From 89c4c3c9442a86c747dbc09ef906e52a5c8635d5 Mon Sep 17 00:00:00 2001 From: Dale Curtis Date: Tue, 28 Jan 2020 16:49:14 -0800 Subject: [PATCH] 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 Signed-off-by: Michael Niedermayer (cherry picked from commit f15007afa90a3eb3639848d9702c1cc3ac3e896b) Signed-off-by: Michael Niedermayer --- libavformat/utils.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/libavformat/utils.c b/libavformat/utils.c index 8e61ae029d..47e712c252 100644 --- a/libavformat/utils.c +++ b/libavformat/utils.c @@ -2042,6 +2042,8 @@ 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->filename); + av_assert0(time_tolerance >= 0); + if (!proto) { av_log(s, AV_LOG_INFO, "Protocol name not provided, cannot determine if input is local or " @@ -2069,7 +2071,7 @@ 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;