From patchwork Mon May 24 06:01:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yoshihiro Shimoda X-Patchwork-Id: 12275527 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 C13FAC47083 for ; Mon, 24 May 2021 06:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5FCA610A6 for ; Mon, 24 May 2021 06:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232266AbhEXGDf (ORCPT ); Mon, 24 May 2021 02:03:35 -0400 Received: from relmlor1.renesas.com ([210.160.252.171]:14180 "EHLO relmlie5.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S229824AbhEXGDd (ORCPT ); Mon, 24 May 2021 02:03:33 -0400 X-IronPort-AV: E=Sophos;i="5.82,319,1613401200"; d="scan'208";a="82215983" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie5.idc.renesas.com with ESMTP; 24 May 2021 15:02:05 +0900 Received: from localhost.localdomain (unknown [10.166.14.185]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 0204341BC0C8; Mon, 24 May 2021 15:02:05 +0900 (JST) From: Yoshihiro Shimoda To: balbi@kernel.org Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda Subject: [PATCH] usb: gadget: udc: renesas_usb3: Fix a race in usb3_start_pipen() Date: Mon, 24 May 2021 15:01:55 +0900 Message-Id: <20210524060155.1178724-1-yoshihiro.shimoda.uh@renesas.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The usb3_start_pipen() is called by renesas_usb3_ep_queue() and usb3_request_done_pipen() so that usb3_start_pipen() is possible to cause a race when getting usb3_first_req like below: renesas_usb3_ep_queue() spin_lock_irqsave() list_add_tail() spin_unlock_irqrestore() usb3_start_pipen() usb3_first_req = usb3_get_request() --- [1] --- interrupt --- usb3_irq_dma_int() usb3_request_done_pipen() usb3_get_request() usb3_start_pipen() usb3_first_req = usb3_get_request() ... (the req is possible to be finished in the interrupt) The usb3_first_req [1] above may have been finished after the interrupt ended so that this driver caused to start a transfer wrongly. To fix this issue, getting/checking the usb3_first_req are under spin_lock_irqsave() in the same section. Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Signed-off-by: Yoshihiro Shimoda --- drivers/usb/gadget/udc/renesas_usb3.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c index 0c418ce50ba0..f1b35a39d1ba 100644 --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -1488,7 +1488,7 @@ static void usb3_start_pipen(struct renesas_usb3_ep *usb3_ep, struct renesas_usb3_request *usb3_req) { struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep); - struct renesas_usb3_request *usb3_req_first = usb3_get_request(usb3_ep); + struct renesas_usb3_request *usb3_req_first; unsigned long flags; int ret = -EAGAIN; u32 enable_bits = 0; @@ -1496,7 +1496,8 @@ static void usb3_start_pipen(struct renesas_usb3_ep *usb3_ep, spin_lock_irqsave(&usb3->lock, flags); if (usb3_ep->halt || usb3_ep->started) goto out; - if (usb3_req != usb3_req_first) + usb3_req_first = __usb3_get_request(usb3_ep); + if (!usb3_req_first || usb3_req != usb3_req_first) goto out; if (usb3_pn_change(usb3, usb3_ep->num) < 0)