In d5dbcc00d889fb17948b025a468b00ddbea9e058, it was hoped that detection
of subpicture overlaps could be performed at the tile level, so as to
avoid introducing per-CTU checks. Unfortunately since that patch,
fuzzing has indicated there are some structures involving
pps_subpic_one_or_more_tiles_slice where tile-level checking is not
sufficient. Performing the check at the CTU level should (touch wood)
be the be-all and and-all of this, as CTUs are the lowest common
denominator of the picture partitioning.
Signed-off-by: Frank Plowman <p...@frankplowman.com>
---
Changes since v1:
* Merge pps_add_ctus and pps_add_ctus_check
* Change if/else for early-exit where possible
---
libavcodec/vvc/ps.c | 71 ++++++++++++++++++++-------------------------
1 file changed, 31 insertions(+), 40 deletions(-)
diff --git a/libavcodec/vvc/ps.c b/libavcodec/vvc/ps.c
index e8c312d8ac..ed96268bae 100644
--- a/libavcodec/vvc/ps.c
+++ b/libavcodec/vvc/ps.c
@@ -408,6 +408,8 @@ static int pps_add_ctus(VVCPPS *pps, int *off, const int
rx, const int ry,
int start = *off;
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
+ if (*off >= pps->ctb_count)
+ return AVERROR_INVALIDDATA;
pps->ctb_addr_in_slice[*off] = ctu_rs(rx + x, ry + y, pps);
(*off)++;
}
@@ -420,9 +422,11 @@ static void pps_single_slice_picture(VVCPPS *pps, int *off)
pps->num_ctus_in_slice[0] = 0;
for (int j = 0; j < pps->r->num_tile_rows; j++) {
for (int i = 0; i < pps->r->num_tile_columns; i++) {
- pps->num_ctus_in_slice[0] += pps_add_ctus(pps, off,
+ const int ret = pps_add_ctus(pps, off,
pps->col_bd[i], pps->row_bd[j],
pps->r->col_width_val[i], pps->r->row_height_val[j]);
+ av_assert2(ret >= 0);
+ pps->num_ctus_in_slice[0] += ret;
}
}
}
@@ -451,50 +455,36 @@ static void subpic_tiles(int *tile_x, int *tile_y, int
*tile_x_end, int *tile_y_
(*tile_y_end)++;
}
-static bool mark_tile_as_used(bool *tile_in_subpic, const int tx, const int
ty, const int tile_columns)
-{
- const size_t tile_idx = ty * tile_columns + tx;
- if (tile_in_subpic[tile_idx]) {
- /* the tile is covered by other subpictures */
- return false;
- }
- tile_in_subpic[tile_idx] = true;
- return true;
-}
-
-static int pps_subpic_less_than_one_tile_slice(VVCPPS *pps, const VVCSPS *sps,
const int i, const int tx, const int ty, int *off, bool *tile_in_subpic)
+static int pps_subpic_less_than_one_tile_slice(VVCPPS *pps, const VVCSPS *sps,
const int i, const int tx, const int ty, int *off)
{
- const int subpic_bottom = sps->r->sps_subpic_ctu_top_left_y[i] +
sps->r->sps_subpic_height_minus1[i];
- const int tile_bottom = pps->row_bd[ty] + pps->r->row_height_val[ty] - 1;
- const bool is_final_subpic_in_tile = subpic_bottom == tile_bottom;
-
- if (is_final_subpic_in_tile && !mark_tile_as_used(tile_in_subpic, tx, ty,
pps->r->num_tile_columns))
- return AVERROR_INVALIDDATA;
-
- pps->num_ctus_in_slice[i] = pps_add_ctus(pps, off,
+ const int ret = pps_add_ctus(pps, off,
sps->r->sps_subpic_ctu_top_left_x[i],
sps->r->sps_subpic_ctu_top_left_y[i],
sps->r->sps_subpic_width_minus1[i] + 1,
sps->r->sps_subpic_height_minus1[i] + 1);
+ if (ret < 0)
+ return ret;
+ pps->num_ctus_in_slice[i] = ret;
return 0;
}
static int pps_subpic_one_or_more_tiles_slice(VVCPPS *pps, const int tile_x,
const int tile_y, const int x_end, const int y_end,
- const int i, int *off, bool *tile_in_subpic)
+ const int i, int *off)
{
for (int ty = tile_y; ty < y_end; ty++) {
for (int tx = tile_x; tx < x_end; tx++) {
- if (!mark_tile_as_used(tile_in_subpic, tx, ty,
pps->r->num_tile_columns))
- return AVERROR_INVALIDDATA;
-
- pps->num_ctus_in_slice[i] += pps_add_ctus(pps, off,
+ const int ret = pps_add_ctus(pps, off,
