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=1794586003; b=CtVfZVUwpahRYMoTrqIBIVCwZt7BPl6RpF21TXP5qB3kDIIb2YIxF0xErDEyHD7efKuB HGH4UsB5EGYTZyh5f65RB0xxYrjZJFlysfCoAHIkqSfI7uAKRL3kbUhqE+p3usEG3Igou Ff0IR+G9+rc/ypUlir7v4yODTN5834tel99bzpjej8GK55pVgfG9c2/gAI9mugWjm/bBp CD7XISM4Qjw64zsNc7gEo8/h64zbzfKmDpFmOYfyP9SFdngHsN48/8nHrdRdISNBNQ3gw FN3b1l8bDoImulnJQ82yiM5ECIPABUuhQrBfAi6vi24roqhLYCa9ifAEyhqF/UK9r+Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794586003; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=hKOYdZv99LI1AC2GO70+l6VFw7Pm4sXKWec2zeK/EdA=; b=NcIse8YEPl58ef1/57OUEj8pYBTUt2Gcg977ZVwBJe9e0VWXuYIbUSq+UxMad/7r95in KFgvCEnyiEiR5xK9pDybrtHr6chtIIzIZFTlqlXE56Cg72WaFURYHH9Gm1WhgomstsUOD YdUARoU8wXTN1m7uyfCDvfvI7pARbxFSwV/u0NLtQfcli37/DKMiaqCcqdS9bDEmaWrI6 4RsebgpPCmQDLqbdCEPbjh5Vl86YbQSCSrnrVvZSKbK1CpzzQwenFr3yKUG6WXJtESwdq jjtUEdIdJrmAFwzYdXZCpigcmZstmNOXozVEFOg6LFt99LXATxXmMUMk05F8DcqjKLg== 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=FqOARpgr; 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 5F1496076E3A; Fri, 13 Nov 2026 16:06:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=FqOARpgr Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C3B31F000C4; Fri, 13 Nov 2026 16:06:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794586003; bh=hKOYdZv99LI1AC2GO70+l6VFw7Pm4sXKWec2zeK/EdA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FqOARpgrBK9RdkP40hQmksO7pgDT4zvNtruXjkQqgoWmzXTBSLh0dEmpjHijCjGrJ KDA/ZmayOOqtGZQZ/S0n7EgKo54hGT0lFYixiuNiTA/z4wCGQCkMTeIyATuHzmyNKA O7k2TbDW2BCVBpPIzoi3EqErlYr9ZQQ27s0PR0LI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Olga Kornievskaia , Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 6.18 043/686] NFSD: stop registering with rpcbind after a failure in listener_set Date: Fri, 13 Nov 2026 10:42:56 -0500 Message-ID: <20261113153822.424774468@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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