diff options
| author | Matthew Garrett <mjg59@google.com> | 2017-08-25 17:50:15 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-26 09:20:33 +0200 |
| commit | ccc829ba3624beb9a703fc995d016b836d9eead8 (patch) | |
| tree | b1791e31decb96c4fad4cd24b6b9dce5a351d2eb /drivers/firmware/efi/Kconfig | |
| parent | Merge branch 'x86/mm' into efi/core, to pick up dependencies (diff) | |
| download | linux-ccc829ba3624beb9a703fc995d016b836d9eead8.tar.xz linux-ccc829ba3624beb9a703fc995d016b836d9eead8.zip | |
efi/libstub: Enable reset attack mitigation
If a machine is reset while secrets are present in RAM, it may be
possible for code executed after the reboot to extract those secrets
from untouched memory. The Trusted Computing Group specified a mechanism
for requesting that the firmware clear all RAM on reset before booting
another OS. This is done by setting the MemoryOverwriteRequestControl
variable at startup. If userspace can ensure that all secrets are
removed as part of a controlled shutdown, it can reset this variable to
0 before triggering a hardware reboot.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170825155019.6740-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware/efi/Kconfig')
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 394db40ed374..2b4c39fdfa91 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -151,6 +151,16 @@ config APPLE_PROPERTIES If unsure, say Y if you have a Mac. Otherwise N. +config RESET_ATTACK_MITIGATION + bool "Reset memory attack mitigation" + depends on EFI_STUB + help + Request that the firmware clear the contents of RAM after a reboot + using the TCG Platform Reset Attack Mitigation specification. This + protects against an attacker forcibly rebooting the system while it + still contains secrets in RAM, booting another OS and extracting the + secrets. + endmenu config UEFI_CPER |