Offset sanity checks

src/devil1geo.c

@@ -100,7 +100,8 @@ static bool getmeshbatch(struct Batch *b,
 // assume client has allocated memory for mesh
 static bool getmesh(struct Mesh *m,
              unsigned int i,
-             const char * const filedata) {        
+             const char * const filedata,
+             unsigned int filesize) {
     bool done = false;
     if (m == NULL || filedata == NULL || m -> b == NULL) {
         return done;
@@ -112,6 +113,9 @@ static bool getmesh(struct Mesh *m,
         struct Batch b;
         for (j = 0; j < mh -> numBatch; j++) {
             unsigned int offset = mh->offsetBatches + j * sizeof(struct BatchData);
+            if (offset > filesize) {
+              return done;
+            }
             getmeshbatch(&b, offset, filedata);
 //            printmeshbatch(&b);
             m -> b[j] = b;

src/devil1pld.c

@@ -8,7 +8,9 @@ static bool getpldh(struct PldHeader *ph, const char *filedata) {
     if (ph != NULL && filedata != NULL) {
         ph -> numOffset = (int32_t)filedata[0];
         ph -> offsets   = (uint32_t*)(filedata + sizeof(int32_t));
-        good = true;
+        if ( ph->numOffset > 0 ) {
+          good = true;
+        }
     }
     return good;
 }

src/devil1tex.c

@@ -37,7 +37,7 @@ static bool gettexdescriptor(struct TextureBatchDescriptor **descriptor,
     bool done = false;
     unsigned int offset = sizeof(struct TexturePack);
     offset += sizeof(struct TextureBatchDescriptor) * i;
-    if (filedata != NULL) {
+    if (filedata != NULL && offset <= filesize) {
         *descriptor = (struct TextureBatchDescriptor*)(filedata + offset);
         done = true;
     }