From nobody Mon Feb 9 04:28:58 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 570E6EB64DA for ; Thu, 20 Jul 2023 14:22:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232190AbjGTOWu (ORCPT ); Thu, 20 Jul 2023 10:22:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232187AbjGTOWr (ORCPT ); Thu, 20 Jul 2023 10:22:47 -0400 X-Greylist: delayed 462 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 20 Jul 2023 07:22:45 PDT Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED8782703; Thu, 20 Jul 2023 07:22:44 -0700 (PDT) Received: from [2601:18c:8180:ac39:6e0b:84ff:fee2:98bb] (helo=imladris.surriel.com) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qMUQN-0001k2-2d; Thu, 20 Jul 2023 10:14:35 -0400 Date: Thu, 20 Jul 2023 10:14:31 -0400 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, Mike Rapoport , devicetree@vger.kernel.org, x86@kernel.org, Rob Herring , Juergen Gross , Dave Hansen Subject: [PATCH] mm,ima,kexec: use memblock_free_late from ima_free_kexec_buffer Message-ID: <20230720101431.71640c8a@imladris.surriel.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: riel@surriel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The code calling ima_free_kexec_buffer runs long after the memblock allocator has already been torn down, potentially resulting in a use after free in memblock_isolate_range. With KASAN or KFENCE, this use after free will result in a BUG from the idle task, and a subsequent kernel panic. Switch ima_free_kexec_buffer over to memblock_free_late to avoid that issue. Fixes: fee3ff99bc67 ("powerpc: Move arch independent ima kexec functions to= drivers/of/kexec.c") Cc: stable@kernel.org Signed-off-by: Rik van Riel Suggested-by: Mike Rappoport Acked-by: Rob Herring --- arch/x86/kernel/setup.c | 8 ++------ drivers/of/kexec.c | 3 ++- 2 files changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index fd975a4a5200..aa0df37c1fe7 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -359,15 +359,11 @@ static void __init add_early_ima_buffer(u64 phys_addr) #if defined(CONFIG_HAVE_IMA_KEXEC) && !defined(CONFIG_OF_FLATTREE) int __init ima_free_kexec_buffer(void) { - int rc; - if (!ima_kexec_buffer_size) return -ENOENT; =20 - rc =3D memblock_phys_free(ima_kexec_buffer_phys, - ima_kexec_buffer_size); - if (rc) - return rc; + memblock_free_late(ima_kexec_buffer_phys, + ima_kexec_buffer_size); =20 ima_kexec_buffer_phys =3D 0; ima_kexec_buffer_size =3D 0; diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c index f26d2ba8a371..68278340cecf 100644 --- a/drivers/of/kexec.c +++ b/drivers/of/kexec.c @@ -184,7 +184,8 @@ int __init ima_free_kexec_buffer(void) if (ret) return ret; =20 - return memblock_phys_free(addr, size); + memblock_free_late(addr, size); + return 0; } #endif =20 --=20 2.41.0