[SRU OEM-5.14 11/11] x86/speculation/mmio: Print SMT warning
Thadeu Lima de Souza Cascardo
cascardo at canonical.com
Wed Jun 15 12:17:25 UTC 2022
From: Josh Poimboeuf <jpoimboe at kernel.org>
commit 1dc6ff02c8bf77d71b9b5d11cbc9df77cfb28626 upstream
Similar to MDS and TAA, print a warning if SMT is enabled for the MMIO
Stale Data vulnerability.
Signed-off-by: Josh Poimboeuf <jpoimboe at kernel.org>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
CVE-2022-21166
CVE-2022-21123
CVE-2022-21125
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
---
arch/x86/kernel/cpu/bugs.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 3c3e4a466136..2a21046846b6 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1221,6 +1221,7 @@ static void update_mds_branch_idle(void)
#define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n"
#define TAA_MSG_SMT "TAA CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html for more details.\n"
+#define MMIO_MSG_SMT "MMIO Stale Data CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/processor_mmio_stale_data.html for more details.\n"
void cpu_bugs_smt_update(void)
{
@@ -1265,6 +1266,16 @@ void cpu_bugs_smt_update(void)
break;
}
+ switch (mmio_mitigation) {
+ case MMIO_MITIGATION_VERW:
+ case MMIO_MITIGATION_UCODE_NEEDED:
+ if (sched_smt_active())
+ pr_warn_once(MMIO_MSG_SMT);
+ break;
+ case MMIO_MITIGATION_OFF:
+ break;
+ }
+
mutex_unlock(&spec_ctrl_mutex);
}
--
2.34.1
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