From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755973Ab0CQWHT (ORCPT ); Wed, 17 Mar 2010 18:07:19 -0400 Received: from mail-ew0-f221.google.com ([209.85.219.221]:36574 "EHLO mail-ew0-f221.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755905Ab0CQWHP (ORCPT ); Wed, 17 Mar 2010 18:07:15 -0400 X-Greylist: delayed 305 seconds by postgrey-1.27 at vger.kernel.org; Wed, 17 Mar 2010 18:06:09 EDT DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=c/F1+udSZAbWI8NK5KAq/4Io2BFsDAk/A4m59mTdVSj574ZUvii4ca+x4Gfy1T0swl Kdzx50AdxvLtjkWdw7QGeWXPYHbzWN+ZLhQjCKJxIXKq8Id5DvmmfgHfv8LnQQkOH29G OG+c4rNpt0GdvnFHE+/eLncwqcuFZgEOIX5T4= From: Johan Hovold To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 7/9] USB: serial: fix missing locking on fifo in write callback Date: Wed, 17 Mar 2010 23:00:43 +0100 Message-Id: <1268863245-17230-8-git-send-email-jhovold@gmail.com> X-Mailer: git-send-email 1.7.0.2 In-Reply-To: <1268863245-17230-1-git-send-email-jhovold@gmail.com> References: <1268863245-17230-1-git-send-email-jhovold@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On errors the fifo was reset without any locking. This could race with write which do kfifo_put and perhaps also chars_in_buffer and write_room. Every other access to the fifo is protected using the port lock so better add it to the error path as well. Signed-off-by: Johan Hovold --- drivers/usb/serial/generic.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 8d6d790..d3ef69f 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -518,10 +518,13 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb) port->write_urb_busy = 0; spin_unlock_irqrestore(&port->lock, flags); - if (status) + if (status) { + spin_lock_irqsave(&port->lock, flags); kfifo_reset_out(&port->write_fifo); - else + spin_unlock_irqrestore(&port->lock, flags); + } else { usb_serial_generic_write_start(port); + } } if (status) -- 1.7.0.2