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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D1BD2C3A5A1 for ; Thu, 22 Aug 2019 13:40:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A796723401 for ; Thu, 22 Aug 2019 13:40:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="Dl9L/ISJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389192AbfHVNkp (ORCPT ); Thu, 22 Aug 2019 09:40:45 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:47650 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389189AbfHVNko (ORCPT ); Thu, 22 Aug 2019 09:40:44 -0400 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id x7MDeVu5088189; Thu, 22 Aug 2019 08:40:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1566481231; bh=snaiQFyiKmw4m9JXHWRa9VJ1PxzA6iRYaZc9+TjBxdU=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=Dl9L/ISJt/z8EpEiC5FrCtNUgGTZnlLYdWzZp7lFHGkEMWC7TtisKSejTcZz3crES NVyvLmvHH6kX/NS3YweMZCHvGOK808vwn0YKqAc0B81nxg6btppiRCvlXNLTGNBicO XzFwxmiZhgyy46y4ytaYaD4VUNLAolwC8BRzB7cI= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x7MDeVAW009576 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 22 Aug 2019 08:40:31 -0500 Received: from DFLE101.ent.ti.com (10.64.6.22) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Thu, 22 Aug 2019 08:40:31 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE101.ent.ti.com (10.64.6.22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Thu, 22 Aug 2019 08:40:31 -0500 Received: from lta0400828a.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id x7MDeT3P050012; Thu, 22 Aug 2019 08:40:29 -0500 From: Roger Quadros To: , CC: , , , Roger Quadros Subject: [PATCH v2] usb: gadget: udc: core: Fix segfault if udc_bind_to_driver() for pending driver fails Date: Thu, 22 Aug 2019 16:40:28 +0300 Message-ID: <20190822134028.2623-1-rogerq@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190821101201.5377-1-rogerq@ti.com> References: <20190821101201.5377-1-rogerq@ti.com> MIME-Version: 1.0 Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If a gadget driver is in the pending drivers list, a UDC becomes available and udc_bind_to_driver() fails, then it gets deleted from the pending list. i.e. list_del(&driver->pending) in check_pending_gadget_drivers(). Then if that gadget driver is unregistered, usb_gadget_unregister_driver() does a list_del(&driver->pending) again thus causing a page fault as that list entry has been poisoned by the previous list_del(). Fix this by using list_del_init() instead of list_del() in check_pending_gadget_drivers(). Test case: - Make sure no UDC is available - modprobe g_mass_storage file=wrongfile - Load UDC driver so it becomes available lun0: unable to open backing file: wrongfile - modprobe -r g_mass_storage [ 60.900431] Unable to handle kernel paging request at virtual address dead000000000108 [ 60.908346] Mem abort info: [ 60.911145] ESR = 0x96000044 [ 60.914227] Exception class = DABT (current EL), IL = 32 bits [ 60.920162] SET = 0, FnV = 0 [ 60.923217] EA = 0, S1PTW = 0 [ 60.926354] Data abort info: [ 60.929228] ISV = 0, ISS = 0x00000044 [ 60.933058] CM = 0, WnR = 1 [ 60.936011] [dead000000000108] address between user and kernel address ranges [ 60.943136] Internal error: Oops: 96000044 [#1] PREEMPT SMP [ 60.948691] Modules linked in: g_mass_storage(-) usb_f_mass_storage libcomposite xhci_plat_hcd xhci_hcd usbcore ti_am335x_adc kfifo_buf omap_rng cdns3 rng_core udc_core crc32_ce xfrm_user crct10dif_ce snd_so6 [ 60.993995] Process modprobe (pid: 834, stack limit = 0x00000000c2aebc69) [ 61.000765] CPU: 0 PID: 834 Comm: modprobe Not tainted 4.19.59-01963-g065f42a60499 #92 [ 61.008658] Hardware name: Texas Instruments SoC (DT) [ 61.014472] pstate: 60000005 (nZCv daif -PAN -UAO) [ 61.019253] pc : usb_gadget_unregister_driver+0x7c/0x108 [udc_core] [ 61.025503] lr : usb_gadget_unregister_driver+0x30/0x108 [udc_core] [ 61.031750] sp : ffff00001338fda0 [ 61.035049] x29: ffff00001338fda0 x28: ffff800846d40000 [ 61.040346] x27: 0000000000000000 x26: 0000000000000000 [ 61.045642] x25: 0000000056000000 x24: 0000000000000800 [ 61.050938] x23: ffff000008d7b0d0 x22: ffff0000088b07c8 [ 61.056234] x21: ffff000001100000 x20: ffff000002020260 [ 61.061530] x19: ffff0000010ffd28 x18: 0000000000000000 [ 61.066825] x17: 0000000000000000 x16: 0000000000000000 [ 61.072121] x15: 0000000000000000 x14: 0000000000000000 [ 61.077417] x13: ffff000000000000 x12: ffffffffffffffff [ 61.082712] x11: 0000000000000030 x10: 7f7f7f7f7f7f7f7f [ 61.088008] x9 : fefefefefefefeff x8 : 0000000000000000 [ 61.093304] x7 : ffffffffffffffff x6 : 000000000000ffff [ 61.098599] x5 : 8080000000000000 x4 : 0000000000000000 [ 61.103895] x3 : ffff000001100020 x2 : ffff800846d40000 [ 61.109190] x1 : dead000000000100 x0 : dead000000000200 [ 61.114486] Call trace: [ 61.116922] usb_gadget_unregister_driver+0x7c/0x108 [udc_core] [ 61.122828] usb_composite_unregister+0x10/0x18 [libcomposite] [ 61.128643] msg_cleanup+0x18/0xfce0 [g_mass_storage] [ 61.133682] __arm64_sys_delete_module+0x17c/0x1f0 [ 61.138458] el0_svc_common+0x90/0x158 [ 61.142192] el0_svc_handler+0x2c/0x80 [ 61.145926] el0_svc+0x8/0xc [ 61.148794] Code: eb03003f d10be033 54ffff21 a94d0281 (f9000420) [ 61.154869] ---[ end trace afb22e9b637bd9a7 ]--- Segmentation fault Signed-off-by: Roger Quadros --- Changelog: v2 - Retain policy behaviour if pending gadget driver fails to bind. drivers/usb/gadget/udc/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 7cf34beb50df..92af8dc98c3d 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1143,7 +1143,7 @@ static int check_pending_gadget_drivers(struct usb_udc *udc) dev_name(&udc->dev)) == 0) { ret = udc_bind_to_driver(udc, driver); if (ret != -EPROBE_DEFER) - list_del(&driver->pending); + list_del_init(&driver->pending); break; } -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. 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