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 45A5B26158B for ; Sat, 5 Sep 2026 21:43:37 +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=1788644618; cv=none; b=aAOw691Ys45AH8oAgqEI+XnkZXo2/uuS4jUte1i+tpYtC02uN8C2ttmuRFWBLc1NM0AvjcSmkSh3TBaMls8orU1Y3AmDt5b1Epff/ezysavp5un7Er7wZKXTBKay6TzGTQgEZR5SMOV33bV0GgFgGamJbL5XNE0ZCTyBp+w8hm4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788644618; c=relaxed/simple; bh=lHBTyI5zasfNyjDfvpZ4k1I58mY7hc0rUJEtouz2CKs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m8CvzFdF4NqNUafTIg7t9GloBikozi8Xrfwagyh7QOaCdFsO+VVwIw2osY5Zl8F6plGvLun9EJKSYPQE0QqedxKcf+X/zPfYpYoyhE0hbeWPJ+4jYdAo69g+Eqz34ts+pVdJsow3s7QxT9Gck2rTeOlg9r7ri/EC7R8Jw0CudXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=foI01Jqh; 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="foI01Jqh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94F781F00A3A; Sat, 5 Sep 2026 21:43:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788644617; bh=6jzfW3zrdyJPuBaVgHsQkxB6ZtpaKidGThrr/ibkSSs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=foI01JqhU+9WkdoxPcMqh53B6ygj7hgsmYa6WEWa0CHQi2ZaicETu3/NiBbOH4J5h +IPo3Pn7GRTKj7AcEGQEAjrF0vb1EwBNh8Z2BN0N6kkN3BBQV6TGIFVzwL7GdcZ00P 2RsZzBoLGMGI1bInqZ80UN0w07zdMQaJ7aoVymYnBGZjlQ3Qfmzv6bQGdQXCtYYOND a2OoEdexpRmR+S6n29g5RGVdLgCo31SBfDLORY9BN6Abog949h+tdkg42sBXL21070 cgKT78nVvJWvpEH1JLV72s/hqssYRBWLU8lofMtRGz5iQKg+LExPXTmUp8r29cDgmf SivrqzJ4dBhqQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 6.1.y 4/7] nfsd: handle NFS4ERR_BADSLOT on CB_SEQUENCE better Date: Sat, 5 Sep 2026 17:43:29 -0400 Message-ID: <20260905214332.701369-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260905214332.701369-1-sashal@kernel.org> References: <2026090302-gulf-kilometer-60be@gregkh> <20260905214332.701369-1-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 d0e5f46f0f7cd..c918fd3452f31 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1202,6 +1202,13 @@ 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