Re: [edk2-devel] [PATCH v2 4/4] MdeModulePkg/SetupBrowserDxe: Add check for GetBufferForValue()

["Dandan Bi" <dandan.bi@intel.com>]

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Zhang, Shenglei
Sent: Wednesday, October 30, 2019 10:27 PM
To: devel@edk2.groups.io
Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A <hao.a.wu@intel.com>
Subject: [edk2-devel] [PATCH v2 4/4] MdeModulePkg/SetupBrowserDxe: Add check for GetBufferForValue()

The returned value from GetBufferForValue might be NULL, so add a check for that before it is used.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
---
 MdeModulePkg/Universal/SetupBrowserDxe/Expression.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/MdeModulePkg/Universal/SetupBrowserDxe/Expression.c b/MdeModulePkg/Universal/SetupBrowserDxe/Expression.c
index 7f4929c2fcd9..984c68c6bb7a 100644
--- a/MdeModulePkg/Universal/SetupBrowserDxe/Expression.c
+++ b/MdeModulePkg/Universal/SetupBrowserDxe/Expression.c
@@ -1281,7 +1281,12 @@ IfrToUint (
       Result->Type = EFI_IFR_TYPE_UNDEFINED;
       return EFI_SUCCESS;
     }
+
+    if (GetBufferForValue (&Value) == NULL) {
+      return EFI_NOT_FOUND;
+    }

Hi Shenglei,

Before call GetBufferForValue function, has already called function  IsTypeInBuffer to make sure the value must be buffer type.
So GetBufferForValue can not return NULL. 
I think we also can add ASSERT here.

Thanks,
Dandan

     Result->Value.u64 = *(UINT64*) GetBufferForValue (&Value);
+
     if (Value.Type == EFI_IFR_TYPE_BUFFER) {
       FreePool (Value.Buffer);
     }
--
2.18.0.windows.1