avformat/mxfdec: Check first case of offset_temp computation for overflow

This is kind of ugly
Fixes: signed integer overflow: 255 * 1157565362826411919 cannot be represented in type 'long'
Fixes: 67313/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-6250434245230592

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 2024-03-29 03:35:18 +01:00
parent 7b7eea8e63
commit d6ed6f6e8d
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@ -1892,9 +1892,13 @@ static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_t
if (edit_unit < s->index_start_position + s->index_duration) { if (edit_unit < s->index_start_position + s->index_duration) {
int64_t index = edit_unit - s->index_start_position; int64_t index = edit_unit - s->index_start_position;
if (s->edit_unit_byte_count) if (s->edit_unit_byte_count) {
if (index > INT64_MAX / s->edit_unit_byte_count ||
s->edit_unit_byte_count * index > INT64_MAX - offset_temp)
return AVERROR_INVALIDDATA;
offset_temp += s->edit_unit_byte_count * index; offset_temp += s->edit_unit_byte_count * index;
else { } else {
if (s->nb_index_entries == 2 * s->index_duration + 1) if (s->nb_index_entries == 2 * s->index_duration + 1)
index *= 2; /* Avid index */ index *= 2; /* Avid index */