[efi] Check the status code from AllocatePool()

According to the latest UEFI specification (Version 2.8 Errata B)
p. 7.2:

  "Buffer: A pointer to a pointer to the allocated buffer if the call
   succeeds; undefined otherwise."

So implementations are obliged neither to return NULL, if the
allocation fails, nor to preserve the contents of the pointer.

Make the logic more reliable by checking the status code from
AllocatePool() instead of checking the returned pointer for NULL

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
pull/129/head
Ignat Korchagin 2020-07-21 22:27:08 +01:00 committed by Michael Brown
parent a08ee6e722
commit b760523357
1 changed files with 5 additions and 4 deletions

View File

@ -247,16 +247,17 @@ static int efi_snp_hii_append ( struct efi_snp_device *snpdev __unused,
const char *key, const char *value,
wchar_t **results ) {
EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
EFI_STATUS efirc;
size_t len;
void *new;
/* Allocate new string */
len = ( ( *results ? ( wcslen ( *results ) + 1 /* "&" */ ) : 0 ) +
strlen ( key ) + 1 /* "=" */ + strlen ( value ) + 1 /* NUL */ );
bs->AllocatePool ( EfiBootServicesData, ( len * sizeof ( wchar_t ) ),
&new );
if ( ! new )
return -ENOMEM;
if ( ( efirc = bs->AllocatePool ( EfiBootServicesData,
( len * sizeof ( wchar_t ) ),
&new ) ) != 0 )
return -EEFI ( efirc );
/* Populate string */
efi_snprintf ( new, len, "%ls%s%s=%s", ( *results ? *results : L"" ),