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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 BF6D4C2BA83 for ; Fri, 14 Feb 2020 16:58:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9477C2082F for ; Fri, 14 Feb 2020 16:58:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581699504; bh=P++HCTpxiCRIcTWNZG9ayqctJBsLbth8OUnjd8D3TW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SixPQj7dpw0Ea68KZiUI9iUmnurK6DWs09Tkz/A62K/jO3qFQYBVz5U3blIUw2J6m ynwzwpyt7s/kEZ5AcXm7YKdYXPqI0Z9htuGSF5kXg5cLibEreLHl23O/cSszDxifW0 5hFSQkg0Zlbrupdekhvb2j6A0dFF52W1TWi1w6c8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404435AbgBNQRV (ORCPT ); Fri, 14 Feb 2020 11:17:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:48536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404431AbgBNQRU (ORCPT ); Fri, 14 Feb 2020 11:17:20 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 69B522469A; Fri, 14 Feb 2020 16:17:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581697040; bh=P++HCTpxiCRIcTWNZG9ayqctJBsLbth8OUnjd8D3TW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LyU1RboRyRSM21GPRp++AC3fiMY6EtVMfaZ3HwaSbFmBe3eBkK1H0Fpjb7UaAX3RT kSy1L6Udr+vpzW1Pn0ObtCLoNDOUEFKe/yQbXG+w98DFw9dyY+Yj4u96sepmn5Cbcr 3fRybk8hRtfOw5A2vtxQXJ49Xf5bqAKaDZwjpzK8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "J. Bruce Fields" , Dan Carpenter , Sasha Levin , linux-nfs@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 003/186] nfsd4: avoid NULL deference on strange COPY compounds Date: Fri, 14 Feb 2020 11:14:12 -0500 Message-Id: <20200214161715.18113-3-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214161715.18113-1-sashal@kernel.org> References: <20200214161715.18113-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: "J. Bruce Fields" [ Upstream commit d781e3df710745fbbaee4eb07fd5b64331a1b175 ] With cross-server COPY we've introduced the possibility that the current or saved filehandle might not have fh_dentry/fh_export filled in, but we missed a place that assumed it was. I think this could be triggered by a compound like: PUTFH(foreign filehandle) GETATTR SAVEFH COPY First, check_if_stalefh_allowed sets no_verify on the first (PUTFH) op. Then op_func = nfsd4_putfh runs and leaves current_fh->fh_export NULL. need_wrongsec_check returns true, since this PUTFH has OP_IS_PUTFH_LIKE set and GETATTR does not have OP_HANDLES_WRONGSEC set. We should probably also consider tightening the checks in check_if_stalefh_allowed and double-checking that we don't assume the filehandle is verified elsewhere in the compound. But I think this fixes the immediate issue. Reported-by: Dan Carpenter Fixes: 4e48f1cccab3 "NFSD: allow inter server COPY to have... " Signed-off-by: J. Bruce Fields Signed-off-by: Sasha Levin --- fs/nfsd/nfs4proc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index ee765abad2efb..be42ea2603683 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1798,7 +1798,8 @@ nfsd4_proc_compound(struct svc_rqst *rqstp) if (op->opdesc->op_flags & OP_CLEAR_STATEID) clear_current_stateid(cstate); - if (need_wrongsec_check(rqstp)) + if (current_fh->fh_export && + need_wrongsec_check(rqstp)) op->status = check_nfsd_access(current_fh->fh_export, rqstp); } encode_op: -- 2.20.1