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 25AFC3D47C5 for ; Sun, 6 Sep 2026 13:28:36 +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=1788701319; cv=none; b=Gd8cbKENBNsXSOtJgSZYKeDExWj2UvPLDLqJaTwv8PQeIFx9PMg6JeCY8ie2aVLa3+VC+/lC49TQdHG2Hu2+1DODjrDdeGdUkCVePopYO09JW/SsUq99Ir3htw61d/d61kO1tBkIDwSGtKGR6kCY+ucxik+MScqure4EM5NwNOE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788701319; c=relaxed/simple; bh=SWUworE4TanJalgMDSdnIHOb9P9dlJLPfKhDoVZmJ/4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mVpjuHhzRGJUnGk4DG4ozTuWE4Gx5ClJYGya51mQczHmaa81I7n3sxlAnSBpQNfaX8meXcgOuQ0XVrfbBATYNiRuf1wy1aqcoXSMvqmK9J6S/RCRug8c+0BN60+Fp5fXQbeW8z/Gzk2ptxX7eTHGKPmB51GkyD0J0BLpDlWbFLM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JtTKcLXY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JtTKcLXY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08A031F00ACA; Sun, 6 Sep 2026 13:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788701316; bh=joRK9bv2oY/I5N94l1wApt5SUKdAwDnw9zHly65n+RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JtTKcLXYum0U/uxrZGZYnEztV2DqwN7BHjZCadNRNb5K9N/FCBv8O/0YFIYpW59Uu xnf0txSUiravWFhEMV/5DOMF/4LF7eXfjb17xkUGOwVR5HWYcULFli4PgZt2SzMIfl a67V9OOJiW76dYPeMa0SQvTJm7Lj4IjCTDDstt+ll5WQrF6+Q9J5EjrjIZQ+hpGpsP Q3Gdm1TilSq8CZmrhic7LqxywH3eVbfpDJ9KqhhlFDG7C31la9wPue3aLPe5+b6XP4 qCJEL8Eu0+bFaasXoFg3ZlEKj8TUuTfyvC2G0u0lMvMiKUD+K8fWkiSlAO0rGTipCu fOIN4rPMB8B7w== From: Sasha Levin To: stable@vger.kernel.org Cc: Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 5.10.y 4/7] nfsd: handle NFS4ERR_BADSLOT on CB_SEQUENCE better Date: Sun, 6 Sep 2026 09:28:28 -0400 Message-ID: <20260906132831.874344-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260906132831.874344-1-sashal@kernel.org> References: <2026090304-heroism-outclass-581e@gregkh> <20260906132831.874344-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jeff Layton [ Upstream commit 999595a651a87f4285c53710b5f600d6a141f526 ] Currently it just restarts the call, without getting a new slot. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Stable-dep-of: 01c5d5f58a5d ("nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown") Signed-off-by: Sasha Levin --- fs/nfsd/nfs4callback.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 52a2f5017c63d..3512e967bc754 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1204,6 +1204,13 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback rpc_delay(task, 2 * HZ); return false; case -NFS4ERR_BADSLOT: + /* + * BADSLOT means that the client and server are out of sync + * as to the backchannel parameters. Mark the backchannel faulty + * and restart the RPC, but leak the slot so no one uses it. + */ + nfsd4_mark_cb_fault(cb->cb_clp); + cb->cb_held_slot = -1; goto retry_nowait; case -NFS4ERR_SEQ_MISORDERED: if (session->se_cb_seq_nr != 1) { -- 2.53.0