openjpeg: Prevent an integer overflow in opj_jp2_apply_pclr.

third_party/libopenjpeg20/0022-jp2_apply_pclr_overflow.patch

Index: third_party/libopenjpeg20/0022-jp2_apply_pclr_overflow.patch
diff --git a/third_party/libopenjpeg20/0022-jp2_apply_pclr_overflow.patch b/third_party/libopenjpeg20/0022-jp2_apply_pclr_overflow.patch
new file mode 100644
index 0000000000000000000000000000000000000000..72105fec4ffdbb5e1e4e7849712f5d9ab8ebc963
--- /dev/null
+++ b/third_party/libopenjpeg20/0022-jp2_apply_pclr_overflow.patch
@@ -0,0 +1,53 @@
+diff --git a/third_party/libopenjpeg20/jp2.c b/third_party/libopenjpeg20/jp2.c
+index a6648f6..8128d98 100644
+--- a/third_party/libopenjpeg20/jp2.c
++++ b/third_party/libopenjpeg20/jp2.c
+@@ -972,6 +972,14 @@ static void opj_jp2_apply_pclr(opj_image_t *image, opj_jp2_color_t *color)
+ 	nr_channels = color->jp2_pclr->nr_channels;
+ 
+ 	old_comps = image->comps;
++	/* Overflow check: prevent integer overflow */
++	for (i = 0; i < nr_channels; ++i) {
++		cmp = cmap[i].cmp;
++		if (old_comps[cmp].h == 0 || old_comps[cmp].w > ((OPJ_UINT32)-1) / sizeof(OPJ_INT32) / old_comps[cmp].h) {
++			return;
++		}
++	}
++
+ 	new_comps = (opj_image_comp_t*)
+ 			opj_malloc(nr_channels * sizeof(opj_image_comp_t));
+ 	if (!new_comps) {
+@@ -1011,22 +1019,28 @@ static void opj_jp2_apply_pclr(opj_image_t *image, opj_jp2_color_t *color)
+ 		/* Palette mapping: */
+ 		cmp = cmap[i].cmp; pcol = cmap[i].pcol;
+ 		src = old_comps[cmp].data;
+-    assert( src );
++		dst = new_comps[i].data;
+ 		max = new_comps[i].w * new_comps[i].h;
+ 
++		/* Prevent null pointer access */
++		if (!src || !dst) {
++			for (j = 0; j < nr_channels; ++j) {
++				opj_free(new_comps[j].data);
++			}
++			opj_free(new_comps);
++			new_comps = NULL;
++			return;
++		}
++
+ 		/* Direct use: */
+     if(cmap[i].mtyp == 0) {
+       assert( cmp == 0 ); // probably wrong.
+-      dst = new_comps[i].data;
+-      assert( dst );
+       for(j = 0; j < max; ++j) {
+         dst[j] = src[j];
+       }
+     }
+     else {
+       assert( i == pcol ); // probably wrong?
+-      dst = new_comps[i].data;
+-      assert( dst );
+       for(j = 0; j < max; ++j) {
+         /* The index */
+         if((k = src[j]) < 0) k = 0; else if(k > top_k) k = top_k;