From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1268C4332E for ; Mon, 28 Dec 2020 13:19:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA9D7207C9 for ; Mon, 28 Dec 2020 13:19:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732924AbgL1NTA (ORCPT ); Mon, 28 Dec 2020 08:19:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:47174 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732869AbgL1NS4 (ORCPT ); Mon, 28 Dec 2020 08:18:56 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id F3D65206ED; Mon, 28 Dec 2020 13:18:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609161520; bh=r9xCeAMs5iAVd1Tko00oM32AUvZdGbhJW/nO/a7uMbc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nMBJh1dhbMm5ld/YIXjdBYQYUTRN8Zp3UYQ5Ek3M0cSBb/b+Z+vdiKZ/bGw6f8uGV OrfFX/UpfZ1ZBZkRHWckprJWrLiA1f+nV6p7cORDrDU5RH7r+gSMDMrF5Un9q7tVR+ j1QnL2pbUwFnCx6C7+zF7gDvwaIRP+YRPJSwiVaA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sebastian Andrzej Siewior , Johan Hovold Subject: [PATCH 4.14 201/242] USB: serial: keyspan_pda: fix write deadlock Date: Mon, 28 Dec 2020 13:50:06 +0100 Message-Id: <20201228124914.573434701@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124904.654293249@linuxfoundation.org> References: <20201228124904.654293249@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold commit 7353cad7ee4deaefc16e94727e69285563e219f6 upstream. The write() callback can be called in interrupt context (e.g. when used as a console) so interrupts must be disabled while holding the port lock to prevent a possible deadlock. Fixes: e81ee637e4ae ("usb-serial: possible irq lock inversion (PPP vs. usb/serial)") Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.") Cc: stable # 2.6.19 Acked-by: Sebastian Andrzej Siewior Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/keyspan_pda.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -447,6 +447,7 @@ static int keyspan_pda_write(struct tty_ int request_unthrottle = 0; int rc = 0; struct keyspan_pda_private *priv; + unsigned long flags; priv = usb_get_serial_port_data(port); /* guess how much room is left in the device's ring buffer, and if we @@ -466,13 +467,13 @@ static int keyspan_pda_write(struct tty_ the TX urb is in-flight (wait until it completes) the device is full (wait until it says there is room) */ - spin_lock_bh(&port->lock); + spin_lock_irqsave(&port->lock, flags); if (!test_bit(0, &port->write_urbs_free) || priv->tx_throttled) { - spin_unlock_bh(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); return 0; } clear_bit(0, &port->write_urbs_free); - spin_unlock_bh(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); /* At this point the URB is in our control, nobody else can submit it again (the only sudden transition was the one from EINPROGRESS to