[FFmpeg-devel] [PATCH 3/6] avformat/nutdec: Check tmp_size

Michael Niedermayer michael at niedermayer.cc
Sun Apr 25 22:40:11 EEST 2021


Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_NUT_fuzzer-6739990530883584

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/nutdec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index d1f3496990..4dd26c50ff 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -286,6 +286,11 @@ static int decode_main_header(NUTContext *nut)
             ret = AVERROR_INVALIDDATA;
             goto fail;
         }
+        if (tmp_size < 0 || tmp_size > INT_MAX - count) {
+            av_log(s, AV_LOG_ERROR, "illegal size\n");
+            ret = AVERROR_INVALIDDATA;
+            goto fail;
+        }
 
         for (j = 0; j < count; j++, i++) {
             if (i == 'N') {
-- 
2.17.1



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