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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 DA5E4C433ED for ; Mon, 17 May 2021 14:36:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE19A61CB0 for ; Mon, 17 May 2021 14:36:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239288AbhEQOh6 (ORCPT ); Mon, 17 May 2021 10:37:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:43850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240308AbhEQOdw (ORCPT ); Mon, 17 May 2021 10:33:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 851786191F; Mon, 17 May 2021 14:16:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621260990; bh=YJbURjksO0jdbLJvRyfqdFJ0W2nk8ljx8q+OLPu88rU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=toGe3JIOIYbTCHyhj9PH1yDXJ4aLByCcE54Q/Ih5kbM3jYzH1OxM5hY20W89ULmsM RDcfc7v82znjTFS9qI+aajI4DKK65rE3H/WZxr445pMDNzmYOjaWIrsGOQPs44mkvG /yX3ZLVmvrv8iz9GJajtEmdM8RCbLiH41Au9V4FM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Chen , Jack Pham , Sasha Levin Subject: [PATCH 5.12 285/363] usb: dwc3: gadget: Free gadget structure only after freeing endpoints Date: Mon, 17 May 2021 16:02:31 +0200 Message-Id: <20210517140312.241588347@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210517140302.508966430@linuxfoundation.org> References: <20210517140302.508966430@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jack Pham [ Upstream commit bb9c74a5bd1462499fe5ccb1e3c5ac40dcfa9139 ] As part of commit e81a7018d93a ("usb: dwc3: allocate gadget structure dynamically") the dwc3_gadget_release() was added which will free the dwc->gadget structure upon the device's removal when usb_del_gadget_udc() is called in dwc3_gadget_exit(). However, simply freeing the gadget results a dangling pointer situation: the endpoints created in dwc3_gadget_init_endpoints() have their dep->endpoint.ep_list members chained off the list_head anchored at dwc->gadget->ep_list. Thus when dwc->gadget is freed, the first dwc3_ep in the list now has a dangling prev pointer and likewise for the next pointer of the dwc3_ep at the tail of the list. The dwc3_gadget_free_endpoints() that follows will result in a use-after-free when it calls list_del(). This was caught by enabling KASAN and performing a driver unbind. The recent commit 568262bf5492 ("usb: dwc3: core: Add shutdown callback for dwc3") also exposes this as a panic during shutdown. There are a few possibilities to fix this. One could be to perform a list_del() of the gadget->ep_list itself which removes it from the rest of the dwc3_ep chain. Another approach is what this patch does, by splitting up the usb_del_gadget_udc() call into its separate "del" and "put" components. This allows dwc3_gadget_free_endpoints() to be called before the gadget is finally freed with usb_put_gadget(). Fixes: e81a7018d93a ("usb: dwc3: allocate gadget structure dynamically") Reviewed-by: Peter Chen Signed-off-by: Jack Pham Link: https://lore.kernel.org/r/20210501093558.7375-1-jackp@codeaurora.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/dwc3/gadget.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index f85eda6bc988..5fd27160c336 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4024,8 +4024,9 @@ int dwc3_gadget_init(struct dwc3 *dwc) void dwc3_gadget_exit(struct dwc3 *dwc) { - usb_del_gadget_udc(dwc->gadget); + usb_del_gadget(dwc->gadget); dwc3_gadget_free_endpoints(dwc); + usb_put_gadget(dwc->gadget); dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce, dwc->bounce_addr); kfree(dwc->setup_buf); -- 2.30.2