[FFmpeg-cvslog] avcodec/fits: Check gcount and pcount being non negative

[Michael Niedermayer]

ffmpeg | branch: release/4.3 | Michael Niedermayer <michael at niedermayer.cc> | Tue Feb  2 19:28:15 2021 +0100| [2d155dcb7eae50a448c71af9c2324eafd47a98f5] | committer: Michael Niedermayer

avcodec/fits: Check gcount and pcount being non negative

Fixes: signed integer overflow: 9223372036854775807 - -30069403896 cannot be represented in type 'long'
Fixes: 30046/clusterfuzz-testcase-minimized-ffmpeg_dem_FITS_fuzzer-5807144773484544

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 c000a9128815e7cee4316dc45605259bbaa138ff)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2d155dcb7eae50a448c71af9c2324eafd47a98f5
---

 libavcodec/fits.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/fits.c b/libavcodec/fits.c
index 25c33e06c8..97fa7abe80 100644
--- a/libavcodec/fits.c
+++ b/libavcodec/fits.c
@@ -205,8 +205,12 @@ int avpriv_fits_header_parse_line(void *avcl, FITSHeader *header, const uint8_t
         } else if (!strcmp(keyword, "GROUPS") && sscanf(value, "%c", &c) == 1) {
             header->groups = (c == 'T');
         } else if (!strcmp(keyword, "GCOUNT") && sscanf(value, "%"SCNd64"", &t) == 1) {
+            if (t < 0 || t > INT_MAX)
+                return AVERROR_INVALIDDATA;
             header->gcount = t;
         } else if (!strcmp(keyword, "PCOUNT") && sscanf(value, "%"SCNd64"", &t) == 1) {
+            if (t < 0 || t > INT_MAX)
+                return AVERROR_INVALIDDATA;
             header->pcount = t;
         }
         dict_set_if_not_null(metadata, keyword, value);