[FFmpeg-cvslog] avformat/sbgdec: Check for negative duration

[Michael Niedermayer]

ffmpeg | branch: release/6.1 | Michael Niedermayer <michael at niedermayer.cc> | Tue Mar 26 00:39:49 2024 +0100| [d492fc3e5ea49078b847d1f9f7b55fc597bf6232] | committer: Michael Niedermayer

avformat/sbgdec: Check for negative duration

Fixes: signed integer overflow: 9223372036854775807 - -8000000 cannot be represented in type 'long'
Fixes: 62276/clusterfuzz-testcase-minimized-ffmpeg_dem_SBG_fuzzer-5133181743136768

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 0bed22d597b78999151e3bde0768b7fe763fc2a6)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d492fc3e5ea49078b847d1f9f7b55fc597bf6232
---

 libavformat/sbgdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/sbgdec.c b/libavformat/sbgdec.c
index b2662ea418..281fe6272e 100644
--- a/libavformat/sbgdec.c
+++ b/libavformat/sbgdec.c
@@ -386,7 +386,7 @@ static int parse_options(struct sbg_parser *p)
                 case 'L':
                     FORWARD_ERROR(parse_optarg(p, opt, &oarg));
                     r = str_to_time(oarg.s, &p->scs.opt_duration);
-                    if (oarg.e != oarg.s + r) {
+                    if (oarg.e != oarg.s + r || p->scs.opt_duration < 0) {
                         snprintf(p->err_msg, sizeof(p->err_msg),
                                  "syntax error for option -L");
                         return AVERROR_INVALIDDATA;