From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4EE449B215 for ; Thu, 3 Sep 2026 13:39:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788442784; cv=none; b=rX65VqxGHAww5oBObYCbZ34242+myc4h8ihi5f75rnBblHcPz/cO2segkT/WRL9f4YK8NbcPHFMMnbwNJYq3i9vMymyliOEzgajYgbcSs3l87tzK4kOyWBdNJ2ZngG7WyJAwxBGDkVpXt3jKaA4kzF/R3KphqxqX27RphJcBPGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788442784; c=relaxed/simple; bh=0ewkpL5/xcGOxMrgUmWEg8HbIRiwYude+seuKg6u9+w=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=ZKRKuBn5cUjdlpx7m32vsfMOyG9ZA8BwmnjNxHUL3UMKl0L0WeAROOL6HLnsFfmpBW1UO90xKJLyG1ly1Xo71UJdLwKE42UaMaMnoftL4TkB7Vf/59yNTc6qGFqs1P1Bsdb+x3B9iNXm4b2V42FiyNDhhs8i8yiYK8nEMBFjdro= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IiX9BXWe; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="IiX9BXWe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DF9971F000E9; Thu, 3 Sep 2026 13:39:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788442771; bh=gyAM2g+jGJcysK1gw0wqAY2c8LHwttyoq2A2UYCMpu0=; h=Subject:To:Cc:From:Date; b=IiX9BXWevLqBqBSsfVzl9XeDvliaOb0TVOjngTOYiOQ373JZzq8/kFVaoWeLA8VqY ss7k96gEXDqrF+4gw07Uq5ap+Wc5p37xzcfcXykydZUDiU1UI6cQhV4pBTHKYPhgGN AjH3PPWFZj8b0OVLbfsMrzUNl7F1VXGKLCYVLM+I= Subject: FAILED: patch "[PATCH] nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing" failed to apply to 6.1-stable tree To: jlayton@kernel.org,chuck.lever@oracle.com,clm@meta.com Cc: From: Date: Thu, 03 Sep 2026 15:13:05 +0200 Message-ID: <2026090305-settle-sarcasm-3f00@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 6.1-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-6.1.y git checkout FETCH_HEAD git cherry-pick -x ca94ba36172046be6a694a7986f6931e47ed4d51 # git commit -s git send-email --to '' --in-reply-to '2026090305-settle-sarcasm-3f00@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ca94ba36172046be6a694a7986f6931e47ed4d51 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Sat, 30 May 2026 09:19:17 -0400 Subject: [PATCH] nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke nfsd4_alloc_layout_stateid reads fp->fi_deleg_file without holding fi_lock when the parent stateid is a delegation. A concurrent delegation revoke via the laundromat can clear fi_deleg_file under fi_lock, causing nfsd_file_get() to return NULL and triggering the BUG_ON. This race is client-reachable: two NFS clients can trigger it by having one hold a delegation while another opens the same file to force a recall. When the first client doesn't respond to the recall, the laundromat revokes it. A concurrent LAYOUTGET from any client using the delegation stateid hits the race window. Fix this by taking fi_lock around the fi_deleg_file read in the SC_TYPE_DELEG path, matching the locking discipline of the find_any_file() arm, and replacing the BUG_ON with a graceful error return that cleans up the partially-initialized layout stateid. Fixes: c5c707f96fc9 ("nfsd: implement pNFS layout recalls") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-7 Reported-by: Chris Mason Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260530-nfsd-fixes-v2-1-f27e8eb4d974@kernel.org Signed-off-by: Chuck Lever diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c index f34320e4c2f4..1de2f6cd1f09 100644 --- a/fs/nfsd/nfs4layouts.c +++ b/fs/nfsd/nfs4layouts.c @@ -247,11 +247,17 @@ nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate, nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops, NFSPROC4_CLNT_CB_LAYOUT); - if (parent->sc_type == SC_TYPE_DELEG) + if (parent->sc_type == SC_TYPE_DELEG) { + spin_lock(&fp->fi_lock); ls->ls_file = nfsd_file_get(fp->fi_deleg_file); - else + spin_unlock(&fp->fi_lock); + } else { ls->ls_file = find_any_file(fp); - BUG_ON(!ls->ls_file); + } + if (!ls->ls_file) { + nfs4_put_stid(stp); + return NULL; + } ls->ls_fenced = false; ls->ls_fence_delay = 0;