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[edk2,1/1] ArmPlatformPkg/Bds: stop inputting more characters when string is full

Message ID 1393321658-11970-2-git-send-email-ryan.harkin@linaro.org
State Accepted
Commit 7ffa9c616d41956d84b82e3c9792fd87e3d3e1ae
Headers show

Commit Message

Ryan Harkin Feb. 25, 2014, 9:47 a.m. UTC 
If EditHIInputStr() is called, say with a MaxCmdLine of 2, the user is
currently allowed to enter 2 characters.

If the second character is a carriage return/line feed, this is
substituted with a NULL and the function returns.

If the second character is a regular character, the loop terminated and
the function returns.  However, the buffer has not been NULL terminated.

This patch prevents the user from entering a regular character as the
final character and ensures that the only way out of the input is by
pressing ESC or ENTER (or equivalent).

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
---
 ArmPlatformPkg/Bds/BdsHelper.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)
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Patch

diff --git a/ArmPlatformPkg/Bds/BdsHelper.c b/ArmPlatformPkg/Bds/BdsHelper.c
index 3142d85..7f0ef42 100644
--- a/ArmPlatformPkg/Bds/BdsHelper.c
+++ b/ArmPlatformPkg/Bds/BdsHelper.c
@@ -35,7 +35,7 @@  EditHIInputStr (
   Print (CmdLine);
 
   // To prevent a buffer overflow, we only allow to enter (MaxCmdLine-1) characters
-  for (CmdLineIndex = StrLen (CmdLine); CmdLineIndex < MaxCmdLine - 1; ) {
+  for (CmdLineIndex = StrLen (CmdLine); CmdLineIndex < MaxCmdLine; ) {
     Status = gBS->WaitForEvent (1, &gST->ConIn->WaitForKey, &WaitIndex);
     ASSERT_EFI_ERROR (Status);
 
@@ -62,7 +62,7 @@  EditHIInputStr (
       }
     } else if ((Key.ScanCode == SCAN_ESC) || (Char == 0x1B) || (Char == 0x0)) {
       return EFI_INVALID_PARAMETER;
-    } else {
+    } else if (CmdLineIndex < (MaxCmdLine-1)) {
       CmdLine[CmdLineIndex++] = Key.UnicodeChar;
       Print (L"%c", Key.UnicodeChar);
     }
@@ -187,9 +187,7 @@  GetHIInputBoolean (
 
   while(1) {
     Print (L"[y/n] ");
-    // Set MaxCmdLine to 3 to give space for carriage return (when the user
-    // hits enter) and terminal '\0'.
-    Status = GetHIInputStr (CmdBoolean, 3);
+    Status = GetHIInputStr (CmdBoolean, 2);
     if (EFI_ERROR(Status)) {
       return Status;
     } else if ((CmdBoolean[0] == L'y') || (CmdBoolean[0] == L'Y')) {