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 98F67C43603 for ; Mon, 16 Dec 2019 18:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 704E82082E for ; Mon, 16 Dec 2019 18:39:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576521544; bh=FkDwqSX2U3Zi6u1zSLl0ekZoB6wGScHpf/uAMixefME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kK6it4weIIk6iCQ9RZete/VqcqtAK5SRTD7WFcKFsdJ+CE9xMir1wLf+th8/YeaOL GEnprrf1F1akdU0mBJUl47uRWM9P+oGXBsCruuS9GBUvgcgGB5RSJmd0rszyQ8Ji79 2Yw6CYxix2tUKo4v/ngTqVjnLEVZw3K8GWO/c6+g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729614AbfLPSEJ (ORCPT ); Mon, 16 Dec 2019 13:04:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:41082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729599AbfLPSD7 (ORCPT ); Mon, 16 Dec 2019 13:03:59 -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 324CD20700; Mon, 16 Dec 2019 18:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576519438; bh=FkDwqSX2U3Zi6u1zSLl0ekZoB6wGScHpf/uAMixefME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ly8nJfBubQhbrPehHejxOIlJa44TIdI8hVN/bqs2/hyFfgunnzWGtCgJC2EZT4T42 WZ5/B/0FG4qS7XkAwgd8DMz1EaqR+KoQILRcYW75YVIfSGYF3sISednO4zsvLj+sjS LEcJ/WCv/RiUHO/lDew/jQ0wxM0gx3nYgiJyrEQ0= 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 4.19 049/140] ovl: relax WARN_ON() on rename to self Date: Mon, 16 Dec 2019 18:48:37 +0100 Message-Id: <20191216174802.043464455@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216174747.111154704@linuxfoundation.org> References: <20191216174747.111154704@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 @@ -1174,7 +1174,7 @@ 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;