RH covscan justifiedly reports that accessing "EFI_FFS_FILE_HEADER.Size"
and "EFI_COMMON_SECTION_HEADER.Size", which both are of type UINT8[3],
through (UINT32*), is undefined behavior:
> Error: OVERRUN (CWE-119):
> edk2-89910a39dcfd/OvmfPkg/Sec/SecMain.c:283: overrun-local: Overrunning
> array of 3 bytes at byte offset 3 by dereferencing pointer
> "(UINT32 *)File->Size".
> # 281|
> # 282| File = (EFI_FFS_FILE_HEADER*)(UINTN) CurrentAddress;
> # 283|-> Size = *(UINT32*) File->Size & 0xffffff;
> # 284| if (Size < (sizeof (*File) + sizeof
> (EFI_COMMON_SECTION_HEADER))) {
> # 285| return EFI_VOLUME_CORRUPTED;
>
> Error: OVERRUN (CWE-119):
> edk2-89910a39dcfd/OvmfPkg/Sec/SecMain.c:614: overrun-local: Overrunning
> array of 3 bytes at byte offset 3 by dereferencing pointer
> "(UINT32 *)File->Size".
> # 612|
> # 613| File = (EFI_FFS_FILE_HEADER*)(UINTN) CurrentAddress;
> # 614|-> Size = *(UINT32*) File->Size & 0xffffff;
> # 615| if (Size < sizeof (*File)) {
> # 616| return EFI_NOT_FOUND;
>
> Error: OVERRUN (CWE-119):
> edk2-89910a39dcfd/OvmfPkg/Sec/SecMain.c:639: overrun-local: Overrunning
> array of 3 bytes at byte offset 3 by dereferencing pointer
> "(UINT32 *)Section->Size".
> # 637| Section = (EFI_COMMON_SECTION_HEADER*)(UINTN) CurrentAddress;
> # 638|
> # 639|-> Size = *(UINT32*) Section->Size & 0xffffff;
> # 640| if (Size < sizeof (*Section)) {
> # 641| return EFI_NOT_FOUND;
Fix these by invoking the FFS_FILE_SIZE() and SECTION_SIZE() macros, which
by now have been fixed too.
Cc: Ard Biesheuvel <[email protected]>
Cc: Jordan Justen <[email protected]>
Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=1710
Issue: scan-1008.txt
Issue: scan-1009.txt
Issue: scan-1010.txt
Signed-off-by: Laszlo Ersek <[email protected]>
---
OvmfPkg/Sec/SecMain.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index 18a89c649fd4..3914355cd17b 100644
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -269,17 +269,17 @@ FindFfsFileAndSection (
for (EndOfFile = CurrentAddress + Fv->HeaderLength; ; ) {
CurrentAddress = (EndOfFile + 7) & ~(7ULL);
if (CurrentAddress > EndOfFirmwareVolume) {
return EFI_VOLUME_CORRUPTED;
}
File = (EFI_FFS_FILE_HEADER*)(UINTN) CurrentAddress;
- Size = *(UINT32*) File->Size & 0xffffff;
+ Size = FFS_FILE_SIZE (File);
if (Size < (sizeof (*File) + sizeof (EFI_COMMON_SECTION_HEADER))) {
return EFI_VOLUME_CORRUPTED;
}
EndOfFile = CurrentAddress + Size;
if (EndOfFile > EndOfFirmwareVolume) {
return EFI_VOLUME_CORRUPTED;
}
@@ -600,17 +600,17 @@ FindImageBase (
for (EndOfFile = CurrentAddress + BootFirmwareVolumePtr->HeaderLength; ; ) {
CurrentAddress = (EndOfFile + 7) & 0xfffffffffffffff8ULL;
if (CurrentAddress > EndOfFirmwareVolume) {
return EFI_NOT_FOUND;
}
File = (EFI_FFS_FILE_HEADER*)(UINTN) CurrentAddress;
- Size = *(UINT32*) File->Size & 0xffffff;
+ Size = FFS_FILE_SIZE (File);
if (Size < sizeof (*File)) {
return EFI_NOT_FOUND;
}
EndOfFile = CurrentAddress + Size;
if (EndOfFile > EndOfFirmwareVolume) {
return EFI_NOT_FOUND;
}
@@ -625,17 +625,17 @@ FindImageBase (
//
// Loop through the FFS file sections within the FFS file
//
EndOfSection = (EFI_PHYSICAL_ADDRESS)(UINTN) (File + 1);
for (;;) {
CurrentAddress = (EndOfSection + 3) & 0xfffffffffffffffcULL;
Section = (EFI_COMMON_SECTION_HEADER*)(UINTN) CurrentAddress;
- Size = *(UINT32*) Section->Size & 0xffffff;
+ Size = SECTION_SIZE (Section);
if (Size < sizeof (*Section)) {
return EFI_NOT_FOUND;
}
EndOfSection = CurrentAddress + Size;
if (EndOfSection > EndOfFile) {
return EFI_NOT_FOUND;
}
--
2.19.1.3.g30247aa5d201
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