Bug#29201665: ASAN MEMORY LEAK IN LOG_EVENT::WRITE_HEADER() IN MYSQL-5.7

This fix is a backport of Bug#22732184.

The root cause is that executing 'FLUSH LOGS' tries to write a
Rotate_log_event into an uninitialized log_file. This happens if
there is no binlog file before executing 'FLUSH LOGS'.

To fix the problem, do not write a Rotate_log_event into an
uninitialized log_file in any case.

RB:22182

Author: vpvenugo

mysql-test/suite/binlog/r/binlog_check_flush_log_assertion.result

@@ -1,18 +1,16 @@
 SET GLOBAL binlog_error_action= IGNORE_ERROR;
-SET GLOBAL debug='+d,error_unique_log_filename';
+# Adding debug point 'error_unique_log_filename' to @@GLOBAL.debug
 FLUSH LOGS;
 ERROR HY000: Can't generate a unique log-filename master-bin.(1-999)
 
 # restart
 SET GLOBAL binlog_error_action= IGNORE_ERROR;
-SET GLOBAL debug='+d,error_unique_log_filename';
+# Adding debug point 'error_unique_log_filename' to @@GLOBAL.debug
 RESET MASTER;
 ERROR HY000: Can't generate a unique log-filename master-bin.(1-999)
 
-SET GLOBAL debug='-d,error_unique_log_filename';
-SET @@GLOBAL.DEBUG= @debug_save;
+# Removing debug point 'error_unique_log_filename' from @@GLOBAL.debug
 RESET MASTER;
 ERROR HY000: Target log not found in binlog index
 SET GLOBAL binlog_error_action= ABORT_SERVER;
 FLUSH LOGS;
-RESET MASTER;

mysql-test/suite/binlog/t/binlog_check_flush_log_assertion.test

@@ -1,72 +1,52 @@
 # ==== Purpose ====
 #
-# Bug #20592961  'FLUSH LOGS' POST FAULT INJECTION HITS ASSERT `! IS_SET()' AT SQL_ERROR.CC:381
+# Verify that 'FLUSH LOGS' does not cause assertion failure any more,
+# even if there is no binlog file before executing it.
 #
-# If we inject some fault in binary index file using debug options,
-# then 'flush logs' command will hit the assertion failure
-# '! is_set()' at sql_error.cc:381. The root cause is that the
-# 'flush logs' command missed to handle an 'Bad file descriptor'
-# error while flushing io cache.
+# ==== Implementation ====
 #
-# To fix the problem, handle the 'Bad file descriptor' error
-# while flushing io cache in the case.
-#
-# Steps to reproduce:
 # 1) SET GLOBAL debug='d,error_unique_log_filename' to
-#    cause 'FLUSH LOGS' error and 'RESET MASTER' error.
-# 2) Execute 'FLUSH LOGS' to cause crash.
-# 3) Restart and reset the server.
+#    cause 'FLUSH LOGS' and 'RESET MASTER' commands to error out.
+# 2) Execute 'FLUSH LOGS' to verify that it does not cause
+#    assertion failure any more.
+#
+# ==== References ====
 #
+# Bug#20592961: 'FLUSH LOGS' POST FAULT INJECTION HITS ASSERT `! IS_SET()' AT SQL_ERROR.CC:381
+# Bug#29201665: ASAN MEMORY LEAK IN LOG_EVENT::WRITE_HEADER() IN MYSQL-5.7
 
 # Test in this file is binlog format agnostic, thus no need
 # to rerun them for every format.
 --source include/have_binlog_format_row.inc
 --source include/have_debug.inc
-# Do not run the test with valgrind, since the
-# server may intentionally crash in the test.
---source include/not_valgrind.inc
 
 --disable_query_log
 call mtr.add_suppression("Can't generate a unique log-filename");
-call mtr.add_suppression("The server was unable to create a new log file. An incident event has been written to the binary log which will stop the slaves.");
 call mtr.add_suppression("MYSQL_BIN_LOG::open failed to generate new file name.");
 call mtr.add_suppression("Failed to locate old binlog or relay log files");
-call mtr.add_suppression('Attempting backtrace');
-call mtr.add_suppression("Either disk is full or file system is read only");
 call mtr.add_suppression('Could not open .*');
 --enable_query_log
 SET GLOBAL binlog_error_action= IGNORE_ERROR;
-SET GLOBAL debug='+d,error_unique_log_filename';
+--let $debug_point= error_unique_log_filename
+--source include/add_debug_point.inc
 
 --error ER_NO_UNIQUE_LOGFILE
 FLUSH LOGS;
 
 # Restart the server to enable binary log.
 --source include/restart_mysqld.inc
 SET GLOBAL binlog_error_action= IGNORE_ERROR;
-SET GLOBAL debug='+d,error_unique_log_filename';
+--source include/add_debug_point.inc
 
 --error ER_NO_UNIQUE_LOGFILE
 RESET MASTER;
 
-SET GLOBAL debug='-d,error_unique_log_filename';
-SET @@GLOBAL.DEBUG= @debug_save;
+--source include/remove_debug_point.inc
 
 --error ER_UNKNOWN_TARGET_BINLOG
 RESET MASTER;
 SET GLOBAL binlog_error_action= ABORT_SERVER;
 
---exec echo "wait" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
-
-# The following query may cause ER_BINLOG_LOGGING_IMPOSSIBLE error,
-# lost connection to MySQL server or succeed. And it does not cause
-# assertion failure any more.
---error 0,ER_BINLOG_LOGGING_IMPOSSIBLE,2013
+# Verify that 'FLUSH LOGS' does not cause assertion failure any more,
+# even if there is no binlog before executing it.
 FLUSH LOGS;
-
-# Restart and reset the server
---exec echo "restart" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
---enable_reconnect
---source include/wait_until_connected_again.inc
---disable_reconnect
-RESET MASTER;

sql/binlog.cc

@@ -7046,7 +7046,11 @@ int MYSQL_BIN_LOG::new_file_impl(bool need_lock_log, Format_description_log_even
     close_on_error= TRUE;
     goto end;
   }
-  else
+  /*
+    Make sure that the log_file is initialized before writing
+    Rotate_log_event into it.
+  */
+  if (log_file.alloced_buffer)
   {
     /*
       We log the whole file name for log file as the user may decide