[FFmpeg-cvslog] avcodec/pixlet: fixes integer overflow in read_highpass()

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Thu Aug 17 03:54:56 2017 +0200| [53dae9585f1fefb80794112f348df9ea6bc134ec] | committer: Michael Niedermayer

avcodec/pixlet: fixes integer overflow in read_highpass()

Fixes: runtime error: negation of -2147483648 cannot be represented in type 'int32_t' (aka 'int'); cast to an unsigned type to negate this value to itself
Fixes: 2879/clusterfuzz-testcase-minimized-6317542639403008

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit cadab5a2a74d715fc16325bd89f8b8091def1083)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=53dae9585f1fefb80794112f348df9ea6bc134ec
---

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

diff --git a/libavcodec/pixlet.c b/libavcodec/pixlet.c
index a9661d3ab6..088226bdda 100644
--- a/libavcodec/pixlet.c
+++ b/libavcodec/pixlet.c
@@ -331,6 +331,9 @@ static int read_highpass(AVCodecContext *avctx, uint8_t *ptr, int plane, AVFrame
             return AVERROR_INVALIDDATA;
         }
 
+        if (a == INT32_MIN)
+            return AVERROR_INVALIDDATA;
+
         ret = read_high_coeffs(avctx, ptr + bytestream2_tell(&ctx->gb), dest, size,
                                c, (b >= FFABS(a)) ? b : a, d,
                                ctx->band[plane][i + 1].width, stride);