openjpeg: Prevent an integer overflow in opj_jp2_apply_pclr.

third_party/libopenjpeg20/0022-jp2_apply_pclr_overflow.patch

+diff --git a/third_party/libopenjpeg20/jp2.c b/third_party/libopenjpeg20/jp2.c
+index a6648f6..350803a 100644
+--- a/third_party/libopenjpeg20/jp2.c
++++ b/third_party/libopenjpeg20/jp2.c
+@@ -990,7 +990,18 @@ static void opj_jp2_apply_pclr(opj_image_t *image, opj_jp2_color_t *color)
+       assert( i == pcol ); // probably wrong?
+       new_comps[i] = old_comps[cmp];
+     }
+-
++        /* Prevent integer overflow */
++        if (old_comps[cmp].h == 0 || old_comps[cmp].w > UINT_MAX / sizeof(OPJ_INT32) / old_comps[cmp].h) {
++            for (j = 0; j < i; ++j) {
++                if (new_comps[j].data) {
++                    opj_free(new_comps[j].data);
++                }
++            }
++            opj_free(new_comps);
++            new_comps = NULL;
++            return;
++        }
++        
+                /* Palette mapping: */
+                new_comps[i].data = (OPJ_INT32*)
+                                opj_malloc(old_comps[cmp].w * old_comps[cmp].h * sizeof(OPJ_INT32));
+@@ -1011,14 +1022,26 @@ 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 );
++        
++        /* Prevent null pointer access */
++        if (!old_comps[cmp].data || !new_comps[i].data) {
++            for (j = 0; j < nr_channels; ++j) {
++                if (new_comps[j].data) {
++                    opj_free(new_comps[j].data);
++                }
++            }
++            opj_free(new_comps);
++            new_comps = NULL;
++            return;
++        }
++        
+                max = new_comps[i].w * new_comps[i].h;
+ 
+                /* 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];
+       }
+@@ -1026,7 +1049,7 @@ static void opj_jp2_apply_pclr(opj_image_t *image, opj_jp2_color_t *color)
+     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;