[FFmpeg-cvslog] avcodec/fits: Check bscale

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Oct 18 21:54:14 2020 +0200| [c2ccd76fd000f69e355280b487213fb63821c8aa] | committer: Michael Niedermayer

avcodec/fits: Check bscale

Fixes: division by 0
Fixes: 26208/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FITS_fuzzer-6270472117026816

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=c2ccd76fd000f69e355280b487213fb63821c8aa
---

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

diff --git a/libavcodec/fits.c b/libavcodec/fits.c
index ad73ab70de..25c33e06c8 100644
--- a/libavcodec/fits.c
+++ b/libavcodec/fits.c
@@ -187,6 +187,8 @@ int avpriv_fits_header_parse_line(void *avcl, FITSHeader *header, const uint8_t
             header->blank = t;
             header->blank_found = 1;
         } else if (!strcmp(keyword, "BSCALE") && sscanf(value, "%lf", &d) == 1) {
+            if (d <= 0)
+                return AVERROR_INVALIDDATA;
             header->bscale = d;
         } else if (!strcmp(keyword, "BZERO") && sscanf(value, "%lf", &d) == 1) {
             header->bzero = d;