Bug#11765108 (Bug#58036) client utf32, utf16, ucs2 should be disallowed, they crash server

Problem: ucs2 was correctly disallowed in "SET NAMES" only,
while mysql_real_connect() and mysql_change_user() still allowed
to use ucs2, which made server crash.

Fix: disallow ucs2 in mysql_real_connect() and mysql_change_user().

  @ sql/set_var.cc
    Using new function.

  @ sql/sql_acl.cc
    - Return error if character set initialization failed
    - Getting rid of pointer aliasing:
      Initialize user_name to NULL, to avoid double free().

  @ sql/sql_connect.cc
    - in case of unsupported client character set send error and return true
    - in case of success return false

  @ sql/sql_connect.h
    - changing return type for thd_init_client_charset() to bool,
      to return errors to the caller

  @ sql/sql_parse.h
    - introducing a new function, to reuse in all places where we need
    to check client character set.

  @ tests/mysql_client_test.c
    Adding test

1 files changed, 67 insertions, 0 deletions

diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 3861a3e1cf8..fa9e7c670ec 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -19289,6 +19289,72 @@ static void test_bug47485()
 
 
 /*
+  Bug#58036 client utf32, utf16, ucs2 should be disallowed, they crash server
+*/
+static void test_bug58036()
+{
+  MYSQL *conn;
+  DBUG_ENTER("test_bug47485");
+  myheader("test_bug58036");
+
+  /* Part1: try to connect with ucs2 client character set */
+  conn= mysql_client_init(NULL);
+  mysql_options(conn, MYSQL_SET_CHARSET_NAME, "ucs2");
+  if (mysql_real_connect(conn, opt_host, opt_user,
+                         opt_password,  opt_db ? opt_db : "test",
+                         opt_port, opt_unix_socket, 0))
+  {
+    if (!opt_silent)
+      printf("mysql_real_connect() succeeded (failure expected)\n");
+    mysql_close(conn);
+    DIE();
+  }
+
+  if (!opt_silent)
+    printf("Got mysql_real_connect() error (expected): %s (%d)\n",
+           mysql_error(conn), mysql_errno(conn));  
+  DIE_UNLESS(mysql_errno(conn) == ER_WRONG_VALUE_FOR_VAR);
+  mysql_close(conn);
+
+
+  /*
+    Part2:
+    - connect with latin1
+    - then change client character set to ucs2
+    - then try mysql_change_user()
+  */
+  conn= mysql_client_init(NULL);
+  mysql_options(conn, MYSQL_SET_CHARSET_NAME, "latin1");
+  if (!mysql_real_connect(conn, opt_host, opt_user,
+                         opt_password, opt_db ? opt_db : "test",
+                         opt_port, opt_unix_socket, 0))
+  {
+    if (!opt_silent)
+      printf("mysql_real_connect() failed: %s (%d)\n",
+             mysql_error(conn), mysql_errno(conn));
+    mysql_close(conn);
+    DIE();
+  }
+
+  mysql_options(conn, MYSQL_SET_CHARSET_NAME, "ucs2");
+  if (!mysql_change_user(conn, opt_user, opt_password, NULL))
+  {
+    if (!opt_silent)
+      printf("mysql_change_user() succedded, error expected!");
+    mysql_close(conn);
+    DIE();
+  }
+
+  if (!opt_silent)
+    printf("Got mysql_change_user() error (expected): %s (%d)\n",
+           mysql_error(conn), mysql_errno(conn));
+  mysql_close(conn);
+
+  DBUG_VOID_RETURN;
+}
+
+
+/*
   Bug#49972: Crash in prepared statements.
 
   The following case lead to a server crash:
@@ -19770,6 +19836,7 @@ static struct my_tests_st my_tests[]= {
   { "test_bug42373", test_bug42373 },
   { "test_bug54041", test_bug54041 },
   { "test_bug47485", test_bug47485 },
+  { "test_bug58036", test_bug58036 },
   { "test_bug57058", test_bug57058 },
   { 0, 0 }
 };