[PATCH v3 6/7] x86/bugs: Fix reporting of LFENCE retpoline
From: David Kaplan
Date: Mon Sep 15 2025 - 09:47:32 EST
The LFENCE retpoline mitigation is not secure but the kernel prints
inconsistent messages about this fact. The dmesg log says 'Mitigation:
LFENCE', implying the system is mitigated. But sysfs reports 'Vulnerable:
LFENCE' implying the system (correctly) is not mitigated.
Fix this by printing a consistent 'Vulnerable: LFENCE' string everywhere
when this mitigation is selected.
Signed-off-by: David Kaplan <david.kaplan@xxxxxxx>
---
arch/x86/kernel/cpu/bugs.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 317c26e08827..1f3a20f6fac0 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2032,7 +2032,7 @@ static void __init spectre_v2_user_apply_mitigation(void)
static const char * const spectre_v2_strings[] = {
[SPECTRE_V2_NONE] = "Vulnerable",
[SPECTRE_V2_RETPOLINE] = "Mitigation: Retpolines",
- [SPECTRE_V2_LFENCE] = "Mitigation: LFENCE",
+ [SPECTRE_V2_LFENCE] = "Vulnerable: LFENCE",
[SPECTRE_V2_EIBRS] = "Mitigation: Enhanced / Automatic IBRS",
[SPECTRE_V2_EIBRS_LFENCE] = "Mitigation: Enhanced / Automatic IBRS + LFENCE",
[SPECTRE_V2_EIBRS_RETPOLINE] = "Mitigation: Enhanced / Automatic IBRS + Retpolines",
@@ -3564,9 +3564,6 @@ static const char *spectre_bhi_state(void)
static ssize_t spectre_v2_show_state(char *buf)
{
- if (spectre_v2_enabled == SPECTRE_V2_LFENCE)
- return sysfs_emit(buf, "Vulnerable: LFENCE\n");
-
if (spectre_v2_enabled == SPECTRE_V2_EIBRS && unprivileged_ebpf_enabled())
return sysfs_emit(buf, "Vulnerable: eIBRS with unprivileged eBPF\n");
--
2.34.1