audk/ShellPkg/Library
Ruiyu Ni 004b811238 ShellPkg/edit: Fix heap access out-of-bounds
The issue was found when heap guard is turned on.
PrintLib somehow receives a non-null terminated string in var-arg.
When the PrintLib implementation reads the string it keeps
reading because no null-terminator is met, which triggers the page
fault set by the heap guard.

The issue is caused by a bug in FileBufferPrintLine().
When "edit" opens a binary file, in FileBufferPrintLine(),
the Line->Buffer may start with \x00 \x00, but the Line->Size is
larger than MainEditor.ScreenSize.Column, it causes the PrintLine is
set to an empty string by below call:
    StrnCpyS (
      PrintLine, BufLen/sizeof(CHAR16), Buffer,
      MIN(Limit, MainEditor.ScreenSize.Column)
      );
But since Limit (equals to Line->Size) is larger than
MainEditor.ScreenSize.Column, below for-loop doesn't successfully
set the whole PrintLine to all-empty-space.
    for (; Limit < MainEditor.ScreenSize.Column; Limit++) {
      PrintLine[Limit] = L' ';
    }
So after the for-loop, PrintLine is still an empty string.
Later in below call, the PrintLine2 is created based on PrintLine.
    ShellCopySearchAndReplace (
      PrintLine, PrintLine2,
      BufLen * 2, L"%", L"^%", FALSE, FALSE
      );
But due to the implementation of ShellCopySearchAndReplace(),
PrintLine2 is untouched and INVALID_PARAMETER is returned.
Finally an uninitialized string is passed to ShellPrintEx()
which causes the #PF exception.

The fix is to reset Limit to StrLen(PrintLine) before for-loop.
So that PrintLine can be converted from an empty string to a
string containing all spaces.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Jian Wang <jian.j.wang@intel.com>
2018-08-20 14:41:01 +08:00
..
UefiHandleParsingLib ShellPkg: Removing ipf which is no longer supported from edk2. 2018-06-29 16:19:49 +08:00
UefiShellAcpiViewCommandLib ShellPkg/acpi: Fix XCODE5 X64 build failure 2018-08-07 15:24:56 +08:00
UefiShellBcfgCommandLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00
UefiShellCEntryLib ShellPkg: Removing ipf which is no longer supported from edk2. 2018-06-29 16:19:49 +08:00
UefiShellCommandLib ShellPkg: Removing ipf which is no longer supported from edk2. 2018-06-29 16:19:49 +08:00
UefiShellDebug1CommandsLib ShellPkg/edit: Fix heap access out-of-bounds 2018-08-20 14:41:01 +08:00
UefiShellDriver1CommandsLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00
UefiShellInstall1CommandsLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00
UefiShellLevel1CommandsLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00
UefiShellLevel2CommandsLib ShellPkg: Removing ipf which is no longer supported from edk2. 2018-06-29 16:19:49 +08:00
UefiShellLevel3CommandsLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00
UefiShellLib ShellPkg/UefiShellLib: rebase ShellOpenFileByDevicePath() to UefiLib API 2018-08-16 20:02:51 +02:00
UefiShellNetwork1CommandsLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00
UefiShellNetwork2CommandsLib ShellPkg: Clean up source files 2018-06-28 11:19:51 +08:00