mirror of https://github.com/acidanthera/audk.git
004b811238
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>
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|---|---|---|
| .. | ||
| Application | ||
| DynamicCommand | ||
| Include | ||
| Library | ||
| ShellPkg.dec | ||
| ShellPkg.dsc | ||