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=1793929994; b=dXMgV87jPXew/3H7IiUEGdnmK5n8sfNpa602hzVYBlWijiM24MWB2QJahTko7hR6kSrN 9X0xv6wmCJWWF/EM+QXDjE4rqvMHxzyDVmcWTPu6KdPuefaJWRpyMkh9updsyrSHJbZXI /a38IvNj9MMHn8ZEaSMCpsB4SC5Sn3uHFPLlF+Qase+H7OiPEhjoV51d8S+It8blG42Cw TJfV2q22OTAMeYCHFVt31xEmT4Ap2h8vNjOrRK4x6R5CUhzmRSGykmRdrYyLcnZBNeksK GCTF0XXtOu5OIgEEfmP/snrvMVWlVKJbBjpqvGCw57Pte19HZXCVwkTZIq7Tz2PGOOw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793929994; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=shGtQ0Bi/n1BIHb+Z1JRRM3KA6pVM8CkVKAQIMnjw7w=; b=uu64TbqfOeVlkR44ELlD6oqZF+QddT+rp/31bhcffLJVUhvHFXEpJQ/nTlAKj2FfVoqw Ms0NqUGkKHxmBpNEnBkGYuelxJItuKjFHFC0p2x83yI2i/7zHZdSqqAE57ZLFetNqmS97 7XyNNdxF7/I2fV8SC/icLcM89F6E61VfihvmaNg9B9LCZ0jsysxKCA1RaeQ3DDrJSBHu7 pIX1poMSbWB1HJ+LS/AINLUsquv1oasx39hHoQLeWEc8Fh/K7YkHYJ4RJpuZsgZEhaq+M IfKlV8BFba2VjCh2ouwUfAayCVGg/GWaGMlsW9zBSAP79uVuPVb5Nwi/X+IGpG47YNA== 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=ANkbyfAW; 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 9E282606A333 for ; Fri, 6 Nov 2026 01:53:14 +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=ANkbyfAW Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB0491F008A5; Fri, 6 Nov 2026 01:53:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793929994; bh=shGtQ0Bi/n1BIHb+Z1JRRM3KA6pVM8CkVKAQIMnjw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ANkbyfAWdYDsuvwEpkF3lrPqIqinqMFQJ5sdeazqMmhjt3uyyBGE13yogDehKIhxc ha2R6FrIqevbmQ2r6CVK1EkMCTiBJpkmLVOwbCPVGGrBjpDvQjB3iGliJDhA1NHIU2 ZrF30tZFrMxQ8W6GSvvFVlD37BdS35Ogj3xfMyEDAgPkwezG96LCsZS8kT7ioQCRKt BmoCJ5e6KBFg1H+0TbaelJEawxBFbLRr+L064cxlSvKKAZmz+R+QPdTeFgcCUReOTK xMAzMkr4Eb3xYrjfgFX7/6uIJuk6581jC6F2WpQnGbmmCmrh7SrFrKgs9ddzrK2yWp SE2QPOLJjohpg== From: Sasha Levin To: stable@vger.kernel.org Cc: Jeff Layton , Olga Kornievskaia , Chuck Lever , Sasha Levin Subject: [PATCH 7.3.y 3/3] NFSD: stop registering with rpcbind after a failure in listener_set Date: Thu, 5 Nov 2026 20:53:10 -0500 Message-ID: <20261106015251.3618109-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261106015251.3618109-1-sashal@kernel.org> References: <2026110423-herself-payroll-200f@gregkh> <20261106015251.3618109-1-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 714c73ddd9dc1..d5effeae4b792 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -2089,7 +2089,10 @@ 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; @@ -2179,13 +2182,16 @@ 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, @@ -2204,12 +2210,27 @@ 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; } } @@ -2221,8 +2242,21 @@ 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