Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755752AbXKSS1q (ORCPT ); Mon, 19 Nov 2007 13:27:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751424AbXKSSWb (ORCPT ); Mon, 19 Nov 2007 13:22:31 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:49318 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752216AbXKSSW3 (ORCPT ); Mon, 19 Nov 2007 13:22:29 -0500 Date: Mon, 19 Nov 2007 10:19:18 -0800 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jiri Kosina , Larry Finger , Marcin Slusarz Subject: [patch 18/26] USB: usbserial - fix potential deadlock between write() and IRQ Message-ID: <20071119181918.GS15425@kroah.com> References: <20071119181438.617190424@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="usb-usbserial-fix-potential-deadlock-between-write-and-irq.patch" In-Reply-To: <20071119181746.GA15425@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) X-Bad-Reply: References and In-Reply-To but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1696 Lines: 51 2.6.22-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jiri Kosina patch acd2a847e7fee7df11817f67dba75a2802793e5d in mainline. USB: usbserial - fix potential deadlock between write() and IRQ usb_serial_generic_write() doesn't disable interrupts when taking port->lock, and could therefore deadlock with usb_serial_generic_read_bulk_callback() being called from interrupt, taking the same lock. Fix it. Signed-off-by: Jiri Kosina Acked-by: Larry Finger Cc: Marcin Slusarz Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/generic.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -190,14 +190,15 @@ int usb_serial_generic_write(struct usb_ /* only do something if we have a bulk out endpoint */ if (serial->num_bulk_out) { - spin_lock_bh(&port->lock); + unsigned long flags; + spin_lock_irqsave(&port->lock, flags); if (port->write_urb_busy) { - spin_unlock_bh(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); dbg("%s - already writing", __FUNCTION__); return 0; } port->write_urb_busy = 1; - spin_unlock_bh(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); count = (count > port->bulk_out_size) ? port->bulk_out_size : count; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/