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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2022-08-03 14:41:32 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 10:25:05 +0200 |
| commit | 0cbdd73d96335467d8f1edb4284d19d5a70b9f8a (patch) | |
| tree | 74d84810452cdbdb6059bc799b8d7fc22274047b /Documentation | |
| parent | 1f7375a628b3641fb770c15a6f82932f62ed9021 (diff) | |
| download | linux-stable-0cbdd73d96335467d8f1edb4284d19d5a70b9f8a.tar.gz linux-stable-0cbdd73d96335467d8f1edb4284d19d5a70b9f8a.tar.bz2 linux-stable-0cbdd73d96335467d8f1edb4284d19d5a70b9f8a.zip | |
x86/bugs: Add "unknown" reporting for MMIO Stale Data
commit 7df548840c496b0141fb2404b889c346380c2b22 upstream.
Older Intel CPUs that are not in the affected processor list for MMIO
Stale Data vulnerabilities currently report "Not affected" in sysfs,
which may not be correct. Vulnerability status for these older CPUs is
unknown.
Add known-not-affected CPUs to the whitelist. Report "unknown"
mitigation status for CPUs that are not in blacklist, whitelist and also
don't enumerate MSR ARCH_CAPABILITIES bits that reflect hardware
immunity to MMIO Stale Data vulnerabilities.
Mitigation is not deployed when the status is unknown.
[ bp: Massage, fixup. ]
Fixes: 8d50cdf8b834 ("x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data")
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/a932c154772f2121794a5f2eded1a11013114711.1657846269.git.pawan.kumar.gupta@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst b/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst index 9393c50b5afc..c98fd11907cc 100644 --- a/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst +++ b/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst @@ -230,6 +230,20 @@ The possible values in this file are: * - 'Mitigation: Clear CPU buffers' - The processor is vulnerable and the CPU buffer clearing mitigation is enabled. + * - 'Unknown: No mitigations' + - The processor vulnerability status is unknown because it is + out of Servicing period. Mitigation is not attempted. + +Definitions: +------------ + +Servicing period: The process of providing functional and security updates to +Intel processors or platforms, utilizing the Intel Platform Update (IPU) +process or other similar mechanisms. + +End of Servicing Updates (ESU): ESU is the date at which Intel will no +longer provide Servicing, such as through IPU or other similar update +processes. ESU dates will typically be aligned to end of quarter. If the processor is vulnerable then the following information is appended to the above information: |