From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1679334C15F; Fri, 31 Oct 2025 14:06:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761919568; cv=none; b=MFbsGjTEXoLZj1lr01UFRnEbDv8uFnm4zP84hgHIOO7YFr/f7kLoQJVeVcsENq/BZFd80lE13NG0PkR7KM04nt45Por2xWR+d05/L3OnNgaQKyPEOCANxvN3SdR2GUzXQyOHZIK19gHlaWX+tOnc+eiDTGRQpYoi+n6fAFj91g4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761919568; c=relaxed/simple; bh=R3U1CZsV3E7iXvl5hp4K0pLmZnlO5WEOhEw1FilNt5g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VIYGb9gKoqGw4StuC/BZSvEpwEIpbEJygx80YQElEQTdZ6otV34wsRxCGI/HeEVpGiAYOhQjz8CzmXrV/vadaXnjuaDQlqQg+U8dTKAZKfdtwteQk8XWDVtBNMB+oZag8sOc6TPnzzMOoubTY5rXKB+QRjmxzCWs0TaqknouOGM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DIHUAQlV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DIHUAQlV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F15AC4CEE7; Fri, 31 Oct 2025 14:06:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761919567; bh=R3U1CZsV3E7iXvl5hp4K0pLmZnlO5WEOhEw1FilNt5g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DIHUAQlVoE2UqhRBHqiIhEC+8jrUeNHDeSPjXPP7cHklJG9suTJsvWQJOE8mIrAod pBZ6xS1+gwi0ozfaQBRZdKpCuSQprUj6VzhW0iwpHPnifoYDz5Rzsp39qTU0Mde6aD oPsiIRS/NLM4Tv5By+H1+tDfPxG4xQATWROdFLPU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Kaplan , "Borislav Petkov (AMD)" , Sasha Levin Subject: [PATCH 6.17 21/35] x86/bugs: Fix reporting of LFENCE retpoline Date: Fri, 31 Oct 2025 15:01:29 +0100 Message-ID: <20251031140044.074512673@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251031140043.564670400@linuxfoundation.org> References: <20251031140043.564670400@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Kaplan [ 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 Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/20250915134706.3201818-1-david.kaplan@amd.com Signed-off-by: Sasha Levin --- 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