From 4ace000985eb0e3e403af2aeab008b2414b14a2b Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 15 Dec 2023 22:37:49 +0100 Subject: [PATCH] avformat/mov: do not set sign bit for chunk_offsets Fixes: signed integer overflow: 2314885530818453536 - -7412889664301817824 cannot be represented in type 'long' Fixes: 64296/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6304027146846208 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit cfc0a68d4d3192779e356a852e71b8218e7a00ab) Signed-off-by: Michael Niedermayer --- libavformat/mov.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index 206138707d..b8828041d7 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -2028,8 +2028,13 @@ static int mov_read_stco(MOVContext *c, AVIOContext *pb, MOVAtom atom) for (i = 0; i < entries && !pb->eof_reached; i++) sc->chunk_offsets[i] = avio_rb32(pb); else if (atom.type == MKTAG('c','o','6','4')) - for (i = 0; i < entries && !pb->eof_reached; i++) + for (i = 0; i < entries && !pb->eof_reached; i++) { sc->chunk_offsets[i] = avio_rb64(pb); + if (sc->chunk_offsets[i] < 0) { + av_log(c->fc, AV_LOG_WARNING, "Impossible chunk_offset\n"); + sc->chunk_offsets[i] = 0; + } + } else return AVERROR_INVALIDDATA;