From patchwork Wed Mar 20 08:59:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felipe Balbi X-Patchwork-Id: 10861075 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4D39915AC for ; Wed, 20 Mar 2019 08:59:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3046B29A1A for ; Wed, 20 Mar 2019 08:59:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 24A7F29A17; Wed, 20 Mar 2019 08:59:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB5022901C for ; Wed, 20 Mar 2019 08:59:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726839AbfCTI7T (ORCPT ); Wed, 20 Mar 2019 04:59:19 -0400 Received: from mga11.intel.com ([192.55.52.93]:24581 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbfCTI7T (ORCPT ); Wed, 20 Mar 2019 04:59:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Mar 2019 01:59:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,248,1549958400"; d="scan'208";a="308742896" Received: from pipin.fi.intel.com (HELO localhost) ([10.237.72.175]) by orsmga005.jf.intel.com with ESMTP; 20 Mar 2019 01:59:16 -0700 From: Felipe Balbi To: Linux USB Cc: Radoslav Gerganov , James Bottomley , stable@vger.kernel.org, Felipe Balbi Subject: [PATCH] USB: gadget: f_hid: fix deadlock in f_hidg_write() Date: Wed, 20 Mar 2019 10:59:14 +0200 Message-Id: <20190320085914.22422-1-felipe.balbi@linux.intel.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Radoslav Gerganov In f_hidg_write() the write_spinlock is acquired before calling usb_ep_queue() which causes a deadlock when dummy_hcd is being used. This is because dummy_queue() callbacks into f_hidg_req_complete() which tries to acquire the same spinlock. This is (part of) the backtrace when the deadlock occurs: 0xffffffffc06b1410 in f_hidg_req_complete 0xffffffffc06a590a in usb_gadget_giveback_request 0xffffffffc06cfff2 in dummy_queue 0xffffffffc06a4b96 in usb_ep_queue 0xffffffffc06b1eb6 in f_hidg_write 0xffffffff8127730b in __vfs_write 0xffffffff812774d1 in vfs_write 0xffffffff81277725 in SYSC_write Fix this by releasing the write_spinlock before calling usb_ep_queue() Reviewed-by: James Bottomley Tested-by: James Bottomley Cc: stable@vger.kernel.org # 4.11+ Fixes: 749494b6bdbb ("usb: gadget: f_hid: fix: Move IN request allocation to set_alt()") Signed-off-by: Radoslav Gerganov Signed-off-by: Felipe Balbi --- drivers/usb/gadget/function/f_hid.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 75b113a5b25c..f3816a5c861e 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -391,20 +391,20 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer, req->complete = f_hidg_req_complete; req->context = hidg; + spin_unlock_irqrestore(&hidg->write_spinlock, flags); + status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC); if (status < 0) { ERROR(hidg->func.config->cdev, "usb_ep_queue error on int endpoint %zd\n", status); - goto release_write_pending_unlocked; + goto release_write_pending; } else { status = count; } - spin_unlock_irqrestore(&hidg->write_spinlock, flags); return status; release_write_pending: spin_lock_irqsave(&hidg->write_spinlock, flags); -release_write_pending_unlocked: hidg->write_pending = 0; spin_unlock_irqrestore(&hidg->write_spinlock, flags);