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=1794585383; b=yL3/bS90Av4FstvEBWvv9/aNStcVNNtUWRHLYSBlEmW2+UMcZGBbLW7jbqilxqDa6gA0 HTs0ujVHaTFTXjT8KriwrJPrTCdyf3kG3QuzHysjv7Sagoh0NNoECUkzc6h8kkhjyEnjy 48zWFi+UUcqlwNOIDg+aVYuuUsyI12HjxvMiTMCdVFsatVshHyvNpTtvwj391tlr+Tkcw lqa0mYfykx/mFAfGVz7+sa6IdRpDkgl1hTyv5yvP1ZfLmrAks3ykbpGH12cV6IavNsmYr 6dvZ6lmAdAv6BGyAvNbBDmPzWtJ77vi+ueitZnJ/OGVY2+O8DEg+15Fn8GWq0mxCvdg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794585383; 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=l2rgG0I3AU6TyuTHegM3as5wgvnk+/D0JHF1MEvfERs=; b=rntHIPAjW6T0vgWbLyEd28jEbjuW66uXkGkQLVIfEFv7vpDrvKqVy/WhOxR0HNvEmI63 MLfYvg/WRGw0ybADnVsoi748VAm9YbdnApI4XUc3f4QwRs4NQ620xX8cXBZwO1TK/EOaB QzKsFQ4FjWIEwuhjPxSncHjOb+ZkFKdeKs932lxwwebPyk5WbjpGbDhHSBTamuryIEend 0T8iEZjN11bStnbJAZXa9IIN9+EIPZ7MZynumMR51Y+ZvMGFrwSfpVX0SpjRIMHMNwPzi z0mjYuwnOfFHBb/hVg/MPLpO4UXxxTX+d2oG7FIMoOVvrFsw/It4gZZFELmIUADxG7g== 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=OirfrNh3; 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 BE96560A2627; Fri, 13 Nov 2026 15:56:23 +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=OirfrNh3 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69E6F1F00931; Fri, 13 Nov 2026 15:56:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794585383; bh=l2rgG0I3AU6TyuTHegM3as5wgvnk+/D0JHF1MEvfERs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OirfrNh3RJLt9lnf3IRwDZQvu4S0Rd5NKbN63jtyV/FUF+uROEKIKb+3x3rx+riDh 1RXVXEk+8gfQh5STML+S0VmdleBT7FlTW4MW7GO7kAoBEy4ZQ5GYEoO5SmJqA+uIOk jqsp3cxe0U1EjVqTAoXvcF7I2ovQJOWjz1ZeLPwQ= 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 7.3 018/507] NFSD: Complete a cld upcall when the daemon closes the pipe Date: Fri, 13 Nov 2026 10:45:22 -0500 Message-ID: <20261113153754.036422892@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153753.358973689@linuxfoundation.org> References: <20261113153753.358973689@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-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 6b0c51b8938b5..0b033688aa0b5 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -867,10 +867,34 @@ 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