From patchwork Mon Dec 28 12:50:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 353200 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=unavailable 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 3F53EC43333 for ; Mon, 28 Dec 2020 15:55:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FF5022573 for ; Mon, 28 Dec 2020 15:55:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390565AbgL1Pzk (ORCPT ); Mon, 28 Dec 2020 10:55:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:36124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389436AbgL1Nfr (ORCPT ); Mon, 28 Dec 2020 08:35:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 63F4A20867; Mon, 28 Dec 2020 13:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609162507; bh=gUQzAdPCX55oMJ9NUDZLCAt00yC3cJNBAcYgtNs8HK8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sWXWuvgJr967Za+69Xh2uMC2RAkv4HQanJmnxNJiRvaRRfyLlfAZrgh6lBG9R6BB4 ZvXP4nSBfSOxH2dlpx43X3ZjYaLITauUIJtYaAlv0la8jh5kKYYUWcTiMt4J7tPx5x /e0zVY0B3IIsANtuinysdAh+dNOwvUc7CJYvtVHc= 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 4.19 292/346] USB: serial: keyspan_pda: fix write deadlock Date: Mon, 28 Dec 2020 13:50:11 +0100 Message-Id: <20201228124933.893621116@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -443,6 +443,7 @@ 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 @@ -462,13 +463,13 @@ 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