From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793818473; b=QfoFO/Ez9HLMm51PH9qDIlpHvOLg/KZCWaRwAcZeuDmJFsWtYYJ4pjFF7H9416KSeJRZ Axw6P5mDSXMa+S78Q2xrlgEiiOVD+FivJOSI5FhPimPaAD4Yk10NHiiR2jhjOD3ogzVfw 6iBRPU4CWbSnSfQ8eCjzmreKrhkAnBFvle9C1vSDqOmq7EIRGmmKVhT6bPoR481gpotp1 Fwk/sfG5wmg6b1uIWvcbw9JsnBpoZZG/1LfVE5wUCftkIaHr9ZGK2zUg/dNSaIOFtDGSk lLfcyr513+ylRTe9lLA8624W72J11UR54M9gQbk0D2vYhWMuHfw9Wwm0FQsra3j4e3Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793818473; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=V8h6GmAKTc8z4U+KPI5cd5X6qeIHfBNbKkx2u7PvJ6o=; b=tb5jVKXS+TbwQDzqVu0TcADcX+m6ROmMSpFZ3G55VUKxSVK8kWq23nCYThHa54AYvsZn Odtd+VLeJt+NnGlr72ChR42T8vsVWy223vZn7C2d+QJLJeaA7qMQmo/IxANqd8aVsKiz6 LOYJUO2AnQos4VYg+yf+aAt6xmFLddnm+NSmHgDDURanX5KgRWCcQMmbB6rXwz8iaRZqz eVE3tzkikkWQoce2GAEkJAWrtcCxOtjkOd8JX6rVXinIjGMjVxAUOD90Px5ffIsrOB2Ui 8HrVlsi/o386spc2NXWnznXAqaLnheT1Bgih5G9TKgWI39yiSadxaraS6V2Pdi7HGzg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=QlAzY9cT; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AEC046083630 for ; Wed, 4 Nov 2026 18:54:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=QlAzY9cT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04A4B1F00A25; Wed, 4 Nov 2026 18:54:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793818472; bh=V8h6GmAKTc8z4U+KPI5cd5X6qeIHfBNbKkx2u7PvJ6o=; h=Subject:To:Cc:From:Date; b=QlAzY9cTX8fjDWRuDipzSBGZiG1uhpW2AGrMjZRv5vmhdoOZL6kUK4+l5mu3MEIS7 BHfNPAHPuJjGFusOKw2ECi2vM32AHO0mWScjVYlLA6Zy1zX40pPs0+ocy2khc1BKmE mSdF+yH5wpkg1nm01MSZWGtfRS/I9NAs+E5Zf2AM= Subject: FAILED: patch "[PATCH] NFSD: stop registering with rpcbind after a failure in" failed to apply to 6.18-stable tree To: jlayton@kernel.org,cel@kernel.org,okorniev@redhat.com Cc: From: Date: Wed, 04 Nov 2026 13:54:24 -0500 Message-ID: <2026110424-scope-designed-5ca1@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x bf0f3a37e6ccb78ae80cc6eb2edde4f033c7574c # git commit -s git send-email --to '' --in-reply-to '2026110424-scope-designed-5ca1@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From bf0f3a37e6ccb78ae80cc6eb2edde4f033c7574c Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 1 Sep 2026 09:39:48 -0400 Subject: [PATCH] NFSD: stop registering with rpcbind after a failure in listener_set nfsd_nl_listener_set_doit() calls svc_xprt_create_from_sa() once for each requested listener and passes flags of 0, so every listener registers with rpcbind on its own. A rpcbind that accepts the connection and never replies therefore costs one timeout for each entry. With the cap of 1024 entries the request can hold nfsd_mutex for about 34 minutes, which is roughly 17 times the hung-task threshold. One failure is enough to know that the next call will not fare better. Read svc_rpcb_failure_count() before the create loop, and pass SVC_SOCK_ANONYMOUS for the rest of the request once the count moves. Fixes: 16a471177496 ("NFSD: add listener-{set,get} netlink command") Cc: stable@vger.kernel.org Assisted-by: LLM Link: https://syzkaller.appspot.com/bug?extid=c7eae0eb80858a2dba0f Suggested-by: Olga Kornievskaia Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260901-nfsd-nl-hang-v5-10-a540d86668b0@kernel.org Signed-off-by: Chuck Lever diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 779fd244c771..967c21ff7199 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -2092,7 +2092,10 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) const struct nlattr *bad_attr = NULL; struct svc_xprt *xprt, *tmp; const char *bad_xprt = NULL; + unsigned int rpcb_failures; const struct nlattr *attr; + bool skipped_rpcb = false; + bool bad_rpcb = false; struct svc_serv *serv; LIST_HEAD(permsocks); struct nfsd_net *nn; @@ -2182,13 +2185,16 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) if (delete) svc_xprt_destroy_all(serv, net, false); + rpcb_failures = svc_rpcb_failure_count(serv); + /* walk list of addrs again, open any that still don't exist */ nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_SOCK_ADDR, info->nlhdr, GENL_HDRLEN, rem) { struct nlattr *tb[NFSD_A_SOCK_MAX + 1]; const char *xcl_name; struct sockaddr *sa; - int ret; + bool hit_rpcb; + int flags, ret; /* validated up front in nfsd_nl_validate_listeners() */ if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr, @@ -2207,12 +2213,27 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) continue; } - ret = svc_xprt_create_from_sa(serv, xcl_name, net, sa, 0, + flags = skipped_rpcb ? SVC_SOCK_ANONYMOUS : 0; + ret = svc_xprt_create_from_sa(serv, xcl_name, net, sa, flags, current_cred()); + + hit_rpcb = false; + if (!skipped_rpcb && + svc_rpcb_failure_count(serv) != rpcb_failures) { + skipped_rpcb = true; + hit_rpcb = true; + if (ret < 0) + ret = svc_xprt_create_from_sa(serv, xcl_name, + net, sa, + SVC_SOCK_ANONYMOUS, + current_cred()); + } + /* always save the latest error */ if (ret < 0) { bad_attr = attr; bad_xprt = xcl_name; + bad_rpcb = hit_rpcb; err = ret; } } @@ -2224,8 +2245,21 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) */ if (err) { NL_SET_BAD_ATTR(info->extack, bad_attr); - NL_SET_ERR_MSG_FMT(info->extack, "cannot create %s listener", - bad_xprt); + if (bad_rpcb) + NL_SET_ERR_MSG_FMT(info->extack, + "cannot create %s listener; rpcbind did not answer", + bad_xprt); + else if (skipped_rpcb) + NL_SET_ERR_MSG_FMT(info->extack, + "cannot create %s listener; rpcbind did not answer earlier, so some listeners are not registered", + bad_xprt); + else + NL_SET_ERR_MSG_FMT(info->extack, + "cannot create %s listener", + bad_xprt); + } else if (skipped_rpcb) { + NL_SET_ERR_MSG(info->extack, + "rpcbind did not answer, some listeners are not registered"); } if (!serv->sv_nrthreads && list_empty(&nn->nfsd_serv->sv_permsocks))