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.

sql/field.h

 #ifndef FIELD_INCLUDED
 #define FIELD_INCLUDED
 
-/* Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1802,18 +1802,6 @@ public:
   {
     store_length(ptr, packlength, number);
   }
-
-  /**
-     Return the packed length plus the length of the data. 
-
-     This is used to determine the size of the data plus the 
-     packed length portion in the row data.
-
-     @returns The length in the row plus the size of the data.
-  */
-  uint32 get_packed_size(const uchar *ptr_arg, bool low_byte_first)
-    {return packlength + get_length(ptr_arg, packlength, low_byte_first);}
-
   inline uint32 get_length(uint row_offset= 0)
   { return get_length(ptr+row_offset, this->packlength, table->s->db_low_byte_first); }
   uint32 get_length(const uchar *ptr, uint packlength, bool low_byte_first);

sql/log_event.cc

@@ -18,6 +18,7 @@
 #ifdef MYSQL_CLIENT
 
 #include "sql_priv.h"
+#include "mysqld_error.h"
 
 #else
 
@@ -1945,6 +1946,14 @@ Rows_log_event::print_verbose_one_row(IO_CACHE *file, table_def *td,
     else
     {
       my_b_printf(file, "###   @%d=", i + 1);
+      size_t fsize= td->calc_field_size((uint)i, (uchar*) value);
+      if (value + fsize > m_rows_end)
+      {
+        my_b_printf(file, "***Corrupted replication event was detected."
+                    " Not printing the value***\n");
+        value+= fsize;
+        return 0;
+      }
       size_t size= log_event_print_value(file, value,
                                          td->type(i), td->field_metadata(i),
                                          typestr, sizeof(typestr));

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
 

sql/log_event_old.h

@@ -203,10 +203,8 @@ 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);
-    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
 

sql/rpl_record.cc

-/* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -169,11 +169,15 @@ pack_row(TABLE *table, MY_BITMAP const* cols,
    @param row_data
                   Packed row data
    @param cols    Pointer to bitset describing columns to fill in
-   @param row_end Pointer to variable that will hold the value of the
-                  one-after-end position for the row
+   @param curr_row_end
+                  Pointer to variable that will hold the value of the
+                  one-after-end position for the current row
    @param master_reclength
                   Pointer to variable that will be set to the length of the
                   record on the master side
+   @param row_end
+                  Pointer to variable that will hold the value of the
+                  end position for the data in the row event
 
    @retval 0 No error
 
@@ -185,7 +189,8 @@ int
 unpack_row(Relay_log_info const *rli,
            TABLE *table, uint const colcnt,
            uchar const *const row_data, MY_BITMAP const *cols,
-           uchar const **const row_end, ulong *const master_reclength)
+           uchar const **const current_row_end, ulong *const master_reclength,
+           uchar const *const row_end)
 {
   DBUG_ENTER("unpack_row");
   DBUG_ASSERT(row_data);
@@ -303,6 +308,13 @@ unpack_row(Relay_log_info const *rli,
 #ifndef DBUG_OFF
         uchar const *const old_pack_ptr= pack_ptr;
 #endif
+        uint32 len= tabledef->calc_field_size(i, (uchar *) pack_ptr);
+        if ( pack_ptr + len > row_end )
+        {
+          pack_ptr+= len;
+          my_error(ER_SLAVE_CORRUPT_EVENT, MYF(0));
+          DBUG_RETURN(ER_SLAVE_CORRUPT_EVENT);
+        }
         pack_ptr= f->unpack(f->ptr, pack_ptr, metadata, TRUE);
 	DBUG_PRINT("debug", ("field: %s; metadata: 0x%x;"
                              " pack_ptr: 0x%lx; pack_ptr': 0x%lx; bytes: %d",
@@ -369,6 +381,11 @@ unpack_row(Relay_log_info const *rli,
         uint32 len= tabledef->calc_field_size(i, (uchar *) pack_ptr);
         DBUG_DUMP("field_data", pack_ptr, len);
         pack_ptr+= len;
+        if ( pack_ptr > row_end )
+        {
+          my_error(ER_SLAVE_CORRUPT_EVENT, MYF(0));
+          DBUG_RETURN(ER_SLAVE_CORRUPT_EVENT);
+        }
       }
       null_mask <<= 1;
     }
@@ -382,7 +399,7 @@ unpack_row(Relay_log_info const *rli,
 
   DBUG_DUMP("row_data", row_data, pack_ptr - row_data);
 
-  *row_end = pack_ptr;
+  *current_row_end = pack_ptr;
   if (master_reclength)
   {
     if (*field_ptr)

sql/rpl_record.h

-/* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -32,7 +32,8 @@ size_t pack_row(TABLE* table, MY_BITMAP const* cols,
 int unpack_row(Relay_log_info const *rli,
                TABLE *table, uint const colcnt,
                uchar const *const row_data, MY_BITMAP const *cols,
-               uchar const **const row_end, ulong *const master_reclength);
+               uchar const **const curr_row_end, ulong *const master_reclength,
+               uchar const *const row_end);
 
 // Fill table's record[0] with default values.
 int prepare_record(TABLE *const table, const uint skip, const bool check);

sql/rpl_utility.cc

@@ -186,7 +186,7 @@ int compare_lengths(Field *field, enum_field_types source_type, uint16 metadata)
   DBUG_PRINT("result", ("%d", result));
   DBUG_RETURN(result);
 }
-
+#endif //MYSQL_CLIENT
 /*********************************************************************
  *                   table_def member definitions                    *
  *********************************************************************/
@@ -285,7 +285,6 @@ uint32 table_def::calc_field_size(uint col, uchar *master_data) const
   case MYSQL_TYPE_VARCHAR:
   {
     length= m_field_metadata[col] > 255 ? 2 : 1; // c&p of Field_varstring::data_length()
-    DBUG_ASSERT(uint2korr(master_data) > 0);
     length+= length == 1 ? (uint32) *master_data : uint2korr(master_data);
     break;
   }
@@ -295,17 +294,6 @@ uint32 table_def::calc_field_size(uint col, uchar *master_data) const
   case MYSQL_TYPE_BLOB:
   case MYSQL_TYPE_GEOMETRY:
   {
-#if 1
-    /*
-      BUG#29549: 
-      This is currently broken for NDB, which is using big-endian
-      order when packing length of BLOB. Once they have decided how to
-      fix the issue, we can enable the code below to make sure to
-      always read the length in little-endian order.
-    */
-    Field_blob fb(m_field_metadata[col]);
-    length= fb.get_packed_size(master_data, TRUE);
-#else
     /*
       Compute the length of the data. We cannot use get_length() here
       since it is dependent on the specific table (and also checks the
@@ -331,7 +319,6 @@ uint32 table_def::calc_field_size(uint col, uchar *master_data) const
     }
 
     length+= m_field_metadata[col];
-#endif
     break;
   }
   default:
@@ -340,7 +327,7 @@ uint32 table_def::calc_field_size(uint col, uchar *master_data) const
   return length;
 }
 
-
+#ifndef MYSQL_CLIENT
 /**
  */
 void show_sql_type(enum_field_types type, uint16 metadata, String *str, CHARSET_INFO *field_cs)