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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B190BCCA486 for ; Tue, 7 Jun 2022 19:46:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357475AbiFGTpb (ORCPT ); Tue, 7 Jun 2022 15:45:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347044AbiFGSrf (ORCPT ); Tue, 7 Jun 2022 14:47:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4312B4A3E3; Tue, 7 Jun 2022 11:02:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 604C9618E1; Tue, 7 Jun 2022 18:02:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC02AC36AFE; Tue, 7 Jun 2022 18:02:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654624970; bh=AQJUPapWjuLINSh4e/xYgsJ69ZfH1rTid70rZGLesfg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oS+HyF7J2KDr5nNRPnqY7IPtlhtBcu+gtT1ITlPWaBDqqiWY3T0lMIE4q7BykyU1n nQjLjPNe54wFLRiteAtsWqCGSPHcZ2hJ2s6YbxR1kZCpIlyM19LxvrhmaPVgz1L6XV vCKH3rCc24mPGc5VKtcX1+U44x9+aNjstAVEhj60PYNI9jdcQ5cG9xE8hn360cOy1e J8kr61DV9H4/hybVSUfNUZFaBJ26OThRT/1zQVL7B2kyRScb98I91ke7oCtcszqg6f t8aSE+JZkP1WecqErKKBZxKVq3goK8CwcktbNTEaSTISwHGj6d5xTo9STLv0B4BSqq P+wu9I7vgMv7A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marek Szyprowski , Greg Kroah-Hartman , Sasha Levin , hminas@synopsys.com, linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 10/25] usb: dwc2: gadget: don't reset gadget's driver->bus Date: Tue, 7 Jun 2022 14:02:11 -0400 Message-Id: <20220607180229.482040-10-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220607180229.482040-1-sashal@kernel.org> References: <20220607180229.482040-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marek Szyprowski [ Upstream commit 3120aac6d0ecd9accf56894aeac0e265f74d3d5a ] UDC driver should not touch gadget's driver internals, especially it should not reset driver->bus. This wasn't harmful so far, but since commit fc274c1e9973 ("USB: gadget: Add a new bus for gadgets") gadget subsystem got it's own bus and messing with ->bus triggers the following NULL pointer dereference: dwc2 12480000.hsotg: bound driver g_ether 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: ... CPU: 0 PID: 620 Comm: modprobe Not tainted 5.18.0-rc5-next-20220504 #11862 Hardware name: Samsung Exynos (Flattened Device Tree) PC is at module_add_driver+0x44/0xe8 LR is at sysfs_do_create_link_sd+0x84/0xe0 ... Process modprobe (pid: 620, stack limit = 0x(ptrval)) ... module_add_driver from bus_add_driver+0xf4/0x1e4 bus_add_driver from driver_register+0x78/0x10c driver_register from usb_gadget_register_driver_owner+0x40/0xb4 usb_gadget_register_driver_owner from do_one_initcall+0x44/0x1e0 do_one_initcall from do_init_module+0x44/0x1c8 do_init_module from load_module+0x19b8/0x1b9c load_module from sys_finit_module+0xdc/0xfc sys_finit_module from ret_fast_syscall+0x0/0x54 Exception stack(0xf1771fa8 to 0xf1771ff0) ... dwc2 12480000.hsotg: new device is high-speed ---[ end trace 0000000000000000 ]--- Fix this by removing driver->bus entry reset. Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20220505104618.22729-1-m.szyprowski@samsung.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/dwc2/gadget.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index dddc5d02b552..14f907cf71a3 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -4302,7 +4302,6 @@ static int dwc2_hsotg_udc_start(struct usb_gadget *gadget, WARN_ON(hsotg->driver); - driver->driver.bus = NULL; hsotg->driver = driver; hsotg->gadget.dev.of_node = hsotg->dev->of_node; hsotg->gadget.speed = USB_SPEED_UNKNOWN; -- 2.35.1