[FFmpeg-cvslog] avcodec/eacmv: Check input size for intra frames

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Sep 19 23:57:31 2024 +0200| [c3a1cbbf5d99337b5e99260eb95c84e65c7587f6] | committer: Michael Niedermayer

avcodec/eacmv: Check input size for intra frames

Fixes: Timeout
Fixes: 71135/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EACMV_fuzzer-6251879028293632

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c3a1cbbf5d99337b5e99260eb95c84e65c7587f6
---

 libavcodec/eacmv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/eacmv.c b/libavcodec/eacmv.c
index 43dba20fae..15d3550cb8 100644
--- a/libavcodec/eacmv.c
+++ b/libavcodec/eacmv.c
@@ -194,12 +194,15 @@ static int cmv_decode_frame(AVCodecContext *avctx, AVFrame *frame,
     if ((ret = av_image_check_size(s->width, s->height, 0, s->avctx)) < 0)
         return ret;
 
+    buf += EA_PREAMBLE_SIZE;
+    if (!(buf[0]&1) && buf_end - buf < s->width * s->height * (int64_t)(100 - s->avctx->discard_damaged_percentage) / 100)
+        return AVERROR_INVALIDDATA;
+
     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
         return ret;
 
     memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
 
-    buf += EA_PREAMBLE_SIZE;
     if ((buf[0]&1)) {  // subtype
         cmv_decode_inter(s, frame, buf+2, buf_end);
         frame->flags &= ~AV_FRAME_FLAG_KEY;