@@ -399,9 +399,14 @@ ole2_read_block(ole2_header_t * hdr, void *buff, unsigned int size, int32_t bloc

         return FALSE;

     }

     /* other methods: (blockno+1) * 512 or (blockno * block_size) + 512; */

+    if ((uint64_t) blockno << hdr->log2_big_block_size < INT32_MAX) {

     offset = (blockno << hdr->log2_big_block_size) + MAX(512, 1 << hdr->log2_big_block_size);   /* 512 is header size */

-

     offend = offset + size;

+    } else {

+        offset = INT32_MAX - size;

+        offend = INT32_MAX;

+    }

+

     if ((offend <= 0) || (offset < 0) || (offset >= hdr->m_length)) {

         return FALSE;

     } else if (offend > hdr->m_length) {

@@ -268,7 +268,7 @@ char *cli_utf16toascii(const char *str, unsigned int length)

 	return NULL;

     for(i = 0, j = 0; i < length; i += 2, j++) {

-       decoded[j] = str[i + 1] << 4;

+        decoded[j] = ((unsigned char) str[i + 1]) << 4;

        decoded[j] += str[i];

     }