In QemuKernelLoaderFsDxeEntrypoint we use FetchBlob to read the content of the kernel/initrd/cmdline from the QEMU fw_cfg interface. Insert a call to VerifyBlob after fetching to allow BlobVerifierLib implementations to add a verification step for these blobs.
This will allow confidential computing OVMF builds to add verification mechanisms for these blobs that originate from an untrusted source (QEMU). The null implementation of BlobVerifierLib does nothing in VerifyBlob, and therefore no functional change is expected. Cc: Laszlo Ersek <ler...@redhat.com> Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org> Cc: Jordan Justen <jordan.l.jus...@intel.com> Cc: Ashish Kalra <ashish.ka...@amd.com> Cc: Brijesh Singh <brijesh.si...@amd.com> Cc: Erdem Aktas <erdemak...@google.com> Cc: James Bottomley <j...@linux.ibm.com> Cc: Jiewen Yao <jiewen....@intel.com> Cc: Min Xu <min.m...@intel.com> Cc: Tom Lendacky <thomas.lenda...@amd.com> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3457 Co-developed-by: James Bottomley <j...@linux.ibm.com> Signed-off-by: James Bottomley <j...@linux.ibm.com> Signed-off-by: Dov Murik <dovmu...@linux.ibm.com> --- OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c b/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c index c7ddd86f5c75..b43330d23b80 100644 --- a/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c +++ b/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c @@ -17,6 +17,7 @@ #include <Guid/QemuKernelLoaderFsMedia.h> #include <Library/BaseLib.h> #include <Library/BaseMemoryLib.h> +#include <Library/BlobVerifierLib.h> #include <Library/DebugLib.h> #include <Library/DevicePathLib.h> #include <Library/MemoryAllocationLib.h> @@ -1039,6 +1040,14 @@ QemuKernelLoaderFsDxeEntrypoint ( if (EFI_ERROR (Status)) { goto FreeBlobs; } + Status = VerifyBlob ( + CurrentBlob->Name, + CurrentBlob->Data, + CurrentBlob->Size + ); + if (EFI_ERROR (Status)) { + goto FreeBlobs; + } mTotalBlobBytes += CurrentBlob->Size; } KernelBlob = &mKernelBlob[KernelBlobTypeKernel]; -- 2.25.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#77509): https://edk2.groups.io/g/devel/message/77509 Mute This Topic: https://groups.io/mt/84016359/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
