[FFmpeg-devel] [PATCH] avformat/rpl: The associative law doesnt hold in C

Michael Niedermayer michael at niedermayer.cc
Fri Jun 11 00:45:08 EEST 2021


Add () to avoid undefined behavior
Fixes: signed integer overflow: 9223372036854775790 + 57 cannot be represented in type 'long'
Fixes: 34983/clusterfuzz-testcase-minimized-ffmpeg_dem_RPL_fuzzer-5765822923538432

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/rpl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/rpl.c b/libavformat/rpl.c
index fac377b68e..296cb2c984 100644
--- a/libavformat/rpl.c
+++ b/libavformat/rpl.c
@@ -103,7 +103,7 @@ static AVRational read_fps(const char* line, int* error)
         // Truncate any numerator too large to fit into an int64_t
         if (num > (INT64_MAX - 9) / 10 || den > INT64_MAX / 10)
             break;
-        num  = 10 * num + *line - '0';
+        num  = 10 * num + (*line - '0');
         den *= 10;
     }
     if (!num)
-- 
2.17.1



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