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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 B185BC55189 for ; Wed, 22 Apr 2020 10:34:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E4332073A for ; Wed, 22 Apr 2020 10:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551654; bh=nkzQYljAqqsLT0KyQ1yxVxy4hdkqt9fzHI0OYpbHm4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PGuxD03EkereA5VnKmCHprj9X4XlxsTpP/iPKY4crJi1ICYw8asNwAX56l1mWt64F p4vx5lBPokehTqeNsO3pZJymHg+ym2kqjxJbrqFoxe+IKeHvhH0HuJLcT/HB8IS8bw ZXFi+MlEidruO0c6nIbOCprilPz5rcSJnLgULieo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731256AbgDVKeM (ORCPT ); Wed, 22 Apr 2020 06:34:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:32778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730370AbgDVKY1 (ORCPT ); Wed, 22 Apr 2020 06:24:27 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 39CED2071E; Wed, 22 Apr 2020 10:24:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551066; bh=nkzQYljAqqsLT0KyQ1yxVxy4hdkqt9fzHI0OYpbHm4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eLoQA0gH+RiORewGmVXUkfXE8uhmsvefVDoHA9BiK6vnisQ1+2U9HaQB+65ru06JS Kc+sQ+nlWF05vlCoo6HdfQnBFOszo2zn0AvGUow+vbhj8D9MPGI4Sc5blibxZyx9ka HkFPvinB5Juv5XpUv3hHS6YTU7QjmlYeM/nVO8HY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Domenico Andreoli , Marian Klein , "Darrick J. Wong" , Sasha Levin Subject: [PATCH 5.6 087/166] hibernate: Allow uswsusp to write to swap Date: Wed, 22 Apr 2020 11:56:54 +0200 Message-Id: <20200422095058.017363119@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095047.669225321@linuxfoundation.org> References: <20200422095047.669225321@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Domenico Andreoli [ Upstream commit 56939e014a6c212b317414faa307029e2e80c3b9 ] It turns out that there is one use case for programs being able to write to swap devices, and that is the userspace hibernation code. Quick fix: disable the S_SWAPFILE check if hibernation is configured. Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files") Reported-by: Domenico Andreoli Reported-by: Marian Klein Signed-off-by: Domenico Andreoli Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin --- fs/block_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 69bf2fb6f7cda..84fe0162ff13e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "internal.h" struct bdev_inode { @@ -2001,7 +2002,8 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) if (bdev_read_only(I_BDEV(bd_inode))) return -EPERM; - if (IS_SWAPFILE(bd_inode)) + /* uswsusp needs write permission to the swap */ + if (IS_SWAPFILE(bd_inode) && !hibernation_available()) return -ETXTBSY; if (!iov_iter_count(from)) -- 2.20.1