[FFmpeg-devel] [PATCH 3/4] avformat/rmdec: Use 64bit for intermediate for DEINT_ID_INT4

Michael Niedermayer michael at niedermayer.cc
Thu Apr 15 23:44:19 EEST 2021


Fixes: runtime error: signed integer overflow: 65312 * 65535 cannot be represented in type 'int'
Fixes: 32832/clusterfuzz-testcase-minimized-ffmpeg_dem_RM_fuzzer-4817710040088576

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/rmdec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index fc3bff4859..af032ed90a 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -269,9 +269,9 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
         case DEINT_ID_INT4:
             if (ast->coded_framesize > ast->audio_framesize ||
                 sub_packet_h <= 1 ||
-                ast->coded_framesize * sub_packet_h > (2 + (sub_packet_h & 1)) * ast->audio_framesize)
+                ast->coded_framesize * (uint64_t)sub_packet_h > (2 + (sub_packet_h & 1)) * ast->audio_framesize)
                 return AVERROR_INVALIDDATA;
-            if (ast->coded_framesize * sub_packet_h != 2*ast->audio_framesize) {
+            if (ast->coded_framesize * (uint64_t)sub_packet_h != 2*ast->audio_framesize) {
                 avpriv_request_sample(s, "mismatching interleaver parameters");
                 return AVERROR_INVALIDDATA;
             }
-- 
2.17.1



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