Return-Path: Received: from mail.kernel.org ([198.145.29.99]:51378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932999AbeEHIRx (ORCPT ); Tue, 8 May 2018 04:17:53 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bin Liu Subject: [PATCH 4.9 29/32] usb: musb: host: fix potential NULL pointer dereference Date: Tue, 8 May 2018 10:11:09 +0200 Message-Id: <20180508074013.359992903@linuxfoundation.org> In-Reply-To: <20180508074008.800421598@linuxfoundation.org> References: <20180508074008.800421598@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bin Liu commit 2b63f1329df2cd814c1f8353fae4853ace6521d1 upstream. musb_start_urb() doesn't check the pass-in parameter if it is NULL. But in musb_bulk_nak_timeout() the parameter passed to musb_start_urb() is returned from first_qh(), which could be NULL. So wrap the musb_start_urb() call here with a if condition check to avoid the potential NULL pointer dereference. Fixes: f283862f3b5c ("usb: musb: NAK timeout scheme on bulk TX endpoint") Cc: stable@vger.kernel.org # v3.7+ Signed-off-by: Bin Liu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_host.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -1023,7 +1023,9 @@ static void musb_bulk_nak_timeout(struct /* set tx_reinit and schedule the next qh */ ep->tx_reinit = 1; } - musb_start_urb(musb, is_in, next_qh); + + if (next_qh) + musb_start_urb(musb, is_in, next_qh); } }