[FFmpeg-devel] [PATCH] avcodec/qpeg: Limit copy in qpeg_decode_intra() to the available bytes

Michael Niedermayer michael at niedermayer.cc
Sun Feb 24 01:44:40 EET 2019


Fixes: Timeout (27 sec -> 39 milli sec)
Fixes: 13151/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QPEG_fuzzer-5717536023248896

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/qpeg.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/qpeg.c b/libavcodec/qpeg.c
index 654fd998d6..d4195c5f0b 100644
--- a/libavcodec/qpeg.c
+++ b/libavcodec/qpeg.c
@@ -99,6 +99,8 @@ static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
                 }
             }
         } else {
+            if (bytestream2_get_bytes_left(&qctx->buffer) < copy)
+                copy = bytestream2_get_bytes_left(&qctx->buffer);
             for(i = 0; i < copy; i++) {
                 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
                 if (filled >= width) {
-- 
2.20.1



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