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=1793932743; b=vTPqZ09eucC0gjZikPKT8V7HcjtDOaLCIiOk4/9wSqxCYvXtGd2wemNYMiqG3Ok+IpmI OEHod1i9LHJwIBr0LzlMojbYlfJhML7lGs+6kOgHQ4uDZmVX89Eq9votttb0cNrMxEcEd MOneppbaDiXpwguIgb0hgy5crYCGTERYW0aoErAIMV8Gx1hqE0vVbm/bW/yyl7a8Ot61e oi65Vrs4qmEgdBKvOBHh3RkexiEOi1/12u2nKrZKOQBsxyftpVObhI91UzK+7HlT3ntQk gbXm1dAJP6PWkgSPQjIIZenYxxl3+J+jecsZ9M2Ip1pOIzzW9YNCiXpN6Lvueqzu/6w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793932743; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=FGOM4LQIcCP/gqZ8sXbH9xbdLSjMxPbuCFPOM4kJ6U8=; b=GuPaYmsO8+pfXljaLSfBK3lY8uxVHFwsOtp1dJt/Ez3M5XZ83U06QUzIrRnAoMXU/fu8 NqPeHJCZX7I1QXfiwxZzhClrRLNbDbd9LNZsbiSkqe1kwof1IL+sxwyI6TvrKL+p7ARyA wnrn9b4obczJdKl56Ts1x81ETcGqepvIgNz658SZvzPFGigfOFH8tJjxTv63XefaQtbbu 1RfUFfynof4SqXUfb/6k2+ADyn6jkB9zAKhiQebdwu6HDsrYr5bPndQMDUBnqJcxw+QCs ulxduVKmV7YewV5Th31p4e7RbZwXWTUrYepiSxje173PwPTjGjmP+YPNQ7qVDUEtEFg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=IqaZt8y6; 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 CDEE0606A33C for ; Fri, 6 Nov 2026 02:39:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=IqaZt8y6 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 066441F008A7; Fri, 6 Nov 2026 02:39:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793932742; bh=FGOM4LQIcCP/gqZ8sXbH9xbdLSjMxPbuCFPOM4kJ6U8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IqaZt8y66ZdajPhuNyzQs/1DezmCAYy8qEKnl5+YP7QvpvOC9EmskkMpPBOggLe0k nWOEo1+sUeRRJwcVmitgC6qHHTI/uKPjF8YoMnlO0Rn7FQAbkzp344UZRpe8bpVmxS 7DspARm5QoVpCUMCWf810wc+b16hUVf68BFS5YDMf3HjteOvSX7IhnXlxJkC8Pb1M5 SMmJxMhqMWwGpk7y2eMojKJw9P6NwEUDO8s/6BMmMxN0NJxwWUVUR9vjoKIG4493R2 aVWGuAvo9P3dVsr/d6DXF4DpWvMH2A/1t4sEogtD2QoYKvsl1jt1eKjfGKqDU7BbiH HmDyzjkm4H/xQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Jeff Layton , Olga Kornievskaia , Chuck Lever , Sasha Levin Subject: [PATCH 6.18.y 3/3] NFSD: stop registering with rpcbind after a failure in listener_set Date: Thu, 5 Nov 2026 21:38:59 -0500 Message-ID: <20261106022847.3723642-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261106022847.3723642-1-sashal@kernel.org> References: <2026110424-scope-designed-5ca1@gregkh> <20261106022847.3723642-1-sashal@kernel.org> 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-Transfer-Encoding: 8bit From: Jeff Layton [ Upstream commit bf0f3a37e6ccb78ae80cc6eb2edde4f033c7574c ] 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 Signed-off-by: Sasha Levin --- fs/nfsd/nfsctl.c | 42 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 38 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 49cd0588deb39..9ffa72c15aed2 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -2029,7 +2029,10 @@ 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; @@ -2119,13 +2122,16 @@ 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, @@ -2144,12 +2150,27 @@ 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; } } @@ -2161,8 +2182,21 @@ 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)) -- 2.53.0