| Message ID | AS8P250MB0744EFFDD33DAD5A9A8DDBC78F5A2@AS8P250MB0744.EURP250.PROD.OUTLOOK.COM |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,v2,1/2] Revert "avformat/mov: zero initialize the index ranges buffer" | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On 2/26/2024 7:15 PM, Andreas Rheinhardt wrote: > 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.) > > Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> > --- > Now switching to next_index_range in order to avoid > having to duplicate the current_index_range == NULL check. I prefer the first version. mov_fix_index() is called once per track during init (and then it may not be called depending on user options), so it's hardly a bottleneck, and next_index_range[-1] is much less clear and intuitive at a quick glance than current_index_range. > > libavformat/mov.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/libavformat/mov.c b/libavformat/mov.c > index 71e8f7ae8f..d7da19998b 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 *next_index_range; > int found_keyframe_after_edit = 0; > int found_non_empty_edit = 0; > > @@ -4038,7 +4038,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st) > return; > } > msc->current_index_range = msc->index_ranges; > - current_index_range = msc->index_ranges - 1; > + next_index_range = msc->index_ranges; > > // Clean AVStream from traces of old index > sti->index_entries = NULL; > @@ -4225,11 +4225,11 @@ 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++; > - current_index_range->start = index; > + if (next_index_range == msc->index_ranges || index != next_index_range[-1].end) { > + next_index_range->start = index; > + next_index_range++; > } > - current_index_range->end = index + 1; > + next_index_range[-1].end = index + 1; > > // Only start incrementing DTS in frame_duration amounts, when we encounter a frame in edit list. > if (edit_list_start_encountered > 0) { > @@ -4289,9 +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->start = 0; > - current_index_range->end = 0; > + next_index_range->start = 0; > + next_index_range->end = 0; > msc->current_index = msc->index_ranges[0].start; > } >
diff --git a/libavformat/mov.c b/libavformat/mov.c index 71e8f7ae8f..d7da19998b 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 *next_index_range; int found_keyframe_after_edit = 0; int found_non_empty_edit = 0; @@ -4038,7 +4038,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st) return; } msc->current_index_range = msc->index_ranges; - current_index_range = msc->index_ranges - 1; + next_index_range = msc->index_ranges; // Clean AVStream from traces of old index sti->index_entries = NULL; @@ -4225,11 +4225,11 @@ 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++; - current_index_range->start = index; + if (next_index_range == msc->index_ranges || index != next_index_range[-1].end) { + next_index_range->start = index; + next_index_range++; } - current_index_range->end = index + 1; + next_index_range[-1].end = index + 1; // Only start incrementing DTS in frame_duration amounts, when we encounter a frame in edit list. if (edit_list_start_encountered > 0) { @@ -4289,9 +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->start = 0; - current_index_range->end = 0; + next_index_range->start = 0; + next_index_range->end = 0; msc->current_index = msc->index_ranges[0].start; }
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.) Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> --- Now switching to next_index_range in order to avoid having to duplicate the current_index_range == NULL check. libavformat/mov.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)