[PATCH 0/2] efi_runtime: Don't deref userland addresses

[Matt Fleming]

From: Matt Fleming <matt.fleming at intel.com>

We're currently carrying the following patches in the meta-luv layer of
the Linux UEFI Validation project to fix issues encountered when running
fwts on Intel hardware with the Supervisor Mode Access Prevention (SMAP)
feature.

SMAP causes the efi_runtime driver to fault if it directly dereferences
userland addresses without going through the get_user/put_user()
accessor functions, e.g. when going through two-levels of pointer
indirection. The idea being that, if the kernel is accessing userland
addresses directly, it's a potential exploit attempt.

The correct fix is to simply copy structs containing pointers to an
in-kernel copy and then perform a single level of indirection with the
usual get_user/put_user() accessors.

Colin King kindly requested that I send these patches out. Sorry for the
delay in getting these upstream.

Matt Fleming (1):
  efi_runtime: Don't use get_user() on non-pointer

Pradeep Gaddam (1):
  efi_runtime: Copied the structure from userland locally in kernel
    space

 efi_runtime/efi_runtime.c | 50 ++++++++++++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 20 deletions(-)

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1.9.3