| Message ID | 20171104214012.30888-1-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [edk2] MdeModulePkg/SdMmcPciHcDxe: use FreeBuffer not FreePages from DMA buffer | expand |
On 4 November 2017 at 21:40, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > Don't use EFI_PCI_IO_PROTOCOL::FreePages () to free an allocation > created with EFI_PCI_IO_PROTOCOL::AllocatePages (). It is simply > incorrect, but given that it may interfere with IOMMU DMA protection > and/or memory encryption, it could pose a security risk as well. > > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c > index 23faec5e2be0..a6005dd33bce 100644 > --- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c > +++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c > @@ -1009,7 +1009,7 @@ SdMmcPassThruPassThru ( > > Done: > if ((Trb != NULL) && (Trb->AdmaDesc != NULL)) { > - FreePages (Trb->AdmaDesc, Trb->AdmaPages); > + Private->PciIo->FreeBuffer (Private->PciIo, Trb->AdmaPages, Trb->AdmaDesc); Actually, looking a bit deeper, it seems we need to simply call SdMmcFreeTrb () here, otherwise PciIo->Unmap() is never called on the DataMap mapping, which breaks non-coherent DMA (and also coherent bounce buffering DMA) > } > > if (Trb != NULL) { > -- > 2.11.0 > _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c index 23faec5e2be0..a6005dd33bce 100644 --- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c +++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c @@ -1009,7 +1009,7 @@ SdMmcPassThruPassThru ( Done: if ((Trb != NULL) && (Trb->AdmaDesc != NULL)) { - FreePages (Trb->AdmaDesc, Trb->AdmaPages); + Private->PciIo->FreeBuffer (Private->PciIo, Trb->AdmaPages, Trb->AdmaDesc); } if (Trb != NULL) {
Don't use EFI_PCI_IO_PROTOCOL::FreePages () to free an allocation created with EFI_PCI_IO_PROTOCOL::AllocatePages (). It is simply incorrect, but given that it may interfere with IOMMU DMA protection and/or memory encryption, it could pose a security risk as well. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.11.0 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel