Fix bug #72293 - Heap overflow in mysqlnd related to BIT fields

diff --git a/ext/mysqlnd/mysqlnd_wireprotocol.c b/ext/mysqlnd/mysqlnd_wireprotocol.c
index 8f80bbaada1c20ab366d1194399864740940139a..5871c3c346e247165ff5b7a96eed1cee85b7bdf0 100644 (file)
--- a/ext/mysqlnd/mysqlnd_wireprotocol.c
+++ b/ext/mysqlnd/mysqlnd_wireprotocol.c
@@ -1608,6 +1608,7 @@ php_mysqlnd_rowp_read_text_protocol_aux(MYSQLND_MEMORY_POOL_CHUNK * row_buffer,
        zend_uchar * p = row_buffer->ptr;
        size_t data_size = row_buffer->app;
        zend_uchar * bit_area = (zend_uchar*) row_buffer->ptr + data_size + 1; /* we allocate from here */
+       const zend_uchar * const packet_end = (zend_uchar*) row_buffer->ptr + data_size;
 
        DBG_ENTER("php_mysqlnd_rowp_read_text_protocol_aux");
 
@@ -1619,11 +1620,15 @@ php_mysqlnd_rowp_read_text_protocol_aux(MYSQLND_MEMORY_POOL_CHUNK * row_buffer,
 
        for (i = 0, current_field = start_field; current_field < end_field; current_field++, i++) {
                /* php_mysqlnd_net_field_length() call should be after *this_field_len_pos = p; */
-               zend_ulong len = php_mysqlnd_net_field_length(&p);
+               const zend_ulong len = php_mysqlnd_net_field_length(&p);
 
                /* NULL or NOT NULL, this is the question! */
                if (len == MYSQLND_NULL_LENGTH) {
                        ZVAL_NULL(current_field);
+               } else if ((p + len) > packet_end) {
+                       php_error_docref(NULL, E_WARNING, "Malformed server packet. Field length pointing "MYSQLND_SZ_T_SPEC
+                                                                                         " bytes after end of packet", (p + len) - packet_end - 1);
+                       DBG_RETURN(FAIL);
                } else {
 #if defined(MYSQLND_STRING_TO_INT_CONVERSION)
                        struct st_mysqlnd_perm_bind perm_bind =