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=-10.1 required=3.0 tests=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 3ACA2C2BA19 for ; Wed, 15 Apr 2020 12:28:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DACE208FE for ; Wed, 15 Apr 2020 12:28:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586953681; bh=ZwYuWogEoMguMqy8IBBG5/+pe0y6k0fPBiOgbUr18LM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=s6F1lVvMdwcY0dgC6yMWBxwrJXCqtDS4CjoQTaHheGLGywp6vjZHJ0iUQyf35V3Z2 K2y+SU0tPdWqR3sX+NO9t+T0cg4xMuiUk43CgqkyLsoiHTmlRzQJI1Q7wcjZm/8Wwj 9ZnZ/U31LP7FeukM3nkV5C13Af+3nX+hgudptXhE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S369305AbgDOM17 (ORCPT ); Wed, 15 Apr 2020 08:27:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:38538 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409150AbgDOLpO (ORCPT ); Wed, 15 Apr 2020 07:45:14 -0400 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 62B6820775; Wed, 15 Apr 2020 11:45:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951114; bh=ZwYuWogEoMguMqy8IBBG5/+pe0y6k0fPBiOgbUr18LM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W4DJmch7Iz5KctoINZizt+LPAQ9hj38oyY+xmFjoCVe1uKKS9uD6ik2caC6G/Xp9J rNx6lU+23e1XbkoaWb9x8dHVJdlxdoT7YVcwluyWMJmp9hmxwOgfaGYF7DNxdokM7r N4reVlPSpp7zgaDmPxecvcumWHekBoF4TehpH7RI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Domenico Andreoli , Marian Klein , "Darrick J . Wong" , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 28/84] hibernate: Allow uswsusp to write to swap Date: Wed, 15 Apr 2020 07:43:45 -0400 Message-Id: <20200415114442.14166-28-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200415114442.14166-1-sashal@kernel.org> References: <20200415114442.14166-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 d612468ee66bf..34644ce4b5025 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 { @@ -1975,7 +1976,8 @@ 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