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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 83609C2D0C3 for ; Mon, 16 Dec 2019 17:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D51920733 for ; Mon, 16 Dec 2019 17:58:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576519103; bh=cts9hQU6RDSllwnvrD8+2cVbraLSzWAdx02sFOkz9fY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=t4MUabtTCL2gwswvYerOIEN7tQvLAQSlWuQBROuxL7fpqkwuQtR2lkS9g5EDmxsO5 1vQAcE6MU19DpXugauicBmKVQed4m31mWUm5CsRDgJ0Pr1fRUsSbniXmk1oYS+ny48 xUvn89JI+ziVzpfqrT8mMgkS1XzDVmxYDhZ6CMg4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727800AbfLPR6W (ORCPT ); Mon, 16 Dec 2019 12:58:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:57972 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726795AbfLPR6S (ORCPT ); Mon, 16 Dec 2019 12:58:18 -0500 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 899FB205ED; Mon, 16 Dec 2019 17:58:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576519098; bh=cts9hQU6RDSllwnvrD8+2cVbraLSzWAdx02sFOkz9fY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R/FMrPnRjlmRjpKusoTb6bTqBNn9hmy4Kqm8Q1NWRusUzdj9Ba11WNA+7Gp1+dRR+ Jb0qdGRCtq7HQ5TBmkqWOJun8PO2A4Gwmy1HgyxNNFgTNwQ8uOgAvXu3RY/1Q87C35 LiIqB7MNzKP9xnbL0HAXnbfy/UGZAIMGW62WhKuc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+bb1836a212e69f8e201a@syzkaller.appspotmail.com, Amir Goldstein , Miklos Szeredi Subject: [PATCH 4.14 195/267] ovl: relax WARN_ON() on rename to self Date: Mon, 16 Dec 2019 18:48:41 +0100 Message-Id: <20191216174913.208905465@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216174848.701533383@linuxfoundation.org> References: <20191216174848.701533383@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: Amir Goldstein commit 6889ee5a53b8d969aa542047f5ac8acdc0e79a91 upstream. In ovl_rename(), if new upper is hardlinked to old upper underneath overlayfs before upper dirs are locked, user will get an ESTALE error and a WARN_ON will be printed. Changes to underlying layers while overlayfs is mounted may result in unexpected behavior, but it shouldn't crash the kernel and it shouldn't trigger WARN_ON() either, so relax this WARN_ON(). Reported-by: syzbot+bb1836a212e69f8e201a@syzkaller.appspotmail.com Fixes: 804032fabb3b ("ovl: don't check rename to self") Cc: # v4.9+ Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/dir.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -1042,7 +1042,7 @@ static int ovl_rename(struct inode *oldd if (newdentry == trap) goto out_dput; - if (WARN_ON(olddentry->d_inode == newdentry->d_inode)) + if (olddentry->d_inode == newdentry->d_inode) goto out_dput; err = 0;