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 9611C4772AA; Mon, 31 Aug 2026 13:54:25 +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=1788184466; cv=none; b=kgwUWj5OYRzYuSz40d3jn700gL7N/7vfab+rqh4g9caSxZ0E/TH15mLX9wZRfeVOo4cz9tF1QoCjEKExzZDw34kJNaVNEpL5he0/ac5Fr80KI5swRNpewqXm1sBiMbt1AHM5IQTMx1HhQccptP68sHXTj4OkZzgCVuhhOo6tyQE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788184466; c=relaxed/simple; bh=Gcmicjc9h+2aLhwlcQGOwY9IEXhXoYzhloc/ke5lvLc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i1aysxIr+X9n1qqKn4YpsLjy9TOA93avR+yTJ0/vBKbO7wQdyiBI7ncL5xVIPo/Utdzz91hnRRrnHiw/Lf7Py0Pu/jAkFCEofpm02dHeD8CMmnKDIRUewqEkluLt4jBNC5bqvmrn7kUI7/vKQW8Oc58kC2XVHcSbvRjwiXKsL0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1acECMHI; 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="1acECMHI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D32C01F000E9; Mon, 31 Aug 2026 13:54:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788184465; bh=lMqTUr3BJ9jzI+hcxnwYFQYSohnsSTb42CRudN75dlM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1acECMHI9cXjGGcwNu0NcqDn1fXVgzaV23u04rjvZKiSOOy0cA7fOOUpayJg2LNat ugaOsyDpCZFHkdknxf6KLpws9VI2M+A64f5caZJu7gmlP/cn69vCkQDNqXW4TflrTF dIsEZIxV8aN/tEuZaiJQoXBX0FNApMZVI1uDVNCM= 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 6.6 18/91] can: j1939: make j1939_sk_bind() fail if device is no longer registered Date: Mon, 31 Aug 2026 15:34:06 +0200 Message-ID: <20260831133400.536487361@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.468089036@linuxfoundation.org> References: <20260831133359.468089036@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 6.6-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 eeff9b84fba81..4841aae2fcaad 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