ShellPkg/CommandLib: avoid NULL derefence and memory leak

Since TianoCore EDK2 commit d65f2cea36d1 ("ShellPkg/CommandLib: Locate
proper UnicodeCollation instance") in edk2 the UEFI Shell crashes if EFI
variable PlatformLang is not defined due to dereferencing gUnicodeCollation
gUnicodeCollation (= NULL) in ShellCommandRegisterCommandName().

Furthermore CommandInit() is leaking PlatformLang if
gUnicodeCollation != NULL.

Close the memory leak and use the first UnicodeCollation instance if
PlatfomLang is not defined.

Fixes: d65f2cea36d1 ("ShellPkg/CommandLib: Locate proper UnicodeCollation
instance")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Zhichao Gao <zhichao.gao@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>

1 files changed, 14 insertions, 6 deletions

diff --git a/ShellPkg/Library/UefiShellCommandLib/UefiShellCommandLib.c b/ShellPkg/Library/UefiShellCommandLib/UefiShellCommandLib.c
index 4635df40bb..826ced30a8 100644
--- a/ShellPkg/Library/UefiShellCommandLib/UefiShellCommandLib.c
+++ b/ShellPkg/Library/UefiShellCommandLib/UefiShellCommandLib.c
@@ -74,12 +74,10 @@ CommandInit(
   EFI_STATUS                      Status;

   CHAR8                           *PlatformLang;

 

-  GetEfiGlobalVariable2 (EFI_PLATFORM_LANG_VARIABLE_NAME, (VOID**)&PlatformLang, NULL);

-  if (PlatformLang == NULL) {

-    return EFI_UNSUPPORTED;

-  }

-

   if (gUnicodeCollation == NULL) {

+

+    GetEfiGlobalVariable2 (EFI_PLATFORM_LANG_VARIABLE_NAME, (VOID**)&PlatformLang, NULL);

+

     Status = gBS->LocateHandleBuffer (

                     ByProtocol,

                     &gEfiUnicodeCollation2ProtocolGuid,

@@ -108,6 +106,14 @@ CommandInit(
       }

 

       //

+      // Without clue provided use the first Unicode Collation2 protocol.

+      //

+      if (PlatformLang == NULL) {

+        gUnicodeCollation = Uc;

+        break;

+      }

+

+      //

       // Find the best matching matching language from the supported languages

       // of Unicode Collation2 protocol.

       //

@@ -126,7 +132,9 @@ CommandInit(
     if (Handles != NULL) {

       FreePool (Handles);

     }

-    FreePool (PlatformLang);

+    if (PlatformLang != NULL) {

+      FreePool (PlatformLang);

+    }

   }

 

   return (gUnicodeCollation == NULL) ? EFI_UNSUPPORTED : EFI_SUCCESS;