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MdePkg/PiFirmwareFile: fix undefined behavior in SECTION_SIZE 

RH covscan justifiedly reports that accessing
"EFI_COMMON_SECTION_HEADER.Size", which is of type UINT8[3], through a
(UINT32*), is undefined behavior:

> Error: OVERRUN (CWE-119):
> edk2-89910a39dcfd/OvmfPkg/Sec/SecMain.c:178: overrun-local: Overrunning
> array of 3 bytes at byte offset 3 by dereferencing pointer
> "(UINT32 *)((EFI_COMMON_SECTION_HEADER *)(UINTN)Section)->Size".
> #  176|       Section = (EFI_COMMON_SECTION_HEADER*)(UINTN) CurrentAddress;
> #  177|
> #  178|->     Size = SECTION_SIZE (Section);
> #  179|       if (Size < sizeof (*Section)) {
> #  180|         return EFI_VOLUME_CORRUPTED;

Fix this by accessing the array elements individually.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=1710
Issue: scan-1007.txt
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
This commit is contained in:
Laszlo Ersek 2019-04-12 14:03:23 +02:00
parent d976f09d99
commit fc76bbd94d
1 changed files with 9 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
MdePkg/Include/Pi/PiFirmwareFile.h
View File

@ -480,8 +480,15 @@ typedef struct {
CHAR16 VersionString[1];
} EFI_VERSION_SECTION2;
#define SECTION_SIZE(SectionHeaderPtr) \
((UINT32) (*((UINT32 *) ((EFI_COMMON_SECTION_HEADER *) (UINTN) SectionHeaderPtr)->Size) & 0x00ffffff))
///
/// The argument passed as the SectionHeaderPtr parameter to the SECTION_SIZE()
/// and IS_SECTION2() function-like macros below must not have side effects:
/// SectionHeaderPtr is evaluated multiple times.
///
#define SECTION_SIZE(SectionHeaderPtr) ((UINT32) ( \
(((EFI_COMMON_SECTION_HEADER *) (UINTN) (SectionHeaderPtr))->Size[0] ) | \
(((EFI_COMMON_SECTION_HEADER *) (UINTN) (SectionHeaderPtr))->Size[1] << 8) | \
(((EFI_COMMON_SECTION_HEADER *) (UINTN) (SectionHeaderPtr))->Size[2] << 16)))
#define IS_SECTION2(SectionHeaderPtr) \
(SECTION_SIZE (SectionHeaderPtr) == 0x00ffffff)