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authorAlexander Barkov <bar@mariadb.com>2020-06-19 16:04:45 +0400
committerAlexander Barkov <bar@mariadb.com>2020-06-19 16:04:45 +0400
commit26907e7ef18964dad7b6b1fc19c7d1e65e915020 (patch)
treed54253093ea7b160600c0311532b5bcd94766e7f /sql/sql_show.cc
parentbf74f7f9ff40f8a17e739e9ab6f5c906ccb9e892 (diff)
downloadmariadb-git-26907e7ef18964dad7b6b1fc19c7d1e65e915020.tar.gz
MDEV-22941 Assertion `idx < array.elements' failed in Dynamic_array<st_mysql_const_lex_string*>::at
The code in fill_schema_schemata() did not take into account that make_db_list() can leave empty db_names if the requested database name was too long, so the call for db_names.at(0) crashed on assert. - Moving the code testing if the database directory exists into a separate function verify_database_directory_exists() - Modifying the test to check if db_names is not empty
Diffstat (limited to 'sql/sql_show.cc')
-rw-r--r--sql/sql_show.cc40
1 files changed, 27 insertions, 13 deletions
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 4f217159e5c..70cab968f43 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -4953,6 +4953,29 @@ bool store_schema_shemata(THD* thd, TABLE *table, LEX_STRING *db_name,
}
+/*
+ Check if the specified database exists on disk.
+
+ @param dbname - the database name
+ @retval true - on error, the database directory does not exists
+ @retval false - on success, the database directory exists
+*/
+static bool verify_database_directory_exists(const LEX_STRING &dbname)
+{
+ DBUG_ENTER("verity_database_exists");
+ char path[FN_REFLEN + 16];
+ uint path_len;
+ MY_STAT stat_info;
+ if (!dbname.str[0])
+ DBUG_RETURN(true); // Empty database name: does not exits.
+ path_len= build_table_filename(path, sizeof(path) - 1, dbname.str, "", "", 0);
+ path[path_len - 1]= 0;
+ if (!mysql_file_stat(key_file_misc, path, &stat_info, MYF(0)))
+ DBUG_RETURN(true); // The database directory was not found: does not exists.
+ DBUG_RETURN(false); // The database directory was found.
+}
+
+
int fill_schema_schemata(THD *thd, TABLE_LIST *tables, COND *cond)
{
/*
@@ -4981,19 +5004,10 @@ int fill_schema_schemata(THD *thd, TABLE_LIST *tables, COND *cond)
If we have lookup db value we should check that the database exists
*/
if(lookup_field_vals.db_value.str && !lookup_field_vals.wild_db_value &&
- db_names.at(0) != &INFORMATION_SCHEMA_NAME)
- {
- char path[FN_REFLEN+16];
- uint path_len;
- MY_STAT stat_info;
- if (!lookup_field_vals.db_value.str[0])
- DBUG_RETURN(0);
- path_len= build_table_filename(path, sizeof(path) - 1,
- lookup_field_vals.db_value.str, "", "", 0);
- path[path_len-1]= 0;
- if (!mysql_file_stat(key_file_misc, path, &stat_info, MYF(0)))
- DBUG_RETURN(0);
- }
+ (!db_names.elements() /* The database name was too long */||
+ (db_names.at(0) != &INFORMATION_SCHEMA_NAME &&
+ verify_database_directory_exists(lookup_field_vals.db_value))))
+ DBUG_RETURN(0);
for (size_t i=0; i < db_names.elements(); i++)
{