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=unavailable 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 56A07C00A89 for ; Tue, 3 Nov 2020 01:26:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1642C2222B for ; Tue, 3 Nov 2020 01:26:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366788; bh=fu1X88HwblEGyDKmT0nXc63ooYPumtIElocBOMRl/WI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Tdo3w0DnYLOuYLU5UEct4gaTpYid2ZYbdn4m6E6j1lXlqrIbC2Orz/sQzcKhLOb4y vNaeVtgN8N907N0hdcDV5+R5SVMwjo/Hpc8SE8qOzes8ggg0vvslEQC7dx1Q3URRGs ucidudSUF+tAs+TrcdOVYiib/P8oleVWiKFhanLk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728394AbgKCB0V (ORCPT ); Mon, 2 Nov 2020 20:26:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:33604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727821AbgKCBTh (ORCPT ); Mon, 2 Nov 2020 20:19:37 -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 563FD2240C; Tue, 3 Nov 2020 01:19:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366376; bh=fu1X88HwblEGyDKmT0nXc63ooYPumtIElocBOMRl/WI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hlnhPEfHidTG1F+twV5KbaEX5v/sY5KLOkrpipmhoBvOs5gQKwtZFDcNbP+9ZSlL9 uyhp2tNmskTvOwHBJBuoJZHNyzhbNIoQM4nM38kljoO7R70egQYRfHJoFVJayrWoBb mQj2GfqlYv95GkUlmSI+1otwun8dtpq7SUQBCB84= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kairui Song , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 5.8 06/29] x86/kexec: Use up-to-dated screen_info copy to fill boot params Date: Mon, 2 Nov 2020 20:19:05 -0500 Message-Id: <20201103011928.183145-6-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201103011928.183145-1-sashal@kernel.org> References: <20201103011928.183145-1-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 db6578d45157e..7d520bada6bfc 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -209,8 +209,7 @@ 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