Bug#17632978 SLAVE CRASHES IF ROW EVENT IS CORRUPTED

(MYSQLBINLOG -V CRASHES WITH THAT BINLOG)

Problem: If slave receives a corrupted row event,
slave server is crashing.

Analysis: When slave is unpacking the row event, it is
not validating the data before applying the event. If the
data is corrupted for eg: the length of a field is wrong,
it could end up reading wrong data leading to a crash.
A similar problem happens when mysqlbinlog tool is used
against a corrupted binlog using '-v' option. Due to -v
option, the tool tries to print the values of all the
fields. Corrupted field length could lead to a crash.

Fix: Before unpacking the field, a verification
will be made on the length. If it falls into the event
range, only then it will be unpacked. Otherwise,
"ER_SLAVE_CORRUPT_EVENT" error will be thrown.
Incase mysqlbinlog -v case, the field value will not be
printed and the processing of the file will be stopped.

sql/field.h:
  Removed a function which is not required anymore
sql/log_event.cc:
  Adding a validation on the field length before
  the tool tries to print the value.
sql/log_event.h:
  Changing unpack_row call according to the new arguments
sql/log_event_old.h:
  Changing unpack_row call according to the new arguments
sql/rpl_record.cc:
  Adding a new argument 'row_end' which tells
  the end position of the complete data in the
  row event. It will be used to do validation
  before doing 'unpack' field.
sql/rpl_record.h:
  Adding a new argument 'row_end' which tells
  the end position of the complete data in the
  row event. It will be used to do validation
  before doing 'unpack' field.
sql/rpl_utility.cc:
  Now calc_field_size() is required for client too.

1 files changed, 2 insertions, 6 deletions

diff --git a/sql/log_event.h b/sql/log_event.h
index fa17b32bef2..460d7244d07 100644
--- a/sql/log_event.h
+++ b/sql/log_event.h
@@ -3732,12 +3732,8 @@ protected:
     DBUG_ASSERT(m_table);
 
     ASSERT_OR_RETURN_ERROR(m_curr_row < m_rows_end, HA_ERR_CORRUPT_EVENT);
-    int const result= ::unpack_row(rli, m_table, m_width, m_curr_row, &m_cols,
-                                   &m_curr_row_end, &m_master_reclength);
-    if (m_curr_row_end > m_rows_end)
-      my_error(ER_SLAVE_CORRUPT_EVENT, MYF(0));
-    ASSERT_OR_RETURN_ERROR(m_curr_row_end <= m_rows_end, HA_ERR_CORRUPT_EVENT);
-    return result;
+    return ::unpack_row(rli, m_table, m_width, m_curr_row, &m_cols,
+                                   &m_curr_row_end, &m_master_reclength, m_rows_end);
   }
 #endif