Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp3451249pxk; Mon, 5 Oct 2020 09:58:26 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx8S4CeWip8N1ZcKOVlV9EIlcGA8dw7QTeKD0yTEYT/k96XWyeFkSGECon4OeD9p/rRsrkN X-Received: by 2002:aa7:c302:: with SMTP id l2mr640873edq.204.1601917106763; Mon, 05 Oct 2020 09:58:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1601917106; cv=none; d=google.com; s=arc-20160816; b=XnMkzY07hsexjCkK9b9v1OSHkn7Bh+4uDBOFW6J+JKQrjucVIn8xPqOQxcadnIB2Qn cu54X2MPw0pdXWF5qaX2+pgfZgkl96ycl5hj7oZIFgDdf3gYDgEPEwP8ftBK/5/4zjWi mghwE1x+qM1giN2mVdOYnjmokrce8xgqoVATFLrSJMb0uz9+TnwIvA4AA1se74FcXkrT 9LVbafRyFUBu1HZxUPZAZJXWPHCl+L6bpwgixJpJG8RLBtNTKx20bmfrCraUwYS4l3hq 1VnwvHu8sP3zbn+mO8L2OgEDZVwyYnBRzozbDwm1tFpPl93zGRzteLgVWqc0XbQMQa8g bcow== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=g2xzisdFB9/ilFU1w0Bg+4fcuke9B0hzxPRk0dweZqc=; b=XRpb3MBS40sEHXQGVgfy29FHvz8ceeKAaTEDfNoKum4MNbMNtUvy2QdSX9PCCV1JlN ugIOgSs6yZtcEDiQ3jLxNK5Fiw0HvZUzfbzLxrDgrXtiHZtXLKQtdfR6NRjyOz4hbcFB G4ZXqlCNkuGdUQEwIkpxC7QotWZEGS/rZH0mgJ8bFMk2dI6w2n+NSZEAD0rXnsrLAjHg sSiHIWEsK33IS4s2aCQ69/IoIYdpipYV80VucVMjjKxaK+fR/IwRAxJWOvAjBZfRRqSh tdJboHg4Jb1oAZsGkQqnfNr8lG4PPMBHTM3oTUoqb02cOo5qHc6OBB5po/T4hruUhssC SCFA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=E35jNN8J; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id ba12si386312edb.470.2020.10.05.09.58.04; Mon, 05 Oct 2020 09:58:26 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=E35jNN8J; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728634AbgJEPjE (ORCPT + 99 others); Mon, 5 Oct 2020 11:39:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:57092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727786AbgJEPae (ORCPT ); Mon, 5 Oct 2020 11:30:34 -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 8AA982085B; Mon, 5 Oct 2020 15:30:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601911834; bh=ZmMRBbHL+vaDDd8DCdZOxUBmmSvEji9EKw4f1kXPKMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E35jNN8J539RLkMqfUnix3QnMs25/SC0RhXolwi5uME9o8afn0X4M3oJARL+la32p YIC2iJwEepCzWV6DsCAy7YOcQz4GRdAim6UP8sdra5xhELyOdC+Cmq1jOnh1SSzhY9 g6N7b2EeWFvDKv6UmBROF2HHXsS74xR7AoHT6iy8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro Subject: [PATCH 5.4 56/57] ep_create_wakeup_source(): dentry name can change under you... Date: Mon, 5 Oct 2020 17:27:08 +0200 Message-Id: <20201005142112.495231674@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201005142109.796046410@linuxfoundation.org> References: <20201005142109.796046410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -1453,7 +1453,7 @@ 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) { @@ -1462,8 +1462,9 @@ static int ep_create_wakeup_source(struc return -ENOMEM; } - name = epi->ffd.file->f_path.dentry->d_name.name; - ws = wakeup_source_register(NULL, name); + take_dentry_name_snapshot(&n, epi->ffd.file->f_path.dentry); + ws = wakeup_source_register(NULL, n.name.name); + release_dentry_name_snapshot(&n); if (!ws) return -ENOMEM;