From 06f99cc4ddbb16f8fd9ae3d72835d542be3dbab2 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Sun, 6 Sep 2020 12:34:58 +0200 Subject: [PATCH] avformat/segment: Fix segfault on allocation error, avoid allocation If the user has set none of the options specifying the segments' durations, a default value of 2s is used by duplicating a "2" string and using av_parse_time() on it. Yet duplicating the string was unchecked and if the allocation failed, one would get a segfault in av_parse_time(). This commit solves this by turning said option into an option of type AV_OPT_TYPE_DURATION (which also uses av_parse_time() internally), avoiding duplicating the string altogether. Reviewed-by: Ridley Combs Signed-off-by: Andreas Rheinhardt --- libavformat/segment.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/libavformat/segment.c b/libavformat/segment.c index 0c96c8c50c..e84dc7a426 100644 --- a/libavformat/segment.c +++ b/libavformat/segment.c @@ -90,7 +90,6 @@ typedef struct SegmentContext { char *entry_prefix; ///< prefix to add to list entry filenames int list_type; ///< set the list type AVIOContext *list_pb; ///< list file put-byte context - char *time_str; ///< segment duration specification string int64_t time; ///< segment duration int use_strftime; ///< flag to expand filename with strftime int increment_tc; ///< flag to increment timecode if found @@ -689,7 +688,7 @@ static int seg_init(AVFormatContext *s) "you can use output_ts_offset instead of it\n"); } - if (!!seg->time_str + !!seg->times_str + !!seg->frames_str > 1) { + if ((seg->time != 2000000) + !!seg->times_str + !!seg->frames_str > 1) { av_log(s, AV_LOG_ERROR, "segment_time, segment_times, and segment_frames options " "are mutually exclusive, select just one of them\n"); @@ -703,15 +702,6 @@ static int seg_init(AVFormatContext *s) if ((ret = parse_frames(s, &seg->frames, &seg->nb_frames, seg->frames_str)) < 0) return ret; } else { - /* set default value if not specified */ - if (!seg->time_str) - seg->time_str = av_strdup("2"); - if ((ret = av_parse_time(&seg->time, seg->time_str, 1)) < 0) { - av_log(s, AV_LOG_ERROR, - "Invalid time duration specification '%s' for segment_time option\n", - seg->time_str); - return ret; - } if (seg->use_clocktime) { if (seg->time <= 0) { av_log(s, AV_LOG_ERROR, "Invalid negative segment_time with segment_atclocktime option set\n"); @@ -1051,7 +1041,7 @@ static const AVOption options[] = { { "segment_atclocktime", "set segment to be cut at clocktime", OFFSET(use_clocktime), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E}, { "segment_clocktime_offset", "set segment clocktime offset", OFFSET(clocktime_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, 86400000000LL, E}, { "segment_clocktime_wrap_duration", "set segment clocktime wrapping duration", OFFSET(clocktime_wrap_duration), AV_OPT_TYPE_DURATION, {.i64 = INT64_MAX}, 0, INT64_MAX, E}, - { "segment_time", "set segment duration", OFFSET(time_str),AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E }, + { "segment_time", "set segment duration", OFFSET(time),AV_OPT_TYPE_DURATION, {.i64 = 2000000}, INT64_MIN, INT64_MAX, E }, { "segment_time_delta","set approximation value used for the segment times", OFFSET(time_delta), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, E }, { "segment_times", "set segment split time points", OFFSET(times_str),AV_OPT_TYPE_STRING,{.str = NULL}, 0, 0, E }, { "segment_frames", "set segment split frame numbers", OFFSET(frames_str),AV_OPT_TYPE_STRING,{.str = NULL}, 0, 0, E },