From 1fd227dd260792b6d12e2e00f74bbf6b9d90cdaf Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 12 Apr 2019 15:43:21 +0200 Subject: [PATCH] MdePkg/PiFirmwareFile: fix undefined behavior in FFS_FILE_SIZE Accessing "EFI_FFS_FILE_HEADER.Size", which is of type UINT8[3], through a (UINT32*), is undefined behavior. Fix it by accessing the array elements individually. Cc: Liming Gao Cc: Michael D Kinney Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=1710 Signed-off-by: Laszlo Ersek Reviewed-by: Philippe Mathieu-Daude Reviewed-by: Michael D Kinney Reviewed-by: Jordan Justen --- MdePkg/Include/Pi/PiFirmwareFile.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/MdePkg/Include/Pi/PiFirmwareFile.h b/MdePkg/Include/Pi/PiFirmwareFile.h index 05470538de..ec7729e9c3 100644 --- a/MdePkg/Include/Pi/PiFirmwareFile.h +++ b/MdePkg/Include/Pi/PiFirmwareFile.h @@ -179,8 +179,15 @@ typedef struct { #define IS_FFS_FILE2(FfsFileHeaderPtr) \ (((((EFI_FFS_FILE_HEADER *) (UINTN) FfsFileHeaderPtr)->Attributes) & FFS_ATTRIB_LARGE_FILE) == FFS_ATTRIB_LARGE_FILE) -#define FFS_FILE_SIZE(FfsFileHeaderPtr) \ - ((UINT32) (*((UINT32 *) ((EFI_FFS_FILE_HEADER *) (UINTN) FfsFileHeaderPtr)->Size) & 0x00ffffff)) +/// +/// The argument passed as the FfsFileHeaderPtr parameter to the +/// FFS_FILE_SIZE() function-like macro below must not have side effects: +/// FfsFileHeaderPtr is evaluated multiple times. +/// +#define FFS_FILE_SIZE(FfsFileHeaderPtr) ((UINT32) ( \ + (((EFI_FFS_FILE_HEADER *) (UINTN) (FfsFileHeaderPtr))->Size[0] ) | \ + (((EFI_FFS_FILE_HEADER *) (UINTN) (FfsFileHeaderPtr))->Size[1] << 8) | \ + (((EFI_FFS_FILE_HEADER *) (UINTN) (FfsFileHeaderPtr))->Size[2] << 16))) #define FFS_FILE2_SIZE(FfsFileHeaderPtr) \ ((UINT32) (((EFI_FFS_FILE_HEADER2 *) (UINTN) FfsFileHeaderPtr)->ExtendedSize))