From f73bada970ae0c687abe2a4ec1aa0bb960c1dfe8 Mon Sep 17 00:00:00 2001 From: Roy Franz Date: Fri, 17 Oct 2014 16:03:50 +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 master commit: c61690fb76f9a51a8c932d76929b67bd0940febe master date: 2014-09-24 11:09:11 +0200 --- 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 68c9abe3ca..7eabcead80 100644 --- a/xen/arch/x86/efi/boot.c +++ b/xen/arch/x86/efi/boot.c @@ -594,11 +594,12 @@ 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;