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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2970C43219 for ; Sun, 9 Oct 2022 21:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231448AbiJIVAp (ORCPT ); Sun, 9 Oct 2022 17:00:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230457AbiJIVAV (ORCPT ); Sun, 9 Oct 2022 17:00:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C1A1F00D; Sun, 9 Oct 2022 13:55:33 -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 737D960CEC; Sun, 9 Oct 2022 20:54:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DAD4C433D6; Sun, 9 Oct 2022 20:54:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665348861; bh=8kvMFNiK8S3+BVnSHaJK1OdWmE6iurGgh/4op3yCUVY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=njzp/eVymv7b+qublnqINWvgV5mg2/pVymgt3neglAIytSjfZLlGkLVupIi1rizpK 77OB+EX0uZbcIKTGf8WIiNOt5Y9gggCvTfIMQ6ZxoL2IG8+D6O8ejLK5YSgz7yud5P convEMh09hENc1QocKBWWBY7zPO8GanC6Xg/x012BSTpSDuVvib1WWFfP73IgQm8+y Q8GzVwHtZoGtYcW7PkNtUh13XD8l5ro406OyC42esayrVpB0Eo/dpyMsodYEkv3jhY 4aTVEJrkJrk7D5t04v4ATYtE1Y9FEvJUTtaGX3wb8z/uY9DsBwwn3g2ENrEpZfWEps 7WwaoM56tuMtA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dai Ngo , Chuck Lever , Sasha Levin , jlayton@kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 10/10] NFSD: fix use-after-free on source server when doing inter-server copy Date: Sun, 9 Oct 2022 16:53:49 -0400 Message-Id: <20221009205350.1203176-10-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221009205350.1203176-1-sashal@kernel.org> References: <20221009205350.1203176-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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 f1b503bec222..665d0eaeb8db 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -843,6 +843,7 @@ static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp) 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); } @@ -1358,6 +1359,7 @@ 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(&stid->sc_cp_list)); kmem_cache_free(stateid_slab, stid); } @@ -6207,6 +6209,7 @@ 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); @@ -6215,6 +6218,8 @@ 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); -- 2.35.1