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[FFmpeg-devel,2/2] avformat/mov: Check size before subtraction

Message ID 20220117223245.31928-2-michael@niedermayer.cc
State Accepted
Commit d8d9d506a3de976b647bcbb8f76c7b8d30eff576
Headers show
Series [FFmpeg-devel,1/2] avcodec/cfhd: Avoid signed integer overflow in coeff | expand

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Commit Message

Michael Niedermayer Jan. 17, 2022, 10:32 p.m. UTC 
Fixes: signed integer overflow: -9223372036854775808 - 8 cannot be represented in type 'long'
Fixes: 43542/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-5237670148702208

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

diff --git a/libavformat/mov.c b/libavformat/mov.c
index e401cd39b5..063cc2bae2 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -7329,6 +7329,8 @@  static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         if (a.size == 0) {
             a.size = atom.size - total_size + 8;
         }
+        if (a.size < 0)
+            break;
         a.size -= 8;
         if (a.size < 0)
             break;