[FFmpeg-devel] [PATCH 1/4] avcodec/tiff: Check the linearization table size

Michael Niedermayer michael at niedermayer.cc
Thu Aug 20 11:50:43 EEST 2020


Fixes: out of array access
Fixes: 24604/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-4843529818603520

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/tiff.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 08dbca9d60..8c0b6f0853 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -1434,7 +1434,9 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
             s->sub_ifd = ff_tget(&s->gb, TIFF_LONG, s->le); /** Only get the first SubIFD */
         break;
     case DNG_LINEARIZATION_TABLE:
-        for (int i = 0; i < FFMIN(count, 1 << s->bpp); i++)
+        if (count > FF_ARRAY_ELEMS(s->dng_lut))
+            return AVERROR_INVALIDDATA;
+        for (int i = 0; i < count; i++)
             s->dng_lut[i] = ff_tget(&s->gb, type, s->le);
         break;
     case DNG_BLACK_LEVEL:
-- 
2.17.1



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