arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN

Commit 376133b7edc2 upstream.

We're about to rework the way ASIDs are allocated, switch_mm is
implemented and low-level kernel entry/exit is handled, so keep the
ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting.

It will be re-enabled in a subsequent patch.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 59f47f9dcdcde20e0a20c434f18bcc50c7c824e4)

CVE-2017-5753
CVE-2017-5715
CVE-2017-5754

Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b0066730b78618e5d14a3fa880acb089d5416382..906c08750f54a7d693bf6845b7a08f607993fed9 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -900,6 +900,7 @@ endif
 
 config ARM64_SW_TTBR0_PAN
        bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
+       depends on BROKEN       # Temporary while switch_mm is reworked
        help
          Enabling this option prevents the kernel from accessing
          user-space memory directly by pointing TTBR0_EL1 to a reserved