Add an invalid data type to avoid not initialized pointer to functions

Always initialize TDSCOLUMN->funcs to avoid NULL pointer dereferences. Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
FreeTDS · Apr 29, 2017 · 6522b32 · 6522b32
1 parent f0400f5
commit 6522b32
Show file tree

Hide file tree

Showing 4 changed files with 61 additions and 0 deletions.
diff --git a/include/freetds/data.h b/include/freetds/data.h
@@ -37,6 +37,14 @@
 	TDS_EXTRA_CHECK(tds_ ## name ## _check) \
 }
 
+tds_func_get_info tds_invalid_get_info;
+tds_func_row_len  tds_invalid_row_len;
+tds_func_get_data tds_invalid_get;
+tds_func_put_info_len tds_invalid_put_info_len;
+tds_func_put_info tds_invalid_put_info;
+tds_func_put_data tds_invalid_put;
+tds_func_check    tds_invalid_check;
+
 tds_func_get_info tds_generic_get_info;
 tds_func_row_len  tds_generic_row_len;
 tds_func_get_data tds_generic_get;
@@ -101,6 +109,7 @@ tds_func_check    tds_sybblob_check;
 #  define TDS_DEFINE_DEFAULT_FUNCS(name) \
 	const TDSCOLUMNFUNCS tds_ ## name ## _funcs = TDS_COMMON_FUNCS(name)
 
+TDS_DEFINE_DEFAULT_FUNCS(invalid);
 TDS_DEFINE_DEFAULT_FUNCS(generic);
 TDS_DEFINE_DEFAULT_FUNCS(numeric);
 TDS_DEFINE_DEFAULT_FUNCS(variant);

diff --git a/src/odbc/odbc_data.c b/src/odbc/odbc_data.c
@@ -421,6 +421,11 @@ data_sybblob_set_type_info(TDSCOLUMN * col, struct _drecord *drec, SQLINTEGER od
 	}
 }
 
+static void
+data_invalid_set_type_info(TDSCOLUMN * col, struct _drecord *drec, SQLINTEGER odbc_ver)
+{
+}
+
 void
 odbc_set_sql_type_info(TDSCOLUMN * col, struct _drecord *drec, SQLINTEGER odbc_ver)
 {
@@ -443,6 +448,7 @@ odbc_set_sql_type_info(TDSCOLUMN * col, struct _drecord *drec, SQLINTEGER odbc_v
 		TDS_COMMON_FUNCS(name), \
 		data_ ## name ## _set_type_info, \
 	}
+TDS_DEFINE_FUNCS(invalid);
 TDS_DEFINE_FUNCS(generic);
 TDS_DEFINE_FUNCS(numeric);
 TDS_DEFINE_FUNCS(variant);

diff --git a/src/tds/data.c b/src/tds/data.c
@@ -1674,6 +1674,42 @@ tds_sybblob_put(TDSSOCKET *tds, TDSCOLUMN *col, int bcp7)
 	return TDS_SUCCESS;
 }
 
+TDSRET
+tds_invalid_get_info(TDSSOCKET * tds, TDSCOLUMN * col)
+{
+	return TDS_FAIL;
+}
+
+TDS_INT
+tds_invalid_row_len(TDSCOLUMN *col)
+{
+	return 0;
+}
+
+TDSRET
+tds_invalid_get(TDSSOCKET * tds, TDSCOLUMN * col)
+{
+	return TDS_FAIL;
+}
+
+TDSRET
+tds_invalid_put_info(TDSSOCKET * tds, TDSCOLUMN * col)
+{
+	return TDS_FAIL;
+}
+
+unsigned
+tds_invalid_put_info_len(TDSSOCKET * tds, TDSCOLUMN * col)
+{
+	return 0;
+}
+
+TDSRET
+tds_invalid_put(TDSSOCKET *tds, TDSCOLUMN *col, int bcp7)
+{
+	return TDS_FAIL;
+}
+
 #if ENABLE_EXTRA_CHECKS
 int
 tds_generic_check(const TDSCOLUMN *col)
@@ -1752,6 +1788,12 @@ tds_sybblob_check(const TDSCOLUMN *col)
 {
 	return 1;
 }
+
+int
+tds_invalid_check(const TDSCOLUMN *col)
+{
+	return 1;
+}
 #endif
 
 
@@ -1766,6 +1808,7 @@ TDS_DECLARE_FUNCS(msdatetime);
 TDS_DECLARE_FUNCS(clrudt);
 TDS_DECLARE_FUNCS(sybbigtime);
 TDS_DECLARE_FUNCS(sybblob);
+TDS_DECLARE_FUNCS(invalid);
 #include <freetds/popvis.h>
 
 static const TDSCOLUMNFUNCS *

diff --git a/src/tds/mem.c b/src/tds/mem.c
@@ -118,6 +118,8 @@ tds_get_dynid(TDSCONNECTION * conn, char *id)
 	return id;
 }
 
+extern const TDSCOLUMNFUNCS tds_invalid_funcs;
+
 static TDSCOLUMN *
 tds_alloc_column(void)
 {
@@ -127,6 +129,7 @@ tds_alloc_column(void)
 	tds_dstr_init(&col->table_name);
 	tds_dstr_init(&col->column_name);
 	tds_dstr_init(&col->table_column_name);
+	col->funcs = &tds_invalid_funcs;
 
       Cleanup:
 	return col;