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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 7B381C43441 for ; Mon, 19 Nov 2018 16:41:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 451B4208E4 for ; Mon, 19 Nov 2018 16:41:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="oqDzAVis" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 451B4208E4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733252AbeKTDFa (ORCPT ); Mon, 19 Nov 2018 22:05:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:38876 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732502AbeKTDF3 (ORCPT ); Mon, 19 Nov 2018 22:05:29 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 C23E52147D; Mon, 19 Nov 2018 16:41:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542645679; bh=zVn+godcIX4KLYKR3jOSq917vwDofMoATu/FdzMhf/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oqDzAVisCWOcRj59csupuMpzFwAQTwOqx4QOQaYLi5oLE0d4ap3yweUmTs/RfEjvO ib6z6yJOrEi4+30ZcUXtrImAo6IxsUO8zYurdWl2dXqivVLc6bFPEBxvM398KgISbb BwDmmRhus+5e2fuB2Osz8y0jWzGZoXnUgzF9WxBw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+3ef5c0d1a5cb0b21e6be@syzkaller.appspotmail.com, Amir Goldstein , Miklos Szeredi Subject: [PATCH 4.18 049/171] ovl: fix recursive oi->lock in ovl_link() Date: Mon, 19 Nov 2018 17:27:25 +0100 Message-Id: <20181119162627.747388652@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162618.909354448@linuxfoundation.org> References: <20181119162618.909354448@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein commit 6cd078702f2f33cb6b19a682de3e9184112f1a46 upstream. linking a non-copied-up file into a non-copied-up parent results in a nested call to mutex_lock_interruptible(&oi->lock). Fix this by copying up target parent before ovl_nlink_start(), same as done in ovl_rename(). ~/unionmount-testsuite$ ./run --ov -s ~/unionmount-testsuite$ ln /mnt/a/foo100 /mnt/a/dir100/ WARNING: possible recursive locking detected -------------------------------------------- ln/1545 is trying to acquire lock: 00000000bcce7c4c (&ovl_i_lock_key[depth]){+.+.}, at: ovl_copy_up_start+0x28/0x7d but task is already holding lock: 0000000026d73d5b (&ovl_i_lock_key[depth]){+.+.}, at: ovl_nlink_start+0x3c/0xc1 [SzM: this seems to be a false positive, but doing the copy-up first is harmless and removes the lockdep splat] Reported-by: syzbot+3ef5c0d1a5cb0b21e6be@syzkaller.appspotmail.com Fixes: 5f8415d6b87e ("ovl: persistent overlay inode nlink for...") Cc: # v4.13 Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi [amir: backport to v4.18] Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/dir.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -665,6 +665,11 @@ static int ovl_link(struct dentry *old, if (err) goto out_drop_write; + err = ovl_copy_up(new->d_parent); + if (err) + goto out_drop_write; + + err = ovl_nlink_start(old, &locked); if (err) goto out_drop_write;