[PATCH 6.17 21/35] x86/bugs: Fix reporting of LFENCE retpoline

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Kaplan <david.kaplan@amd.com>

[ Upstream commit d1cc1baef67ac6c09b74629ca053bf3fb812f7dc ]

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@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250915134706.3201818-1-david.kaplan@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 c6bb8e76eb984..26ece97011fd7 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2052,7 +2052,7 @@ 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",
@@ -3636,9 +3636,6 @@ 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");
 
-- 
2.51.0