From feb3a0f7d56fd9fd342672069aa736660cea8089 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Fri, 17 Oct 2014 16:50:45 +0100 Subject: [PATCH] [efi] Check for presence of UNDI in NII protocol iPXE itself exposes a dummy NII protocol with no UNDI. Avoid potentially dereferencing a NULL pointer by checking for a non-zero UNDI address. Signed-off-by: Michael Brown --- src/drivers/net/efi/nii.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/drivers/net/efi/nii.c b/src/drivers/net/efi/nii.c index 5b1872ca..56b6340b 100644 --- a/src/drivers/net/efi/nii.c +++ b/src/drivers/net/efi/nii.c @@ -1037,6 +1037,11 @@ static int nii_start ( struct efi_device *efidev ) { /* Locate UNDI and entry point */ nii->undi = ( ( void * ) ( intptr_t ) nii->nii->Id ); + if ( ! nii->undi ) { + DBGC ( nii, "NII %s has no UNDI\n", nii->dev.name ); + rc = -ENODEV; + goto err_no_undi; + } if ( nii->undi->Implementation & PXE_ROMID_IMP_HW_UNDI ) { DBGC ( nii, "NII %s is a mythical hardware UNDI\n", nii->dev.name ); @@ -1085,6 +1090,7 @@ static int nii_start ( struct efi_device *efidev ) { nii_pci_close ( nii ); err_pci_open: err_hw_undi: + err_no_undi: bs->CloseProtocol ( device, &efi_nii31_protocol_guid, efi_image_handle, device ); err_open_protocol: