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[FFmpeg-devel,2/2] avcodec/mjpegdec: Fix integer overflow in DC dequantization

Message ID 20180124033450.4520-2-michael@niedermayer.cc
State Accepted
Commit 1bfc1aa004950c5ad527d823a08b8a19eef34eb0
Headers show

Commit Message

Michael Niedermayer Jan. 24, 2018, 3:34 a.m. UTC 
Fixes: runtime error: signed integer overflow: -65535 * 65312 cannot be represented in type 'int'
Fixes: 4900/clusterfuzz-testcase-minimized-5769019744321536

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

Comments

Michael Niedermayer Jan. 27, 2018, 2:51 a.m. UTC | #1 
On Wed, Jan 24, 2018 at 04:34:50AM +0100, Michael Niedermayer wrote:
> Fixes: runtime error: signed integer overflow: -65535 * 65312 cannot be represented in type 'int'
> Fixes: 4900/clusterfuzz-testcase-minimized-5769019744321536
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/mjpegdec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

applied

[...]
diff mbox

Patch

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index e005dd0cd3..5055ee2826 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -715,7 +715,7 @@  static int decode_block(MJpegDecodeContext *s, int16_t *block, int component,
         av_log(s->avctx, AV_LOG_ERROR, "error dc\n");
         return AVERROR_INVALIDDATA;
     }
-    val = val * quant_matrix[0] + s->last_dc[component];
+    val = val * (unsigned)quant_matrix[0] + s->last_dc[component];
     val = av_clip_int16(val);
     s->last_dc[component] = val;
     block[0] = val;