-by: Andreas Cadhalpun (cherry picked from commit 360bc0d90aa66cf21e9f488e77d21db18e01ec9c) Signed-off-by: Andreas Cadhalpun --- libavcodec/smvjpegdec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/smvjpegdec.c b/libavcodec/smvjpegdec.c index 9057e86161..e319e5781b 100644 --- a/libavcodec/smvjpegdec.c +++ b/libavcodec/smvjpegdec.c @@ -152,6 +152,10 @@ static int smvjpeg_decode_frame(AVCodecContext *avctx, void *data, int *data_siz cur_frame = avpkt->pts % s->frames_per_jpeg; + /* cur_frame is later used to calculate the buffer offset, so it mustn't be negative */ + if (cur_frame < 0) + cur_frame += s->frames_per_jpeg; + /* Are we at the start of a block? */ if (!cur_frame) { av_frame_unref(mjpeg_data);