From mboxrd@z Thu Jan 1 00:00:00 1970 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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 8DBE7CA9EBD for ; Fri, 25 Oct 2019 18:06:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F96B205F4 for ; Fri, 25 Oct 2019 18:06:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731691AbfJYSG5 (ORCPT ); Fri, 25 Oct 2019 14:06:57 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46794 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731438AbfJYSFo (ORCPT ); Fri, 25 Oct 2019 14:05:44 -0400 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iO3xv-0008OQ-R9; Fri, 25 Oct 2019 19:05:35 +0100 Received: from ben by deadeye with local (Exim 4.92.2) (envelope-from ) id 1iO3xv-0001ig-EO; Fri, 25 Oct 2019 19:05:35 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Felipe Balbi" , "Kiruthika Varadarajan" Date: Fri, 25 Oct 2019 19:03:16 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 15/47] usb: gadget: ether: Fix race between gether_disconnect and rx_submit In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.76-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Kiruthika Varadarajan commit d29fcf7078bc8be2b6366cbd4418265b53c94fac upstream. On spin lock release in rx_submit, gether_disconnect get a chance to run, it makes port_usb NULL, rx_submit access NULL port USB, hence null pointer crash. Fixed by releasing the lock in rx_submit after port_usb is used. Fixes: 2b3d942c4878 ("usb ethernet gadget: split out network core") Signed-off-by: Kiruthika Varadarajan Signed-off-by: Felipe Balbi [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings --- drivers/usb/gadget/u_ether.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/u_ether.c +++ b/drivers/usb/gadget/u_ether.c @@ -202,11 +202,12 @@ rx_submit(struct eth_dev *dev, struct us out = dev->port_usb->out_ep; else out = NULL; - spin_unlock_irqrestore(&dev->lock, flags); if (!out) + { + spin_unlock_irqrestore(&dev->lock, flags); return -ENOTCONN; - + } /* Padding up to RX_EXTRA handles minor disagreements with host. * Normally we use the USB "terminate on short read" convention; @@ -227,6 +228,7 @@ rx_submit(struct eth_dev *dev, struct us if (dev->port_usb->is_fixed) size = max_t(size_t, size, dev->port_usb->fixed_out_len); + spin_unlock_irqrestore(&dev->lock, flags); skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags); if (skb == NULL) {