From patchwork Thu Apr 28 15:42:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 567475 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 E3ECAC433EF for ; Thu, 28 Apr 2022 15:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349519AbiD1PqW (ORCPT ); Thu, 28 Apr 2022 11:46:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349466AbiD1PqU (ORCPT ); Thu, 28 Apr 2022 11:46:20 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 201BEB8207; Thu, 28 Apr 2022 08:42:58 -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 C12CAB82DAA; Thu, 28 Apr 2022 15:42:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C982EC385BF; Thu, 28 Apr 2022 15:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651160575; bh=tmemQG01tDxaffG/Pfuw0hVRBBqMxYFA4QXgyJ9KyB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tNVbFGWj4w+O8XJzSS3u5R9zNz+eNvMzluHnAROJ8PEHSppWkxC/Kb1EazourJU6V 4Pf1K0SgnT2l+azMe/3RAD14dhoQshgKCeVlL0FfDqoA7B4tVNV8aLs7zAkN33q04u +154IftS0pcbXeIt6+h5JRXfRcpSHmYNhcPmr5JA= From: Greg Kroah-Hartman To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Muchun Song , Mike Kravetz , Axel Rasmussen , David Rientjes , Fam Zheng , "Kirill A . Shutemov" , Lars Persson , Peter Xu , Xiongchun Duan , Zi Yan , Andrew Morton , Linus Torvalds , Greg Kroah-Hartman Subject: [PATCH AUTOSEL 05/14] mm: shmem: fix missing cache flush in shmem_mfill_atomic_pte() Date: Thu, 28 Apr 2022 17:42:13 +0200 Message-Id: <20220428154222.1230793-5-gregkh@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220428154222.1230793-1-gregkh@linuxfoundation.org> References: <20220428154222.1230793-1-gregkh@linuxfoundation.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1949; i=gregkh@linuxfoundation.org; h=from:subject; bh=Zpdi/DUYbYcHJZrH6XatoKk6jiOZB35pe/zLcwmmE6k=; b=owGbwMvMwCRo6H6F97bub03G02pJDElZW+8I7V/+7fotz2mnl0RMZRSeptb7+8HX9sc9WQ8Dz9v+ 4Y/m6IhlYRBkYpAVU2T5so3n6P6KQ4pehranYeawMoEMYeDiFICJvH/GME/XkV/0Z52gvsadlwwHQk K/Z987IsIwT1X64LHvwY/O7N29c9sv8zo+sbrDrQA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Muchun Song commit 19b482c29b6f3805f1d8e93015847b89e2f7f3b1 upstream. userfaultfd calls shmem_mfill_atomic_pte() which does not do any cache flushing for the target page. Then the target page will be mapped to the user space with a different address (user address), which might have an alias issue with the kernel address used to copy the data from the user to. Insert flush_dcache_page() in non-zero-page case. And replace clear_highpage() with clear_user_highpage() which already considers the cache maintenance. Link: https://lkml.kernel.org/r/20220210123058.79206-6-songmuchun@bytedance.com Fixes: 8d1039634206 ("userfaultfd: shmem: add shmem_mfill_zeropage_pte for userfaultfd support") Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Cc: Axel Rasmussen Cc: David Rientjes Cc: Fam Zheng Cc: Kirill A. Shutemov Cc: Lars Persson Cc: Peter Xu Cc: Xiongchun Duan Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/shmem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index a09b29ec2b45..7a46419d331d 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2357,8 +2357,10 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, /* don't free the page */ goto out_unacct_blocks; } + + flush_dcache_page(page); } else { /* ZEROPAGE */ - clear_highpage(page); + clear_user_highpage(page, dst_addr); } } else { page = *pagep;