From nobody Fri Sep 25 00:40:51 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 EE5632EDD58; Fri, 18 Sep 2026 00:41:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789692114; cv=none; b=YD22sD7dn0osjBzJt3S1BWiJYVwnHX9IDvDnXHauI3UGv7NxXbKUmX5r19kBGzbxQEWIVaMCDUzJ+BloalvnJwvcvQTnWF9NBBgDoBePOJN/QirYlAOTRB0Rheagz/C9YN7Xm8pit/XO46tH6IEvP+kk1ph+9iukuibSyV2gQi8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789692114; c=relaxed/simple; bh=flaE0pWMxEdq3g4ouxXb9ZYh8MBBFueA8eXTx6K5XnI=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=XOVTO758a9wQgHL0NJEC46JRfG441HX8WRENaaYbvK7kINAGwarUNt2sgtz1WndesO6bgwjBbiUgDTXcukb6zQ3QiDp7ZtnS5w7Ug58Z0AeOqQpXcz1rO/4IBAAex0ePjkn8OrsvOPZy3RgWB1S2Syo0/uQ88GYIg3Piuko//wQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=o3RkYK/u; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=1fXaNboY; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="o3RkYK/u"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="1fXaNboY" Date: Fri, 18 Sep 2026 00:41:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1789692110; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fW5VJIywckitCgbfM8/Ncr2rVtPrQWVtBIk5/mlllEw=; b=o3RkYK/uEplrn7a027Prw2Q8l+1355L/ywbTc4YRYHmNWmQ1WNzgbT2x3SKDsyWcHrJekh HfDds+6+X3jHOHO4fL/y8lNY2QBZ2rz/3YolzVvBtoJpTEXSZek49Cfxyj1kq2dS2BOzAu Yf98n5iB4XowL0+vu5KlfEbx/JWoUJzOD/M++VbjoBupx7Xd5Fv/Lb9sPEFGGUWlHM/55l aAAPFacgm0rTSuDWMdgDbubjSj00uKHR6rB2nTVKYNjWZD7MAxGvlKvqPUbaoO4Y8nKid0 C/3AWL8JJ+GML8j2vJXcuiMNHbpLqm4kF/TFV96yuyUvVIQoJmS8jjjm1iOZ2Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1789692110; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fW5VJIywckitCgbfM8/Ncr2rVtPrQWVtBIk5/mlllEw=; b=1fXaNboYl0wCODtPVHVd4oAu/sRJyiCyBZfUF6KDmaM763MEZwEVYflhwNfjlqCrCyPCPQ GSJqkfAfq7IhKaDw== From: "tip-bot2 for Chang S. Bae" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/urgent] x86/microcode/intel: Reject problematic loading on Granite Rapids systems Cc: "Chang S. Bae" , "Borislav Petkov (AMD)" , Dave Hansen , stable@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20260916225939.1144524-1-chang.seok.bae@intel.com> References: <20260916225939.1144524-1-chang.seok.bae@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <178969210882.1720534.495699346053864121.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/urgent branch of tip: Commit-ID: e7d3e2f46dd5a69046e6d95a0f189155a5516b93 Gitweb: https://git.kernel.org/tip/e7d3e2f46dd5a69046e6d95a0f189155a= 5516b93 Author: Chang S. Bae AuthorDate: Wed, 16 Sep 2026 22:59:39=20 Committer: Borislav Petkov (AMD) CommitterDate: Thu, 17 Sep 2026 16:54:20 -07:00 x86/microcode/intel: Reject problematic loading on Granite Rapids systems Microcode updates can usually jump revisions. However, there is an erratum = on Granite Rapids systems. If they "jump over" revision 0x1000405, they result= in an #MC. Avoid it. Signed-off-by: Chang S. Bae Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Dave Hansen Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260916225939.1144524-1-chang.seok.bae@inte= l.com --- arch/x86/kernel/cpu/microcode/intel.c | 26 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/mi= crocode/intel.c index 1142183..9f09d38 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -309,6 +309,26 @@ static void save_microcode_patch(struct microcode_inte= l *patch) pr_err("Unable to allocate microcode memory size: %u\n", size); } =20 +static bool revision_is_safe(struct cpu_signature *sig, u32 rev) +{ + u32 vfm =3D IFM(x86_family(sig->sig), x86_model(sig->sig)); + + /* + * Erratum GNR98 can cause #MCs if "jumping over" revision 0x1000405. + * Avoid the jumps. + */ + if (vfm =3D=3D INTEL_GRANITERAPIDS_X && + x86_stepping(sig->sig) =3D=3D 1 && + sig->pf & 0x95 && + sig->rev < 0x1000405 && + rev > 0x1000405) { + pr_err_once("Erratum GNR98: skipping revision 0x%x.\n", rev); + return false; + } + + return true; +} + /* Scan blob for microcode matching the boot CPUs family, model, stepping = */ static __init struct microcode_intel *scan_microcode(void *data, size_t si= ze, struct ucode_cpu_info *uci, @@ -330,6 +350,9 @@ static __init struct microcode_intel *scan_microcode(vo= id *data, size_t size, if (!intel_find_matching_signature(data, &uci->cpu_sig)) continue; =20 + if (!revision_is_safe(&uci->cpu_sig, mc_header->rev)) + continue; + /* * For saving the early microcode, find the matching revision which * was loaded on the BSP. @@ -878,6 +901,9 @@ static enum ucode_state parse_microcode_blobs(int cpu, = struct iov_iter *iter) if (!intel_find_matching_signature(mc, &uci->cpu_sig)) continue; =20 + if (!revision_is_safe(&uci->cpu_sig, mc_header.rev)) + continue; + is_safe =3D ucode_validate_minrev(&mc_header); if (force_minrev && !is_safe) continue;