[FFmpeg-devel] [PATCH v1] lavc/vvc: Validate num_signalled_palette_entries

[Frank Plowman]

"The value of CurrentPaletteSize[ startComp ] shall be in the range of 0
to maxNumPaletteEntries, inclusive."

Signed-off-by: Frank Plowman <post at frankplowman.com>
---
 libavcodec/vvc/ctu.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/libavcodec/vvc/ctu.c b/libavcodec/vvc/ctu.c
index 62c9d4f5c0..70800ba5fa 100644
--- a/libavcodec/vvc/ctu.c
+++ b/libavcodec/vvc/ctu.c
@@ -20,6 +20,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/error.h"
 #include "libavutil/refstruct.h"
 
 #include "cabac.h"
@@ -1873,7 +1874,7 @@ static void palette_predicted(VVCLocalContext *lc, const bool local_dual_tree, i
         cu->plt[c].size = nb_predicted;
 }
 
-static void palette_signaled(VVCLocalContext *lc, const bool local_dual_tree,
+static int palette_signaled(VVCLocalContext *lc, const bool local_dual_tree,
     const int start, const int end, const int max_entries)
 {
     const VVCSPS *sps         = lc->fc->ps.sps;
@@ -1883,6 +1884,9 @@ static void palette_signaled(VVCLocalContext *lc, const bool local_dual_tree,
     const int size            = nb_predicted + nb_signaled;
     const bool dual_tree_luma = local_dual_tree && cu->tree_type == DUAL_TREE_LUMA;
 
+    if (size > max_entries)
+        return AVERROR_INVALIDDATA;
+
     for (int c = start; c < end; c++) {
         Palette *plt = cu->plt + c;
         for (int i = nb_predicted; i < size; i++) {
@@ -1894,6 +1898,8 @@ static void palette_signaled(VVCLocalContext *lc, const bool local_dual_tree,
         }
         plt->size = size;
     }
+
+    return 0;
 }
 
 static void palette_update_predictor(VVCLocalContext *lc, const bool local_dual_tree, int start, int end,
@@ -2070,7 +2076,7 @@ static int hls_palette_coding(VVCLocalContext *lc, const VVCTreeType tree_type)
     int max_index                 = 0;
     int prev_run_pos              = 0;
 
-    int predictor_size, start, end;
+    int predictor_size, start, end, ret;
     bool reused[VVC_MAX_NUM_PALETTE_PREDICTOR_SIZE];
     uint8_t run_type[MAX_PALETTE_CU_SIZE * MAX_PALETTE_CU_SIZE];
     uint8_t index[MAX_PALETTE_CU_SIZE * MAX_PALETTE_CU_SIZE];
@@ -2083,7 +2089,9 @@ static int hls_palette_coding(VVCLocalContext *lc, const VVCTreeType tree_type)
     predictor_size = pp[start].size;
     memset(reused, 0, sizeof(reused[0]) * predictor_size);
     palette_predicted(lc, local_dual_tree, start, end, reused, predictor_size, max_entries);
-    palette_signaled(lc, local_dual_tree, start, end, max_entries);
+    ret = palette_signaled(lc, local_dual_tree, start, end, max_entries);
+    if (ret < 0)
+        return ret;
     palette_update_predictor(lc, local_dual_tree, start, end, reused, predictor_size);
 
     if (cu->plt[start].size > 0)
-- 
2.47.0