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 B6E0E47F2FA; Mon, 31 Aug 2026 13:59:16 +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=1788184757; cv=none; b=twicCu25wUKVfLppq1W8NrjBLht0sRIO4tI6OHHs9cQjHmPxTzzyLkuh34EVTTxQKtlZzzIRmFa6DqSaoOpJpWZg0QmfjeLBeZpfaFl8rp96VQf6JMpkxR3+rhyP+bBy8CLVZzl5mCKVC7ell7oOuPnWUsqDTMZE1Ysr/0jrdvk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788184757; c=relaxed/simple; bh=CC6CR4uQRhUK3aooqfWTq/jSkIJKQaW68q2+t5ABsgY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R83QcNW0i5Xh4N3PV/jYisXAqKWPX8wGyQwGL/et7yvcnSW2gtaKyh8i2T1p8TaoSAbv7CwnkolsGOMVfzXu2zZ6ZpcToYwWh1LQ6jw8arMUhRPpcwXqhqDFouPeJ7ci77Pg6COI7BR+pi9n7XLO2GbgWOnVsO6c6rqIsZ7sGXs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tqcNa49g; 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="tqcNa49g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D3581F000E9; Mon, 31 Aug 2026 13:59:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788184756; bh=vLtZDB0J1xxr1ygrO7eygqw7C2Mm7LuCCB5leXCVh2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=tqcNa49gaZVabRntVEfRoufaD9YJrSzVDbLfwlRibAJh5VgdQLb+YKRJzWxAPz1sY t486YlHj5nKhQFWs/bjI+rmG62cB4L0iVYs8ZZ40TjYXujPzNwz5WMgnrpFNNHknJX Eb9ZorZYljILY8yHOdsR1HNoSohyfqicJVIE5N5s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tetsuo Handa , Oleksij Rempel , Marc Kleine-Budde , Sasha Levin Subject: [PATCH 6.1 20/92] can: j1939: make j1939_sk_bind() fail if device is no longer registered Date: Mon, 31 Aug 2026 15:34:18 +0200 Message-ID: <20260831133400.630348322@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.482388899@linuxfoundation.org> References: <20260831133359.482388899@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tetsuo Handa [ Upstream commit 46cea215dc9444ec32a76b1b6a9cb809e17b64d5 ] There is a theoretical race window in j1939_sk_netdev_event_unregister() where two j1939_sk_bind() calls jump in between read_unlock_bh() and lock_sock(). The assumption jsk->priv == priv can fail if the first j1939_sk_bind() call once made jsk->priv == NULL due to failed j1939_local_ecu_get() call and the second j1939_sk_bind() call again made jsk->priv != NULL due to successful j1939_local_ecu_get() call. Since the socket lock is held by both j1939_sk_netdev_event_unregister() and j1939_sk_bind(), checking ndev->reg_state with the socket lock held can reliably make the second j1939_sk_bind() call fail (and close this race window). Fixes: 7fcbe5b2c6a4 ("can: j1939: implement NETDEV_UNREGISTER notification handler") Signed-off-by: Tetsuo Handa Acked-by: Oleksij Rempel Link: https://patch.msgid.link/5732921e-247e-4957-a364-da74bd7031d7@I-love.SAKURA.ne.jp Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- net/can/j1939/socket.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index 2c15614ea7dde..1b0086198ba36 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -481,6 +481,12 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len) goto out_release_sock; } + if (ndev->reg_state != NETREG_REGISTERED) { + dev_put(ndev); + ret = -ENODEV; + goto out_release_sock; + } + can_ml = can_get_ml_priv(ndev); if (!can_ml) { dev_put(ndev); -- 2.53.0