[FFmpeg-cvslog] avcodec/hevc_mp4toannexb: more validations for nalu_len

[Nuo Mi]

ffmpeg | branch: master | Nuo Mi <nuomi2021 at gmail.com> | Fri Feb  9 19:16:31 2024 +0800| [4f8044145532276715bbbc6598868ae4a234c6ce] | committer: Nuo Mi

avcodec/hevc_mp4toannexb: more validations for nalu_len

For a corrupted stream, the value of nalu_len read from the extradata is not reliable.
We need to perform additional checks

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4f8044145532276715bbbc6598868ae4a234c6ce
---

 libavcodec/bsf/hevc_mp4toannexb.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavcodec/bsf/hevc_mp4toannexb.c b/libavcodec/bsf/hevc_mp4toannexb.c
index d91229a895..8eec18f31e 100644
--- a/libavcodec/bsf/hevc_mp4toannexb.c
+++ b/libavcodec/bsf/hevc_mp4toannexb.c
@@ -65,9 +65,11 @@ static int hevc_extradata_to_annexb(AVBSFContext *ctx)
         }
 
         for (j = 0; j < cnt; j++) {
-            int nalu_len = bytestream2_get_be16(&gb);
+            const int nalu_len = bytestream2_get_be16(&gb);
 
-            if (4 + AV_INPUT_BUFFER_PADDING_SIZE + nalu_len > SIZE_MAX - new_extradata_size) {
+            if (!nalu_len ||
+                nalu_len > bytestream2_get_bytes_left(&gb) ||
+                4 + AV_INPUT_BUFFER_PADDING_SIZE + nalu_len > SIZE_MAX - new_extradata_size) {
                 ret = AVERROR_INVALIDDATA;
                 goto fail;
             }