SecurityPkg/DxeImageVerificationHandler: fix retval on memalloc failure

A SECURITY2_FILE_AUTHENTICATION_HANDLER function is not expected to return
EFI_OUT_OF_RESOURCES. We should only return EFI_SUCCESS,
EFI_SECURITY_VIOLATION, or EFI_ACCESS_DENIED.

In case we run out of memory while preparing "SignatureList" for
AddImageExeInfo(), we should simply stick with the EFI_ACCESS_DENIED value
that is already in "Status" -- from just before the "Action" condition --,
and not suppress it with EFI_OUT_OF_RESOURCES.

This patch does not change the control flow in the function, it only
changes the "Status" outcome from API-incompatible error codes to
EFI_ACCESS_DENIED, under some circumstances.

Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2129
Fixes: 570b3d1a7278df29878da87990e8366bd42d0ec5
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200116190705.18816-6-lersek@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
[lersek@redhat.com: push with Mike's R-b due to Chinese New Year
 Holiday: <https://edk2.groups.io/g/devel/message/53429>; msgid
 <d3fbb76dabed4e1987c512c328c82810@intel.com>]

1 files changed, 0 insertions, 2 deletions

diff --git a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
index 5cc82c1b3b..5f09a66bc9 100644
--- a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
+++ b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
@@ -1541,7 +1541,6 @@ Done:
                                  and non-NULL FileBuffer did authenticate, and the platform

                                  policy dictates that the DXE Foundation may execute the image in

                                  FileBuffer.

-  @retval EFI_OUT_RESOURCE       Fail to allocate memory.

   @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and

                                  the platform policy dictates that File should be placed

                                  in the untrusted state. The image has been added to the file

@@ -1862,7 +1861,6 @@ DxeImageVerificationHandler (
     SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;

     SignatureList     = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);

     if (SignatureList == NULL) {

-      Status = EFI_OUT_OF_RESOURCES;

       goto Done;

     }

     SignatureList->SignatureHeaderSize  = 0;