ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinha...@outlook.com> | Mon Feb 26 22:37:04 2024 +0100| [1bb7d5ca9fc6dc1b961014255ada03dee40bac31] | committer: Andreas Rheinhardt
avformat/mov: Don't use entry[-1] in pointer arithmetic It is undefined behaviour. Fixes many failed tests with UBSan and GCC 13 like "src/libavformat/mov.c:4229:44: runtime error: store to address 0x5572abe20f80 with insufficient space for an object of type 'struct MOVIndexRange'" (The line number does not refer to the line where &entry[-1] is assigned.) Reviewed-by: James Almer <jamr...@gmail.com> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1bb7d5ca9fc6dc1b961014255ada03dee40bac31 --- libavformat/mov.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index 71e8f7ae8f..97caaa7723 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -4022,7 +4022,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st) int num_discarded_begin = 0; int first_non_zero_audio_edit = -1; int packet_skip_samples = 0; - MOVIndexRange *current_index_range; + MOVIndexRange *current_index_range = NULL; int found_keyframe_after_edit = 0; int found_non_empty_edit = 0; @@ -4038,7 +4038,6 @@ static void mov_fix_index(MOVContext *mov, AVStream *st) return; } msc->current_index_range = msc->index_ranges; - current_index_range = msc->index_ranges - 1; // Clean AVStream from traces of old index sti->index_entries = NULL; @@ -4225,8 +4224,9 @@ static void mov_fix_index(MOVContext *mov, AVStream *st) } // Update the index ranges array - if (current_index_range < msc->index_ranges || index != current_index_range->end) { - current_index_range++; + if (!current_index_range || index != current_index_range->end) { + current_index_range = current_index_range ? current_index_range + 1 + : msc->index_ranges; current_index_range->start = index; } current_index_range->end = index + 1; @@ -4289,7 +4289,8 @@ static void mov_fix_index(MOVContext *mov, AVStream *st) av_freep(&frame_duration_buffer); // Null terminate the index ranges array - current_index_range++; + current_index_range = current_index_range ? current_index_range + 1 + : msc->index_ranges; current_index_range->start = 0; current_index_range->end = 0; msc->current_index = msc->index_ranges[0].start; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
