Re: [edk2-devel] [PATCH] MdePkg/UefiFileHandleLib: Fix potential NULL dereference

["Liming Gao" <liming.gao@intel.com>]

Push @ 1009b59b6525c16724fe2684c344a6359af28b55

>-----Original Message-----
>From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
>Liming Gao
>Sent: Monday, October 21, 2019 11:12 AM
>To: Marvin.Haeuser@outlook.com; devel@edk2.groups.io
>Cc: vit9696@protonmail.com; Kinney, Michael D <michael.d.kinney@intel.com>
>Subject: Re: [edk2-devel] [PATCH] MdePkg/UefiFileHandleLib: Fix potential
>NULL dereference
>
>Reviewed-by: Liming Gao <liming.gao@intel.com>
>
>>-----Original Message-----
>>From: Marvin Häuser [mailto:Marvin.Haeuser@outlook.com]
>>Sent: Sunday, October 20, 2019 8:09 PM
>>To: devel@edk2.groups.io
>>Cc: vit9696@protonmail.com; Kinney, Michael D
>><michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com>
>>Subject: [PATCH] MdePkg/UefiFileHandleLib: Fix potential NULL dereference
>>
>>From: Marvin Haeuser <mhaeuser@outlook.de>
>>
>>REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2293
>>
>>Move the NULL check in FileHandleGetInfo() to directly after the
>>allocation to prevent potential NULL dereferences.
>>
>>Cc: Michael D Kinney <michael.d.kinney@intel.com>
>>Cc: Liming Gao <liming.gao@intel.com>
>>Signed-off-by: Marvin Haeuser <mhaeuser@outlook.de>
>>---
>> MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c | 28 +++++++++++--
>--
>>-----
>> 1 file changed, 15 insertions(+), 13 deletions(-)
>>
>>diff --git a/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
>>b/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
>>index 96913c5c02b8..5dc893833a46 100644
>>--- a/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
>>+++ b/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
>>@@ -68,19 +68,21 @@ FileHandleGetInfo (
>>     // error is expected.  getting size to allocate
>>
>>     //
>>
>>     FileInfo = AllocateZeroPool(FileInfoSize);
>>
>>-    //
>>
>>-    // now get the information
>>
>>-    //
>>
>>-    Status = FileHandle->GetInfo(FileHandle,
>>
>>-                                 &gEfiFileInfoGuid,
>>
>>-                                 &FileInfoSize,
>>
>>-                                 FileInfo);
>>
>>-    //
>>
>>-    // if we got an error free the memory and return NULL
>>
>>-    //
>>
>>-    if (EFI_ERROR(Status) && (FileInfo != NULL)) {
>>
>>-      FreePool(FileInfo);
>>
>>-      FileInfo = NULL;
>>
>>+    if (FileInfo != NULL) {
>>
>>+      //
>>
>>+      // now get the information
>>
>>+      //
>>
>>+      Status = FileHandle->GetInfo(FileHandle,
>>
>>+                                   &gEfiFileInfoGuid,
>>
>>+                                   &FileInfoSize,
>>
>>+                                   FileInfo);
>>
>>+      //
>>
>>+      // if we got an error free the memory and return NULL
>>
>>+      //
>>
>>+      if (EFI_ERROR(Status)) {
>>
>>+        FreePool(FileInfo);
>>
>>+        FileInfo = NULL;
>>
>>+      }
>>
>>     }
>>
>>   }
>>
>>   return (FileInfo);
>>
>>--
>>2.23.0.windows.1
>
>
>