[FFmpeg-cvslog] avcodec/exr: Check for remaining bits in huf_unpack_enc_table()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Apr  1 02:15:07 2024 +0200| [589fa8a027f3b1707d78d7c45335acc498a5e887] | committer: Michael Niedermayer

avcodec/exr: Check for remaining bits in huf_unpack_enc_table()

Fixes: Timeout
Fixes: 67645/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EXR_fuzzer-6308760977997824

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=589fa8a027f3b1707d78d7c45335acc498a5e887
---

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

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 0f1f683e7e..09f2fca109 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -335,7 +335,10 @@ static int huf_unpack_enc_table(GetByteContext *gb,
         return ret;
 
     for (; im <= iM; im++) {
-        uint64_t l = freq[im] = get_bits(&gbit, 6);
+        uint64_t l;
+        if (get_bits_left(&gbit) < 6)
+            return AVERROR_INVALIDDATA;
+        l = freq[im] = get_bits(&gbit, 6);
 
         if (l == LONG_ZEROCODE_RUN) {
             int zerun = get_bits(&gbit, 8) + SHORTEST_LONG_RUN;