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=1793818617; b=HnO1iRxUdaMOI4dR5642+PaZzGT80e6NjekubmfmIDrNqgo6QaDAriE5ukrWj5WU3wNP IDQBG1Xf135/kcJ+st4/0/jdd0LKSzWo9Ih5FDvGXoN98Lrjl6zHceiSnWWOEi09WlK1c EHtwjeJldMrA+W5vXn1hOjVDlHafQhsPviash5aAPCImqmPz8BNBnT+M/jqjcPv9JAeli 9nieGDva0dBkPjQoAmGEmatazUPTNHOTz1GwIb9qbcQwGoRlzbGV7JelxDa+Ig3bsnqzW y/lyqvy7j+5MDIW9gYvZ2Q7TUIzfJ6wdzOb2dwgPo7B8UekS3hT1JZAKRrnqkphHgDg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793818617; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=Pr+YMoimPa/MItoiiuAXgUiHcQzEtX0vg6iz6TK0mFE=; b=NTMfryVa/Xka7R6w0zP+myWn/DIteiqXe1T0NRHcNM0Npj9o/mSCRMh62ahc2R3fYesV Z2ZV5528ycbW8sgwmqcxm6HQoJU0c1Y579ykDvft8UBzn/HrcpPoP0xn3SWt5MFOa12ZI vyqH4oLWgA8acx1mjpVpq8c3vDqrK9wwaeiPzhlNVKTpiyrfVPgTp+7NUA5wWUkbvxVpU gjkEgNjWKakKK7LFhuT2DftSueYKws8Tam3finvyg96jzgrYPS4km/KOJQPgNihQRULbF CSguZ0B0p6ePv2c3eqnq3X8UlEDkeL5gfsBXB6Jb3j1h4Fh+0goyLAi3dwYZCUwcdYw== 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=gbvZQcoz; 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 291E7606A337 for ; Wed, 4 Nov 2026 18:56:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=gbvZQcoz Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DC831F00A2C; Wed, 4 Nov 2026 18:56:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793818616; bh=Pr+YMoimPa/MItoiiuAXgUiHcQzEtX0vg6iz6TK0mFE=; h=Subject:To:Cc:From:Date; b=gbvZQcozD2LmxGuL0rB883W530c7tjA5xjxDnAiP7VvWOdG+MuzFGIfbJ4EIjtHRg lX3VvyMqvOIdQeLR1EVExxrdngpXBNRctIT0EFRJEdcp6+1kH3hTqCut51VYbG7SZ0 lNtx+Kx1OJsxTiSZuVHPEu6rRcUEgQhhBIaHGPTg= Subject: FAILED: patch "[PATCH] NFSD: Complete a cld upcall when copying its reply fails" failed to apply to 5.15-stable tree To: cel@kernel.org Cc: From: Date: Wed, 04 Nov 2026 13:56:46 -0500 Message-ID: <2026110446-unshipped-footing-bcc5@gregkh> 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-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 8cef2b0a01d28647facc57501a3df7ccd8d13ccd # git commit -s git send-email --to '' --in-reply-to '2026110446-unshipped-footing-bcc5@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8cef2b0a01d28647facc57501a3df7ccd8d13ccd Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 1 Sep 2026 16:19:43 -0400 Subject: [PATCH] NFSD: Complete a cld upcall when copying its reply fails cld_pipe_downcall() removes the matching upcall from cn_list before copying the daemon's reply. When that copy_from_user() faults, the downcall returns -EFAULT without completing the upcall, and a retried write cannot reach it because its xid is no longer on the list. __cld_pipe_upcall() waits on cu_done uninterruptibly, so the nfsd thread that sent the upcall is stuck, and nfsd shutdown hangs behind it. The pipe is mode 0600, so only a broken or hostile nfsdcld can trigger the fault. Record the fault in the upcall's pipe message and complete it, so the waiter returns the error to its client tracking operation. Fixes: f3f8014862d8 ("nfsd: add the infrastructure to handle the cld upcall") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260901-alemi-v2-3-e163f94a3a6e@kernel.org Signed-off-by: Chuck Lever diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 8dff351aa832..999694db9981 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -835,8 +835,11 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) if (status == -EINPROGRESS) return __cld_pipe_inprogress_downcall(cmsg, nn); - if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0) + if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0) { + cup->cu_pipe_msg.errno = -EFAULT; + complete(&cup->cu_done); return -EFAULT; + } complete(&cup->cu_done); return mlen;