From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C671C388F2 for ; Tue, 3 Nov 2020 01:21:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01B1D2225E for ; Tue, 3 Nov 2020 01:21:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366496; bh=ZGX1wJ93pGvHummN/+NwNi/8hSAy4jg10Vu8dky7Fes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yGX5PIyPZDB4S8LP/XM4KUAdHBaFtCXux7nc6CbjDdyAD2OIjJpfjA+IkjzelO7A+ pm3UmqDqqbY/EeqpUPBVxL9GvbgYrLaGiczMDIP7MWmuT1kAD7q8u3e7ruxTVhJ6aD FpS3ptGITD9+ok80KGgVUXiFLD8Kwrfco6aSwaSg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728430AbgKCBV1 (ORCPT ); Mon, 2 Nov 2020 20:21:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:36868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728372AbgKCBVW (ORCPT ); Mon, 2 Nov 2020 20:21:22 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 56F2A2245A; Tue, 3 Nov 2020 01:21:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366481; bh=ZGX1wJ93pGvHummN/+NwNi/8hSAy4jg10Vu8dky7Fes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CnhNlE1UAkk4V6bWyclfhZChdV7i0vh8+/Gg8ORXgAxBuWYtR2yfCG9G0OLIjwdjl d2ubj7IVxtueDkij9hMh6CjqxnmTMU6oAZMQKGOYx1Socsfj9qQSCmgycE1x6wf82t FYnO50txot6fcH6LU/x347stMFSMSdpVXJg0qEFo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kairui Song , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.4 2/5] x86/kexec: Use up-to-dated screen_info copy to fill boot params Date: Mon, 2 Nov 2020 20:21:15 -0500 Message-Id: <20201103012119.184049-2-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201103012119.184049-1-sashal@kernel.org> References: <20201103012119.184049-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kairui Song [ Upstream commit afc18069a2cb7ead5f86623a5f3d4ad6e21f940d ] kexec_file_load() currently reuses the old boot_params.screen_info, but if drivers have change the hardware state, boot_param.screen_info could contain invalid info. For example, the video type might be no longer VGA, or the frame buffer address might be changed. If the kexec kernel keeps using the old screen_info, kexec'ed kernel may attempt to write to an invalid framebuffer memory region. There are two screen_info instances globally available, boot_params.screen_info and screen_info. Later one is a copy, and is updated by drivers. So let kexec_file_load use the updated copy. [ mingo: Tidied up the changelog. ] Signed-off-by: Kairui Song Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20201014092429.1415040-2-kasong@redhat.com Signed-off-by: Sasha Levin --- arch/x86/kernel/kexec-bzimage64.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 0bf17576dd2af..299e7fb55f16e 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -212,8 +212,7 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params, params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; /* Copying screen_info will do? */ - memcpy(¶ms->screen_info, &boot_params.screen_info, - sizeof(struct screen_info)); + memcpy(¶ms->screen_info, &screen_info, sizeof(struct screen_info)); /* Fill in memsize later */ params->screen_info.ext_mem_k = 0; -- 2.27.0