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=-11.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B74A1C433E1 for ; Thu, 20 Aug 2020 19:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 593F5207DF for ; Thu, 20 Aug 2020 19:39:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fieldses.org header.i=@fieldses.org header.b="QpbwfBHS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728003AbgHTTj4 (ORCPT ); Thu, 20 Aug 2020 15:39:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725977AbgHTTjx (ORCPT ); Thu, 20 Aug 2020 15:39:53 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2000EC061385 for ; Thu, 20 Aug 2020 12:39:52 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 7105267A4; Thu, 20 Aug 2020 15:39:51 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 7105267A4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1597952391; bh=FhwwSoNh5mUaGlybT6mTMVeqrt2rPnd5L0Vo4RyYHSw=; h=Date:From:To:Cc:Subject:From; b=QpbwfBHSlDvgoIqaGoUxILe5I7iHczGkIrW2HYZ2pFFC8lcE5/XVJbRC+Fpl4QPnp WjqdXp08Ilehtt4I4TY5z/9yPpAbEKAuLQDT6WqsRaS+85q7sU+rJ4WXfue+j0XUH0 mjVqtll87VXBnWSHZKeBEIWyFMKJ8jM1bu3wjWjY= Date: Thu, 20 Aug 2020 15:39:51 -0400 From: Bruce Fields To: Chuck Lever Cc: Linux NFS Mailing List Subject: [PATCH] nfsd: fix oops on mixed NFSv4/NFSv3 client access Message-ID: <20200820193951.GA28555@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: "J. Bruce Fields" If an NFSv2/v3 client breaks an NFSv4 client's delegation, it will hit a NULL dereference in nfsd_breaker_owns_lease(). Easily reproduceable with for example mount -overs=4.2 server:/export /mnt/ sleep 1h Fixes: 28df3d1539de50 ("nfsd: clients don't need to break their own delegations") Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 2 ++ 1 file changed, 2 insertions(+) Oops, I've had this sitting around a couple weeks but I must have forgotten to send it in. This is needed for 5.9. diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 4b70657385f2..0e5302f6df52 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4598,6 +4598,8 @@ static bool nfsd_breaker_owns_lease(struct file_lock *fl) if (!i_am_nfsd()) return NULL; rqst = kthread_data(current); + if (!rqst->rq_lease_breaker) + return NULL; clp = *(rqst->rq_lease_breaker); return dl->dl_stid.sc_client == clp; } -- 2.26.2