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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 31144C433ED for ; Mon, 5 Apr 2021 08:57:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBA4C61245 for ; Mon, 5 Apr 2021 08:57:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233384AbhDEI5y (ORCPT ); Mon, 5 Apr 2021 04:57:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:37022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233232AbhDEI5c (ORCPT ); Mon, 5 Apr 2021 04:57:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A1CEE61393; Mon, 5 Apr 2021 08:57:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617613047; bh=Zna8MsVGd8jIF5ImYQKHoirKHkeAX+SNgNmY9pwAG/0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XgGo990j8xZQb0E8mUMdOz5W9Xr7C7+IPl7cRPp85rWKMu4KS1Hyz+Os4Wb4jox7o b1i2QRTF44D/oGmsfgtvN/bMHBgiS1/Nwx2RUbBlD85v+Df4eovYYe84+9RoJUUz4c RNQ4ksR3A3PBYXW3Dxn1qZ1xSnptv3ptaihYuqS8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "J. Bruce Fields" , Chuck Lever , Sasha Levin Subject: [PATCH 4.9 04/35] rpc: fix NULL dereference on kmalloc failure Date: Mon, 5 Apr 2021 10:53:39 +0200 Message-Id: <20210405085019.010467008@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210405085018.871387942@linuxfoundation.org> References: <20210405085018.871387942@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: J. Bruce Fields [ Upstream commit 0ddc942394013f08992fc379ca04cffacbbe3dae ] I think this is unlikely but possible: svc_authenticate sets rq_authop and calls svcauth_gss_accept. The kmalloc(sizeof(*svcdata), GFP_KERNEL) fails, leaving rq_auth_data NULL, and returning SVC_DENIED. This causes svc_process_common to go to err_bad_auth, and eventually call svc_authorise. That calls ->release == svcauth_gss_release, which tries to dereference rq_auth_data. Signed-off-by: J. Bruce Fields Link: https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- net/sunrpc/auth_gss/svcauth_gss.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index fd897d900d12..85ad23d9a8a9 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -1705,11 +1705,14 @@ static int svcauth_gss_release(struct svc_rqst *rqstp) { struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; - struct rpc_gss_wire_cred *gc = &gsd->clcred; + struct rpc_gss_wire_cred *gc; struct xdr_buf *resbuf = &rqstp->rq_res; int stat = -EINVAL; struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id); + if (!gsd) + goto out; + gc = &gsd->clcred; if (gc->gc_proc != RPC_GSS_PROC_DATA) goto out; /* Release can be called twice, but we only wrap once. */ @@ -1750,10 +1753,10 @@ out_err: if (rqstp->rq_cred.cr_group_info) put_group_info(rqstp->rq_cred.cr_group_info); rqstp->rq_cred.cr_group_info = NULL; - if (gsd->rsci) + if (gsd && gsd->rsci) { cache_put(&gsd->rsci->h, sn->rsc_cache); - gsd->rsci = NULL; - + gsd->rsci = NULL; + } return stat; } -- 2.30.1