avformat/utils: Fix undefined behavior in ff_configure_buffers_for_index()

When e2_pts == INT64_MIN and e1_pts >= 0 the calculation of
e2_pts - e1_pts will overflow an int64_t.

Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Dale Curtis 2020-01-28 16:49:14 -08:00 committed by Michael Niedermayer
parent f3bb59209f
commit f15007afa9

View File

@ -2108,6 +2108,8 @@ void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance)
//We could use URLProtocol flags here but as many user applications do not use URLProtocols this would be unreliable
const char *proto = avio_find_protocol_name(s->url);
av_assert0(time_tolerance >= 0);
if (!proto) {
av_log(s, AV_LOG_INFO,
"Protocol name not provided, cannot determine if input is local or "
@ -2135,7 +2137,7 @@ void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance)
for (; i2 < st2->nb_index_entries; i2++) {
AVIndexEntry *e2 = &st2->index_entries[i2];
int64_t e2_pts = av_rescale_q(e2->timestamp, st2->time_base, AV_TIME_BASE_Q);
if (e2_pts - e1_pts < time_tolerance)
if (e2_pts < e1_pts || e2_pts - (uint64_t)e1_pts < time_tolerance)
continue;
pos_delta = FFMAX(pos_delta, e1->pos - e2->pos);
break;