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=1794590832; b=D3GebxWDG0TtOCrB2Btz90Sr3CwnKx5kWQEYXVqoHckWaPJoFciUqKUnPSSS1m36OLu0 YIA0/tDpYw8hT+YHqhl3OomMXXzTiEanQQ1duLNorkaAEF8O21nzL7ryTdyH6k1NMLOCy 697zsiPd2lj+wSY0nD5wPaZkNkDiA4Nw2MDuOP/6Dbr2GE2FtVcYtLv4/UpFJVyICPVqk 5og4NIp6TVVdkNTZQ5gBqT9MENakKN9dL2ERIYWwSJ9FU5R+eIy1YNb+hOOjBAv8lcK5V /S15f1N40WIDwm44Ob/kKiHErjQaCpl11DE+6VQtH9nKVZsiTTbJ3D3NMNqIL11eI0g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590832; 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=ys9nQaf81lI82prytNt+P9HRg/rFKjSjsPCc5nKD6Z0=; b=cwnIqji9mqO/J1czUr5iC0U6Vmcp5AUJKSgSEtrJKgEVQqMG2LV0Y6A3OgFwwyW0yRy5 JAPzG8bg5oEG9rpAI2aD3hWqb/fLj/Po9vCAak9LptyM7zvrMbIAUhVYsBsP1AzyeTiwj +OE6e1/Xw3esJdkIB65O4pW8n7i+qmhUIuiZKfXtir1tyj+VwXhcCPCzwvQPwdmBlMnJu JDrq8zNDrI1XZF0I31CgGpNKPu/VMlgJM+pEO8HfIEGjvSBH8WbfNSgpRZ5XdTNxXC0YO YuuQZ2PO9iuUwCqFwuuynTO21lEFTjptfTc6jwyeoLNPje9CjerFCVkb25LE1G8jcuQ== 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="rhdeA/m3"; 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 30F5F606D486; Fri, 13 Nov 2026 17:27:12 +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=rhdeA/m3 Received: by smtp.kernel.org (Postfix) with ESMTPSA id D145B1F000C5; Fri, 13 Nov 2026 17:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590832; bh=ys9nQaf81lI82prytNt+P9HRg/rFKjSjsPCc5nKD6Z0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rhdeA/m3/7D4KU879HBayimORp77FqAPoyNASns+R5TfXYWnTAN1pKwehBgRfODDl t6wxbx98ZQz0XDsbzkcTuXkc6NKW9o4xQUoNHzYVmWmNPeiJGjo9HIcpsaCTGtFV6G 33dFFqkyOIKKMjF4PBJVV1IIdrqkJYZ5Vdy9NrFQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+edbebd898142ee5e24ce@syzkaller.appspotmail.com, Chuck Lever , Sasha Levin Subject: [PATCH 6.12 036/670] NFSD: Complete a cld upcall when the daemon closes the pipe Date: Fri, 13 Nov 2026 10:43:20 -0500 Message-ID: <20261113153812.379020861@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 2a83fcb50f3c25c493cc4389619340fefe9d6ac4 ] Once nfsdcld has read a whole upcall, rpc_pipe_read() unlinks the message from every pipe list, so the purges in rpc_pipe_release() and rpc_close_pipes() no longer reach it. cld_upcall_ops supplies no .release_pipe callback, and cld_pipe_destroy_msg() returns without completing the upcall because a downcall is expected to follow. A daemon that exits between the read and the write therefore strands its waiter: the nfsd thread sleeps in TASK_UNINTERRUPTIBLE in __cld_pipe_upcall() and never returns, hung task warnings follow, and the server cannot be shut down. Add a .release_pipe that completes every upcall the daemon has consumed. cu_inflight distinguishes those from upcalls still queued on the pipe, which the framework purges before it calls this callback; cld_pipe_downcall() removes an upcall it accepts from cn_list under the same lock. Neither can be completed twice. Fail the stranded upcall with -EPIPE rather than the -EAGAIN that makes cld_pipe_upcall() retry. The daemon consumed the request, so whether it acted on it before exiting is unknown. Fixes: f3f8014862d8 ("nfsd: add the infrastructure to handle the cld upcall") Reported-by: syzbot+edbebd898142ee5e24ce@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-nfs/6a99f6f0.2e567484.299ffc.000c.GAE@google.com/ Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260901-alemi-v2-7-e163f94a3a6e@kernel.org Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/nfs4recover.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index b493bb059a8b0..9c7f6d90a1b99 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -948,10 +948,34 @@ cld_pipe_destroy_msg(struct rpc_pipe_msg *msg) complete(&cup->cu_done); } +/* + * An upcall the daemon has consumed is off every pipe list, so the + * purge in rpc_pipe_release() and rpc_close_pipes() cannot reach it. + * Release its waiter here instead; no downcall can arrive now. + */ +static void +cld_release_pipe(struct inode *inode) +{ + struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + struct cld_upcall *cup; + + spin_lock(&cn->cn_lock); + list_for_each_entry(cup, &cn->cn_list, cu_list) { + if (!cup->cu_inflight) + continue; + cup->cu_inflight = false; + cup->cu_pipe_msg.errno = -EPIPE; + complete(&cup->cu_done); + } + spin_unlock(&cn->cn_lock); +} + static const struct rpc_pipe_ops cld_upcall_ops = { .upcall = rpc_pipe_generic_upcall, .downcall = cld_pipe_downcall, .destroy_msg = cld_pipe_destroy_msg, + .release_pipe = cld_release_pipe, }; static int -- 2.53.0