Patch "powerpc/pseries: Restore default security feature flags on setup" has been added to the 4.9-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2018-06-02 13:37:19
This is a note to let you know that I've just added the patch titled
powerpc/pseries: Restore default security feature flags on setup
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-pseries-restore-default-security-feature-flags-on-setup.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.
From foo@baz Sat Jun 2 15:29:05 CEST 2018
From: Michael Ellerman <mpe@ellerman.id.au> Date: Sat, 2 Jun 2018 21:09:06 +1000 Subject: powerpc/pseries: Restore default security feature flags on setup To: gregkh@linuxfoundation.org Cc: stable@vger.kernel.org, linuxppc-dev@ozlabs.org Message-ID: [ref] From: Mauricio Faria de Oliveira <redacted> commit 6232774f1599028a15418179d17f7df47ede770a upstream. After migration the security feature flags might have changed (e.g., destination system with unpatched firmware), but some flags are not set/clear again in init_cpu_char_feature_flags() because it assumes the security flags to be the defaults. Additionally, if the H_GET_CPU_CHARACTERISTICS hypercall fails then init_cpu_char_feature_flags() does not run again, which potentially might leave the system in an insecure or sub-optimal configuration. So, just restore the security feature flags to the defaults assumed by init_cpu_char_feature_flags() so it can set/clear them correctly, and to ensure safe settings are in place in case the hypercall fail. Fixes: f636c14790ea ("powerpc/pseries: Set or clear security feature flags") Depends-on: 19887d6a28e2 ("powerpc: Move default security feature flags") Signed-off-by: Mauricio Faria de Oliveira <redacted> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/powerpc/platforms/pseries/setup.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c@@ -453,6 +453,10 @@ static void __init find_and_init_phbs(vo static void init_cpu_char_feature_flags(struct h_cpu_char_result *result) { + /* + * The features below are disabled by default, so we instead look to see + * if firmware has *enabled* them, and set them if so. + */ if (result->character & H_CPU_CHAR_SPEC_BAR_ORI31) security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
@@ -492,6 +496,13 @@ void pseries_setup_rfi_flush(void) bool enable; long rc; + /* + * Set features to the defaults assumed by init_cpu_char_feature_flags() + * so it can set/clear again any features that might have changed after + * migration, and in case the hypercall fails and it is not even called. + */ + powerpc_security_features = SEC_FTR_DEFAULT; + rc = plpar_get_cpu_characteristics(&result); if (rc == H_SUCCESS) init_cpu_char_feature_flags(&result);
Patches currently in stable-queue which might be from mpe@ellerman.id.au are queue-4.9/powerpc-64s-clear-pcr-on-boot.patch queue-4.9/powerpc-rfi-flush-differentiate-enabled-and-patched-flush-types.patch queue-4.9/powerpc-64s-fix-section-mismatch-warnings-from-setup_rfi_flush.patch queue-4.9/powerpc-pseries-fix-clearing-of-security-feature-flags.patch queue-4.9/powerpc-powernv-set-or-clear-security-feature-flags.patch queue-4.9/powerpc-64s-move-cpu_show_meltdown.patch queue-4.9/powerpc-rfi-flush-call-setup_rfi_flush-after-lpm-migration.patch queue-4.9/powerpc-pseries-set-or-clear-security-feature-flags.patch queue-4.9/powerpc-rfi-flush-make-it-possible-to-call-setup_rfi_flush-again.patch queue-4.9/powerpc-move-default-security-feature-flags.patch queue-4.9/powerpc-powernv-use-the-security-flags-in-pnv_setup_rfi_flush.patch queue-4.9/powerpc-add-security-feature-flags-for-spectre-meltdown.patch queue-4.9/powerpc-pseries-use-the-security-flags-in-pseries_setup_rfi_flush.patch queue-4.9/powerpc-64s-enhance-the-information-in-cpu_show_meltdown.patch queue-4.9/powerpc-rfi-flush-move-out-of-hardlockup_detector-ifdef.patch queue-4.9/powerpc-rfi-flush-always-enable-fallback-flush-on-pseries.patch queue-4.9/powerpc-rfi-flush-move-the-logic-to-avoid-a-redo-into-the-debugfs-code.patch queue-4.9/powerpc-pseries-restore-default-security-feature-flags-on-setup.patch queue-4.9/powerpc-pseries-add-new-h_get_cpu_characteristics-flags.patch queue-4.9/powerpc-64s-add-support-for-a-store-forwarding-barrier-at-kernel-entry-exit.patch queue-4.9/powerpc-64s-wire-up-cpu_show_spectre_v1.patch queue-4.9/powerpc-powernv-support-firmware-disable-of-rfi-flush.patch queue-4.9/powerpc-pseries-support-firmware-disable-of-rfi-flush.patch queue-4.9/powerpc-64s-wire-up-cpu_show_spectre_v2.patch