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,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 88812C2BBC7 for ; Sat, 11 Apr 2020 12:11:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 627FB21655 for ; Sat, 11 Apr 2020 12:11:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586607061; bh=RFJIfy9W+Q0N57EzhTdawISFExCi5EriOmkwKyuQ5Os=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OVfEj5hswj0IecKXGI+jGFnt/oaxhLUAwSGdC+fXZo+TfBXIQSCetAWaWOleziLoI 9vucV6p64taoxnOaVvQVT8MMHFn8rSZNv6SEOF7QemDVLf2s2EglLLcCH4Jlp3daWc 4whQFgWRAA2RHjfZOBqIkup+J59oS44sB8pJaX6k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726789AbgDKMK5 (ORCPT ); Sat, 11 Apr 2020 08:10:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:42666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726767AbgDKMKx (ORCPT ); Sat, 11 Apr 2020 08:10:53 -0400 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 656EF20787; Sat, 11 Apr 2020 12:10:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586607053; bh=RFJIfy9W+Q0N57EzhTdawISFExCi5EriOmkwKyuQ5Os=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q1/id3wk4cRb/dv3gSGM7bpfA7T7hS0lzJWi+4achyOC6yak3gdM+uT7DkWcrahqw 4lqjt2uYnjlLf/UZ6vjmWyFQm00C3d6E+qSywG6sHnlomaYkZoQBsZl71Q4Ox7bOSO FsIIv1g3mjJpLiN1oTjR2jVA/BQ1DoWcplpwRYQs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guillaume Nault , "David S. Miller" , Will Deacon Subject: [PATCH 4.4 08/29] l2tp: ensure session cant get removed during pppol2tp_session_ioctl() Date: Sat, 11 Apr 2020 14:08:38 +0200 Message-Id: <20200411115409.008779923@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200411115407.651296755@linuxfoundation.org> References: <20200411115407.651296755@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Guillaume Nault commit 57377d63547861919ee634b845c7caa38de4a452 upstream. Holding a reference on session is required before calling pppol2tp_session_ioctl(). The session could get freed while processing the ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket, we also need to take a reference on it in l2tp_session_get(). Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- net/l2tp/l2tp_ppp.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1168,11 +1168,18 @@ static int pppol2tp_tunnel_ioctl(struct if (stats.session_id != 0) { /* resend to session ioctl handler */ struct l2tp_session *session = - l2tp_session_find(sock_net(sk), tunnel, stats.session_id); - if (session != NULL) - err = pppol2tp_session_ioctl(session, cmd, arg); - else + l2tp_session_get(sock_net(sk), tunnel, + stats.session_id, true); + + if (session) { + err = pppol2tp_session_ioctl(session, cmd, + arg); + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + } else { err = -EBADR; + } break; } #ifdef CONFIG_XFRM