avformat/ipmovie: Check signature_buffer read

Fixes: use of uninitilaized data
Fixes: 385167047/clusterfuzz-testcase-minimized-ffmpeg_dem_IPMOVIE_fuzzer-5941477505564672

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2024-12-26 03:07:51 +01:00
parent 17b019c517
commit 788abe0d25
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@ -614,7 +614,8 @@ static int ipmovie_read_header(AVFormatContext *s)
ipmovie->avf = s;
avio_read(pb, signature_buffer, sizeof(signature_buffer));
if (avio_read(pb, signature_buffer, sizeof(signature_buffer)) != sizeof(signature_buffer))
return AVERROR_INVALIDDATA;
while (memcmp(signature_buffer, signature, sizeof(signature))) {
memmove(signature_buffer, signature_buffer + 1, sizeof(signature_buffer) - 1);
signature_buffer[sizeof(signature_buffer) - 1] = avio_r8(pb);