From patchwork Mon Oct 12 13:26:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 270208 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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 DC2BAC433DF for ; Mon, 12 Oct 2020 14:05:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EE5D2074D for ; Mon, 12 Oct 2020 14:05:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602511538; bh=ezOUzcrUIiadmFHTCXkiPhveMCAMHY6T5StkAf66SzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VWbYoGmoPukR7Y8XviLJSbF8PKpBIqfgJrXoJeBfReWOblqmRyzAIIERZBMfSqAc7 iKYSIzXKTAJwy29CJucnWjr8m3HDP+8THdIsufw2wm2RexCCddbvER7CGAmzM/vM7Y u/hUZcopJJwxruQhCyVh7NE82JedDRDdXVyliaSI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390971AbgJLOF0 (ORCPT ); Mon, 12 Oct 2020 10:05:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:37732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729949AbgJLNfK (ORCPT ); Mon, 12 Oct 2020 09:35:10 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 769FF221FE; Mon, 12 Oct 2020 13:35:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509710; bh=ezOUzcrUIiadmFHTCXkiPhveMCAMHY6T5StkAf66SzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xKshFr3sbNnBY5Lh6pJ8CWdt9Y3QpaM7LYFWMJaZtJycILkqiKuIHFntDRz26DEE8 x8xz+3JFHcAok5Tta0BFPZft/6kVhsuSv9QpveLfYmsl9oc5RjkS/4t5AGHyPpxHNL //RHYz90LKJzm5cUB+k7cBga0jUokQpX+y3P6ye8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro Subject: [PATCH 4.9 21/54] ep_create_wakeup_source(): dentry name can change under you... Date: Mon, 12 Oct 2020 15:26:43 +0200 Message-Id: <20201012132630.569922401@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132629.585664421@linuxfoundation.org> References: <20201012132629.585664421@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Al Viro commit 3701cb59d892b88d569427586f01491552f377b1 upstream. or get freed, for that matter, if it's a long (separately stored) name. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- fs/eventpoll.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1260,7 +1260,7 @@ static int reverse_path_check(void) static int ep_create_wakeup_source(struct epitem *epi) { - const char *name; + struct name_snapshot n; struct wakeup_source *ws; if (!epi->ep->ws) { @@ -1269,8 +1269,9 @@ static int ep_create_wakeup_source(struc return -ENOMEM; } - name = epi->ffd.file->f_path.dentry->d_name.name; - ws = wakeup_source_register(name); + take_dentry_name_snapshot(&n, epi->ffd.file->f_path.dentry); + ws = wakeup_source_register(n.name); + release_dentry_name_snapshot(&n); if (!ws) return -ENOMEM;