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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A157C433FE for ; Mon, 3 Oct 2022 07:13:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229914AbiJCHN3 (ORCPT ); Mon, 3 Oct 2022 03:13:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229872AbiJCHMs (ORCPT ); Mon, 3 Oct 2022 03:12:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F373C422DE; Mon, 3 Oct 2022 00:12:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C9C0DB80E66; Mon, 3 Oct 2022 07:12:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26661C433D7; Mon, 3 Oct 2022 07:12:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664781153; bh=HEpb4eCnReJMMkUUurl5+sAXCcIdPcGKHFpFJgHUXuE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A7VHn6wJuzbHIT0fLPq5DsRK09sUehxYm9eB7yK1y8flFqm3SpQxkgBA9voukNghG Wr1I8jgv8fdp/iZ84rTKw5BDFlEOBLe2N0X4m8k30ErzRyu6rz3K5ZczMdTx/tK0sw kqsfwXFNulLLQwLpUT2bu/TGWcvqUig+3QgAYGKw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Menzel , Jarkko Sakkinen , Dave Hansen , Reinette Chatre Subject: [PATCH 5.19 017/101] x86/sgx: Do not fail on incomplete sanitization on premature stop of ksgxd Date: Mon, 3 Oct 2022 09:10:13 +0200 Message-Id: <20221003070724.928405585@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221003070724.490989164@linuxfoundation.org> References: <20221003070724.490989164@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jarkko Sakkinen commit 133e049a3f8c91b175029fb6a59b6039d5e79cba upstream. Unsanitized pages trigger WARN_ON() unconditionally, which can panic the whole computer, if /proc/sys/kernel/panic_on_warn is set. In sgx_init(), if misc_register() fails or misc_register() succeeds but neither sgx_drv_init() nor sgx_vepc_init() succeeds, then ksgxd will be prematurely stopped. This may leave unsanitized pages, which will result a false warning. Refine __sgx_sanitize_pages() to return: 1. Zero when the sanitization process is complete or ksgxd has been requested to stop. 2. The number of unsanitized pages otherwise. Fixes: 51ab30eb2ad4 ("x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list") Reported-by: Paul Menzel Signed-off-by: Jarkko Sakkinen Signed-off-by: Dave Hansen Reviewed-by: Reinette Chatre Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-sgx/20220825051827.246698-1-jarkko@kernel.org/T/#u Link: https://lkml.kernel.org/r/20220906000221.34286-2-jarkko@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/sgx/main.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -49,9 +49,13 @@ static LIST_HEAD(sgx_dirty_page_list); * Reset post-kexec EPC pages to the uninitialized state. The pages are removed * from the input list, and made available for the page allocator. SECS pages * prepending their children in the input list are left intact. + * + * Return 0 when sanitization was successful or kthread was stopped, and the + * number of unsanitized pages otherwise. */ -static void __sgx_sanitize_pages(struct list_head *dirty_page_list) +static unsigned long __sgx_sanitize_pages(struct list_head *dirty_page_list) { + unsigned long left_dirty = 0; struct sgx_epc_page *page; LIST_HEAD(dirty); int ret; @@ -59,7 +63,7 @@ static void __sgx_sanitize_pages(struct /* dirty_page_list is thread-local, no need for a lock: */ while (!list_empty(dirty_page_list)) { if (kthread_should_stop()) - return; + return 0; page = list_first_entry(dirty_page_list, struct sgx_epc_page, list); @@ -92,12 +96,14 @@ static void __sgx_sanitize_pages(struct } else { /* The page is not yet clean - move to the dirty list. */ list_move_tail(&page->list, &dirty); + left_dirty++; } cond_resched(); } list_splice(&dirty, dirty_page_list); + return left_dirty; } static bool sgx_reclaimer_age(struct sgx_epc_page *epc_page) @@ -440,10 +446,7 @@ static int ksgxd(void *p) * required for SECS pages, whose child pages blocked EREMOVE. */ __sgx_sanitize_pages(&sgx_dirty_page_list); - __sgx_sanitize_pages(&sgx_dirty_page_list); - - /* sanity check: */ - WARN_ON(!list_empty(&sgx_dirty_page_list)); + WARN_ON(__sgx_sanitize_pages(&sgx_dirty_page_list)); while (!kthread_should_stop()) { if (try_to_freeze())