From patchwork Tue Aug 2 01:52:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 12934193 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AD63C00144 for ; Tue, 2 Aug 2022 01:54:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235725AbiHBByG (ORCPT ); Mon, 1 Aug 2022 21:54:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235724AbiHBBxa (ORCPT ); Mon, 1 Aug 2022 21:53:30 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E77D24A825 for ; Mon, 1 Aug 2022 18:52:46 -0700 (PDT) Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 271Nwr69024637; Tue, 2 Aug 2022 01:52:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2022-7-12; bh=pEUyimqlBQdSRhoBh66J1F3kNkVuOjq4e7TjLpEwm6s=; b=k0nBE7FXJaCr7ABZQhTgL66pUM0fSxfD09QIY1repqd+y97Mu5IbMVnkZyPORFrxKNi0 B+VIsVMbCL+fK0dh46n0ubnqG3PHXHOaSVU889eHSnnzpdxhZWbOxWNIg8hG/LtbrEst bbweBGpuyvm6j3BZzf5IDByF0yFbmhDlipylouEray+r1IixA/ARYrqVO9x+sgBZCFw1 Z5r8K6plq/Gu9NkWpsoSZGWEskuuOUJ1m+D1Wu37f7ALzWKAWdpNnWno7LZcH5UUdmXX IKVe47H9/4WN1hW4gE0eRblgl9YzudbKMl6oaPMEG+Cs+0ucn0a04rCC9j9roILbg23W Ng== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3hmue2ndu9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Aug 2022 01:52:40 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.5/8.17.1.5) with ESMTP id 271N1PIf000991; Tue, 2 Aug 2022 01:52:40 GMT Received: from pps.reinject (localhost [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3hp57qr3fp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Aug 2022 01:52:37 +0000 Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 2721qb0m025562; Tue, 2 Aug 2022 01:52:37 GMT Received: from ca-common-hq.us.oracle.com (ca-common-hq.us.oracle.com [10.211.9.209]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3hp57qr3fg-1; Tue, 02 Aug 2022 01:52:37 +0000 From: Dai Ngo To: chuck.lever@oracle.com, olga.kornievskaia@gmail.com, jlayton@kernel.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2] NFSD: fix use-after-free on source server when doing inter-server copy Date: Mon, 1 Aug 2022 18:52:34 -0700 Message-Id: <1659405154-21910-1-git-send-email-dai.ngo@oracle.com> X-Mailer: git-send-email 1.8.3.1 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-01_12,2022-08-01_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 spamscore=0 bulkscore=0 suspectscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2208020007 X-Proofpoint-ORIG-GUID: eLWuEUKMf0yTJ4vQ_jxZrL3Ielyq5Y0I X-Proofpoint-GUID: eLWuEUKMf0yTJ4vQ_jxZrL3Ielyq5Y0I Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Use-after-free occurred when the laundromat tried to free expired cpntf_state entry on the s2s_cp_stateids list after inter-server copy completed. The sc_cp_list that the expired copy state was inserted on was already freed. When COPY completes, the Linux client normally sends LOCKU(lock_state x), FREE_STATEID(lock_state x) and CLOSE(open_state y) to the source server. The nfs4_put_stid call from nfsd4_free_stateid cleans up the copy state from the s2s_cp_stateids list before freeing the lock state's stid. However, sometimes the CLOSE was sent before the FREE_STATEID request. When this happens, the nfsd4_close_open_stateid call from nfsd4_close frees all lock states on its st_locks list without cleaning up the copy state on the sc_cp_list list. When the time the FREE_STATEID arrives the server returns BAD_STATEID since the lock state was freed. This causes the use-after-free error to occur when the laundromat tries to free the expired cpntf_state. This patch adds a call to nfs4_free_cpntf_statelist in nfsd4_close_open_stateid to clean up the copy state before calling free_ol_stateid_reaplist to free the lock state's stid on the reaplist. Signed-off-by: Dai Ngo Reviewed-by: Jeff Layton --- fs/nfsd/nfs4state.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 9409a0dc1b76..b99c545f93e4 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1049,6 +1049,9 @@ static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp) static void nfs4_free_deleg(struct nfs4_stid *stid) { + struct nfs4_ol_stateid *stp = openlockstateid(stid); + + WARN_ON(!list_empty(&stp->st_stid.sc_cp_list)); kmem_cache_free(deleg_slab, stid); atomic_long_dec(&num_delegations); } @@ -1463,6 +1466,7 @@ static void nfs4_free_ol_stateid(struct nfs4_stid *stid) release_all_access(stp); if (stp->st_stateowner) nfs4_put_stateowner(stp->st_stateowner); + WARN_ON(!list_empty(&stp->st_stid.sc_cp_list)); kmem_cache_free(stateid_slab, stid); } @@ -6608,6 +6612,7 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s) struct nfs4_client *clp = s->st_stid.sc_client; bool unhashed; LIST_HEAD(reaplist); + struct nfs4_ol_stateid *stp; spin_lock(&clp->cl_lock); unhashed = unhash_open_stateid(s, &reaplist); @@ -6616,6 +6621,8 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s) if (unhashed) put_ol_stateid_locked(s, &reaplist); spin_unlock(&clp->cl_lock); + list_for_each_entry(stp, &reaplist, st_locks) + nfs4_free_cpntf_statelist(clp->net, &stp->st_stid); free_ol_stateid_reaplist(&reaplist); } else { spin_unlock(&clp->cl_lock);