From patchwork Sat Oct 11 11:46:30 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tilman Schmidt X-Patchwork-Id: 398837 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9F10E140145 for ; Sat, 11 Oct 2014 22:47:24 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752227AbaJKLrE (ORCPT ); Sat, 11 Oct 2014 07:47:04 -0400 Received: from mail.pxnet.com ([89.1.7.7]:36362 "EHLO mail.pxnet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751978AbaJKLrD (ORCPT ); Sat, 11 Oct 2014 07:47:03 -0400 Received: from xenon.ts.pxnet.com (p57A57B2C.dip0.t-ipconnect.de [87.165.123.44]) (user=ts author=<> mech=DIGEST-MD5 bits=0) by mail.pxnet.com (8.13.8/8.13.8) with ESMTP id s9BBkkHj020838 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Sat, 11 Oct 2014 13:46:48 +0200 Received: by xenon.ts.pxnet.com (Postfix, from userid 1000) id B6D7B140087; Sat, 11 Oct 2014 13:46:30 +0200 (CEST) Message-Id: <2606e14cb61bc99f0f574b43ff6d9f585f199286.1413021631.git.tilman@imap.cc> In-Reply-To: References: From: Tilman Schmidt Subject: [PATCH 12/12] isdn/gigaset: fix usb_gigaset write_cmd result race To: netdev@vger.kernel.org Cc: David Miller , Dave Jones , Hansjoerg Lipp , Karsten Keil , isdn4linux@listserv.isdn4linux.de Date: Sat, 11 Oct 2014 13:46:30 +0200 (CEST) X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (mail.pxnet.com [89.1.7.7]); Sat, 11 Oct 2014 13:46:48 +0200 (CEST) X-Scanned-By: MIMEDefang 2.70 on 89.1.7.7 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In usb_gigaset function gigaset_write_cmd(), the length field of the command buffer structure could be cleared by the transmit tasklet before it was used for the function's return value. Fix by copying to a local variable before scheduling the tasklet. Signed-off-by: Tilman Schmidt --- drivers/isdn/gigaset/usb-gigaset.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/isdn/gigaset/usb-gigaset.c b/drivers/isdn/gigaset/usb-gigaset.c index 82e91ba..a8e652d 100644 --- a/drivers/isdn/gigaset/usb-gigaset.c +++ b/drivers/isdn/gigaset/usb-gigaset.c @@ -497,6 +497,7 @@ static int send_cb(struct cardstate *cs, struct cmdbuf_t *cb) static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb) { unsigned long flags; + int len; gigaset_dbg_buffer(cs->mstate != MS_LOCKED ? DEBUG_TRANSCMD : DEBUG_LOCKCMD, @@ -515,10 +516,11 @@ static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb) spin_unlock_irqrestore(&cs->cmdlock, flags); spin_lock_irqsave(&cs->lock, flags); + len = cb->len; if (cs->connected) tasklet_schedule(&cs->write_tasklet); spin_unlock_irqrestore(&cs->lock, flags); - return cb->len; + return len; } static int gigaset_write_room(struct cardstate *cs)