efi: Validate UEFI boot variables
authorMatthew Garrett <mjg@redhat.com>
Mon, 30 Apr 2012 20:11:30 +0000 (16:11 -0400)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 30 Apr 2012 22:30:18 +0000 (15:30 -0700)
commitfec6c20b570bcf541e581fc97f2e0cbdb9725b98
tree2c84d6748a2aeff0f98ef5abbcc0144273bb8978
parent41b3254c93acc56adc3c4477fef7c9512d47659e
efi: Validate UEFI boot variables

A common flaw in UEFI systems is a refusal to POST triggered by a malformed
boot variable. Once in this state, machines may only be restored by
reflashing their firmware with an external hardware device. While this is
obviously a firmware bug, the serious nature of the outcome suggests that
operating systems should filter their variable writes in order to prevent
a malicious user from rendering the machine unusable.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/firmware/efivars.c