From nobody Fri Oct 17 10:32:17 2025 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 7BB5FC433FE for ; Wed, 19 Oct 2022 09:28:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233637AbiJSJ2S (ORCPT ); Wed, 19 Oct 2022 05:28:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233399AbiJSJ0v (ORCPT ); Wed, 19 Oct 2022 05:26:51 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D06BE5EEF; Wed, 19 Oct 2022 02:12:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 81F14617DE; Wed, 19 Oct 2022 09:09:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96C7DC433D7; Wed, 19 Oct 2022 09:09:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666170585; bh=+pLaFWlsF+KOAjZAyo/mGe/F2d+gV7atMKM+wOKakCo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ULtxpYMUQqpWgZN1yCm1fmjFImBTTKSairsh4qxnSlEs7p9m/9qhjHvMKDq1axCLf xJ/VntgVV0u+5ce6j3AwCrRv8qmwGHm2CHDQdncfkv8u5TLvewIyuKqMM5NsNqpGHW D844OHitkg7Os3m+6GKgCT+z+eE2JRUX1L2qlaiA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dai Ngo , Chuck Lever , Sasha Levin Subject: [PATCH 6.0 678/862] NFSD: fix use-after-free on source server when doing inter-server copy Date: Wed, 19 Oct 2022 10:32:45 +0200 Message-Id: <20221019083319.933818704@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Dai Ngo [ Upstream commit 019805fea91599b22dfa62ffb29c022f35abeb06 ] 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 Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/nfs4state.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index c5d199d7e6b4..0bc36472f8b7 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1049,6 +1049,7 @@ static struct nfs4_ol_stateid * nfs4_alloc_open_state= id(struct nfs4_client *clp) =20 static void nfs4_free_deleg(struct nfs4_stid *stid) { + WARN_ON(!list_empty(&stid->sc_cp_list)); kmem_cache_free(deleg_slab, stid); atomic_long_dec(&num_delegations); } @@ -1462,6 +1463,7 @@ static void nfs4_free_ol_stateid(struct nfs4_stid *st= id) release_all_access(stp); if (stp->st_stateowner) nfs4_put_stateowner(stp->st_stateowner); + WARN_ON(!list_empty(&stid->sc_cp_list)); kmem_cache_free(stateid_slab, stid); } =20 @@ -6684,6 +6686,7 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_s= tateid *s) struct nfs4_client *clp =3D s->st_stid.sc_client; bool unhashed; LIST_HEAD(reaplist); + struct nfs4_ol_stateid *stp; =20 spin_lock(&clp->cl_lock); unhashed =3D unhash_open_stateid(s, &reaplist); @@ -6692,6 +6695,8 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_s= tateid *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); --=20 2.35.1