MdeModulePkg: Fix use-after-free error in InstallConfigurationTable()

MdeModulePkg: Fix use-after-free error in InstallConfigurationTable()

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=601

When installing configuration table and the original
gDxeCoreST->ConfigurationTable[] buffer happen to be not big enough to
add a new table, the CoreInstallConfigurationTable() enter the branch
of line 113 in InstallConfigurationTable.c to free the old
gDxeCoreST->ConfigurationTable[] buffer and allocate a new bigger one.
The problem happens at line 139 CoreFreePool(), which is to free the
old gDxeCoreST->ConfigurationTable[] buffer. The CoreFreePool()'s
behavior is to free the buffer firstly, then call the
InstallMemoryAttributesTableOnMemoryAllocation (PoolType) to update
the EfiRuntimeServices type memory info, the
CoreInstallConfigurationTable() will be re-entered by CoreFreePool()
in its calling stack, then use-after-free read error will happen at
line 59 of InstallConfigurationTable.c and use-after-free write error
will happen at line 151 and 152 of InstallConfigurationTable.c.

The patch is to update System table to the new table pointer before
calling CoreFreePool() to free the old table.

The case above is in DxeCore, but not in PiSmmCore.
The change in PiSmmCore is to be consistent with DxeCore.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Steven Shi <steven.shi@intel.com>
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Steven Shi <steven.shi@intel.com>