OvmfPkg/VirtioBlkDxe: Check the return status of unmap data buffer

when "RequestIsWrite" is FALSE -- i.e., the CPU wants data from
the device, we map "Buffer" for VirtioOperationBusMasterWrite. In
this case, checking the return status of

Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, BufferMapping);

is must. If the unmapping fails, then "Buffer" will not contain the
actual data from the device, and we must fail the request with
EFI_DEVICE_ERROR.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
[lersek@redhat.com: fix typos in subject]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Brijesh Singh 2017-08-30 12:28:29 -04:00 committed by Laszlo Ersek
parent 877f4460b3
commit ea8314e440
1 changed files with 8 additions and 1 deletions

View File

@ -260,6 +260,7 @@ SynchronousRequest (
EFI_PHYSICAL_ADDRESS HostStatusDeviceAddress;
EFI_PHYSICAL_ADDRESS RequestDeviceAddress;
EFI_STATUS Status;
EFI_STATUS UnmapStatus;
BlockSize = Dev->BlockIoMedia.BlockSize;
@ -430,7 +431,13 @@ SynchronousRequest (
UnmapDataBuffer:
if (BufferSize > 0) {
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, BufferMapping);
UnmapStatus = Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, BufferMapping);
if (EFI_ERROR (UnmapStatus) && !RequestIsWrite && !EFI_ERROR (Status)) {
//
// Data from the bus master may not reach the caller; fail the request.
//
Status = EFI_DEVICE_ERROR;
}
}
UnmapRequestBuffer: