[FFmpeg-cvslog] avcodec/tiff: Avoid 0.0/0.0 in camera_xyz_coeff()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Nov 17 23:18:01 2022 +0100| [ff2d1bbe737539b9f564e53f84b7309bc2a38243] | committer: Michael Niedermayer

avcodec/tiff: Avoid 0.0/0.0 in camera_xyz_coeff()

Fixes: division by zero
Fixes: 52230/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-5922608915021824

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=ff2d1bbe737539b9f564e53f84b7309bc2a38243
---

 libavcodec/tiff.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 5b56892071..cde318d5e5 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -1896,6 +1896,8 @@ static void camera_xyz_coeff(TiffContext *s,
     for (i = 0; i < 3; i++) {
         for (num = j = 0; j < 3; j++)
             num += cam2rgb[i][j];
+        if (!num)
+            num = 1;
         for (j = 0; j < 3; j++)
             cam2rgb[i][j] /= num;
         s->premultiply[i] = 1.f / num;