x86/efi: Fix dummy variable buffer allocation

1. Check for allocation failure
2. Clear the buffer contents, as they may actually be written to flash
3. Don't leak the buffer

Compile-tested only.

[ Tested successfully on my buggy ASUS machine - Matt ]

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This commit is contained in:
Ben Hutchings 2013-06-16 21:27:12 +01:00 committed by Matt Fleming
parent f8b8404337
commit b8cb62f821

View file

@ -1069,7 +1069,10 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
* that by attempting to use more space than is available.
*/
unsigned long dummy_size = remaining_size + 1024;
void *dummy = kmalloc(dummy_size, GFP_ATOMIC);
void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
if (!dummy)
return EFI_OUT_OF_RESOURCES;
status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
EFI_VARIABLE_NON_VOLATILE |
@ -1089,6 +1092,8 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
0, dummy);
}
kfree(dummy);
/*
* The runtime code may now have triggered a garbage collection
* run, so check the variable info again