[FFmpeg-cvslog] avcodec/cbs_jpeg: Check length for SOS

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Mar  7 15:42:58 2020 +0100| [1812352d767ccf5431aa440123e2e260a4db2726] | committer: Michael Niedermayer

avcodec/cbs_jpeg: Check length for SOS

Fixes: out of array access
Fixes: 19734/clusterfuzz-testcase-minimized-ffmpeg_BSF_TRACE_HEADERS_fuzzer-5673507031875584
Fixes: 19353/clusterfuzz-testcase-minimized-ffmpeg_BSF_TRACE_HEADERS_fuzzer-5703944462663680

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=1812352d767ccf5431aa440123e2e260a4db2726
---

 libavcodec/cbs_jpeg.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/cbs_jpeg.c b/libavcodec/cbs_jpeg.c
index 6bbce5f89b..89512a26bb 100644
--- a/libavcodec/cbs_jpeg.c
+++ b/libavcodec/cbs_jpeg.c
@@ -197,6 +197,9 @@ static int cbs_jpeg_split_fragment(CodedBitstreamContext *ctx,
         if (marker == JPEG_MARKER_SOS) {
             length = AV_RB16(frag->data + start);
 
+            if (length > end - start)
+                return AVERROR_INVALIDDATA;
+
             data_ref = NULL;
             data     = av_malloc(end - start +
                                  AV_INPUT_BUFFER_PADDING_SIZE);