[FFmpeg-cvslog] avcodec/cri: check for available input in unpack_10bit()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Nov  9 23:31:30 2020 +0100| [43c8d3097b8254d08f5413a1934c001327859f47] | committer: Michael Niedermayer

avcodec/cri: check for available input in unpack_10bit()

Fixes: Timeout (>20sec -> 56ms)
Fixes: 26995/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CRI_fuzzer-5107217080254464

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=43c8d3097b8254d08f5413a1934c001327859f47
---

 libavcodec/cri.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/libavcodec/cri.c b/libavcodec/cri.c
index 5234f49965..41be29eabb 100644
--- a/libavcodec/cri.c
+++ b/libavcodec/cri.c
@@ -80,10 +80,13 @@ static void unpack_10bit(GetByteContext *gb, uint16_t *dst, int shift,
     int pos = 0;
 
     while (count > 0) {
-        uint32_t a0 = bytestream2_get_le32(gb);
-        uint32_t a1 = bytestream2_get_le32(gb);
-        uint32_t a2 = bytestream2_get_le32(gb);
-        uint32_t a3 = bytestream2_get_le32(gb);
+        uint32_t a0, a1,a2,a3;
+        if (bytestream2_get_bytes_left(gb) < 4)
+            break;
+        a0 = bytestream2_get_le32(gb);
+        a1 = bytestream2_get_le32(gb);
+        a2 = bytestream2_get_le32(gb);
+        a3 = bytestream2_get_le32(gb);
         dst[pos] = (((a0 >> 1) & 0xE00) | (a0 & 0x1FF)) << shift;
         pos++;
         if (pos >= w) {