From c61690fb76f9a51a8c932d76929b67bd0940febe Mon Sep 17 00:00:00 2001 From: Roy Franz Date: Wed, 24 Sep 2014 11:09:11 +0200 Subject: [PATCH] x86/EFI: fix freeing of uninitialized pointer The only valid response from the LocateHandle() call is EFI_BUFFER_TOO_SMALL, so exit if we get anything else. We pass a 0 size/NULL pointer buffer, so the only other returns we will get is an error. Return right away as there is nothing to do. Also return if there is an error allocating the buffer, as the previous code path also allowed for an undefined pointer to be freed. Signed-off-by: Roy Franz Re-structure the change. Signed-off-by: Jan Beulich --- xen/arch/x86/efi/boot.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/xen/arch/x86/efi/boot.c b/xen/arch/x86/efi/boot.c index 3bdc15820a..6f345929f1 100644 --- a/xen/arch/x86/efi/boot.c +++ b/xen/arch/x86/efi/boot.c @@ -595,11 +595,12 @@ static void __init setup_efi_pci(void) struct efi_pci_rom *last = NULL; status = efi_bs->LocateHandle(ByProtocol, &pci_guid, NULL, &size, NULL); - if ( status == EFI_BUFFER_TOO_SMALL ) - status = efi_bs->AllocatePool(EfiLoaderData, size, (void **)&handles); - if ( !EFI_ERROR(status) ) - status = efi_bs->LocateHandle(ByProtocol, &pci_guid, NULL, &size, - handles); + if ( status != EFI_BUFFER_TOO_SMALL ) + return; + status = efi_bs->AllocatePool(EfiLoaderData, size, (void **)&handles); + if ( EFI_ERROR(status) ) + return; + status = efi_bs->LocateHandle(ByProtocol, &pci_guid, NULL, &size, handles); if ( EFI_ERROR(status) ) size = 0; -- 2.30.2