pps->col_bd[tx], pps->row_bd[ty],
pps->r->col_width_val[tx], pps->r->row_height_val[ty]);
+ if (ret < 0)
+ return ret;
+
+ pps->num_ctus_in_slice[i] += ret;
}
}
return 0;
}
-static int pps_subpic_slice(VVCPPS *pps, const VVCSPS *sps, const int i, int
*off, bool *tile_in_subpic)
+static int pps_subpic_slice(VVCPPS *pps, const VVCSPS *sps, const int i, int
*off)
{
int tx, ty, x_end, y_end;
@@ -503,9 +493,9 @@ static int pps_subpic_slice(VVCPPS *pps, const VVCSPS *sps,
const int i, int *of
subpic_tiles(&tx, &ty, &x_end, &y_end, sps, pps, i);
if (ty + 1 == y_end && sps->r->sps_subpic_height_minus1[i] + 1 <
pps->r->row_height_val[ty])
- return pps_subpic_less_than_one_tile_slice(pps, sps, i, tx, ty, off,
tile_in_subpic);
+ return pps_subpic_less_than_one_tile_slice(pps, sps, i, tx, ty, off);
else
- return pps_subpic_one_or_more_tiles_slice(pps, tx, ty, x_end, y_end,
i, off, tile_in_subpic);
+ return pps_subpic_one_or_more_tiles_slice(pps, tx, ty, x_end, y_end,
i, off);
}
static int pps_single_slice_per_subpic(VVCPPS *pps, const VVCSPS *sps, int
*off)
@@ -513,18 +503,11 @@ static int pps_single_slice_per_subpic(VVCPPS *pps, const
VVCSPS *sps, int *off)
if (!sps->r->sps_subpic_info_present_flag) {
pps_single_slice_picture(pps, off);
} else {
- bool tile_in_subpic[VVC_MAX_TILES_PER_AU] = {0};
for (int i = 0; i < pps->r->pps_num_slices_in_pic_minus1 + 1; i++) {
- const int ret = pps_subpic_slice(pps, sps, i, off, tile_in_subpic);
+ const int ret = pps_subpic_slice(pps, sps, i, off);
if (ret < 0)
return ret;
}
-
- // We only use tile_in_subpic to check that the subpictures don't
overlap
- // here; we don't use tile_in_subpic to check that the subpictures
cover
- // every tile. It is possible to avoid doing this work here because
the
- // covering property of subpictures is already guaranteed by the
mechanisms
- // which check every CTU belongs to a slice.
}
return 0;
}
@@ -538,9 +521,12 @@ static int pps_one_tile_slices(VVCPPS *pps, const int
tile_idx, int i, int *off)
ctu_xy(&rx, &ry, tile_x, tile_y, pps);
ctu_y_end = ry + r->row_height_val[tile_y];
while (ry < ctu_y_end) {
+ int ret;
pps->slice_start_offset[i] = *off;
- pps->num_ctus_in_slice[i] = pps_add_ctus(pps, off, rx, ry,
+ ret = pps_add_ctus(pps, off, rx, ry,
r->col_width_val[tile_x], r->slice_height_in_ctus[i]);
+ av_assert2(ret >= 0);
+ pps->num_ctus_in_slice[i] = ret;
ry += r->slice_height_in_ctus[i++];
}
i--;
@@ -557,13 +543,16 @@ static int pps_multi_tiles_slice(VVCPPS *pps, const int
tile_idx, const int i, i
pps->num_ctus_in_slice[i] = 0;
for (int ty = tile_y; ty <= tile_y +
r->pps_slice_height_in_tiles_minus1[i]; ty++) {
for (int tx = tile_x; tx <= tile_x +
r->pps_slice_width_in_tiles_minus1[i]; tx++) {
+ int ret;
const int idx = ty * r->num_tile_columns + tx;
if (tile_in_slice[idx])
return AVERROR_INVALIDDATA;
tile_in_slice[idx] = true;
ctu_xy(&rx, &ry, tx, ty, pps);
- pps->num_ctus_in_slice[i] += pps_add_ctus(pps, off, rx, ry,
+ ret = pps_add_ctus(pps, off, rx, ry,
r->col_width_val[tx], r->row_height_val[ty]);
+ av_assert2(ret >= 0);
+ pps->num_ctus_in_slice[i] += ret;
}
}
@@ -610,8 +599,10 @@ static void pps_no_rect_slice(VVCPPS* pps)
for (int tile_y = 0; tile_y < r->num_tile_rows; tile_y++) {
for (int tile_x = 0; tile_x < r->num_tile_columns; tile_x++) {
+ int ret;
ctu_xy(&rx, &ry, tile_x, tile_y, pps);
- pps_add_ctus(pps, &off, rx, ry, r->col_width_val[tile_x],
r->row_height_val[tile_y]);
+ ret = pps_add_ctus(pps, &off, rx, ry, r->col_width_val[tile_x],
r->row_height_val[tile_y]);
+ av_assert2(ret >= 0);
}
}
}
--
2.47.0
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