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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEBF9C43217 for ; Mon, 18 Oct 2021 13:40:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B74C661374 for ; Mon, 18 Oct 2021 13:40:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233511AbhJRNm7 (ORCPT ); Mon, 18 Oct 2021 09:42:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:55246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233736AbhJRNk6 (ORCPT ); Mon, 18 Oct 2021 09:40:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 540906138B; Mon, 18 Oct 2021 13:33:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1634564019; bh=Vw6ttr68ZCstAPpVVICipZAA0bc2xWlXeF1vrKCNfus=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZRIPo804LX3OPGtYZ+PTViu53MXsn5QLz1eriQORkeoJAt+9vxBbbeAw29D+1vnYF ja5t37PP/NnESyy98h1EKIb9cVByPS6pjzXcnmygbLsjZ2pKVRG1ZHhJ9WwyrWFbhf gihBs2rhazTU64eSa83k+5+HBWnH0V7jtKGmLQkk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miquel Raynal Subject: [PATCH 5.10 034/103] usb: musb: dsps: Fix the probe error path Date: Mon, 18 Oct 2021 15:24:10 +0200 Message-Id: <20211018132335.864944908@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211018132334.702559133@linuxfoundation.org> References: <20211018132334.702559133@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: stable@vger.kernel.org From: Miquel Raynal commit c2115b2b16421d93d4993f3fe4c520e91d6fe801 upstream. Commit 7c75bde329d7 ("usb: musb: musb_dsps: request_irq() after initializing musb") has inverted the calls to dsps_setup_optional_vbus_irq() and dsps_create_musb_pdev() without updating correctly the error path. dsps_create_musb_pdev() allocates and registers a new platform device which must be unregistered and freed with platform_device_unregister(), and this is missing upon dsps_setup_optional_vbus_irq() error. While on the master branch it seems not to trigger any issue, I observed a kernel crash because of a NULL pointer dereference with a v5.10.70 stable kernel where the patch mentioned above was backported. With this kernel version, -EPROBE_DEFER is returned the first time dsps_setup_optional_vbus_irq() is called which triggers the probe to error out without unregistering the platform device. Unfortunately, on the Beagle Bone Black Wireless, the platform device still living in the system is being used by the USB Ethernet gadget driver, which during the boot phase triggers the crash. My limited knowledge of the musb world prevents me to revert this commit which was sent to silence a robot warning which, as far as I understand, does not make sense. The goal of this patch was to prevent an IRQ to fire before the platform device being registered. I think this cannot ever happen due to the fact that enabling the interrupts is done by the ->enable() callback of the platform musb device, and this platform device must be already registered in order for the core or any other user to use this callback. Hence, I decided to fix the error path, which might prevent future errors on mainline kernels while also fixing older ones. Fixes: 7c75bde329d7 ("usb: musb: musb_dsps: request_irq() after initializing musb") Cc: stable@vger.kernel.org Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/r/20211005221631.1529448-1-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_dsps.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/usb/musb/musb_dsps.c +++ b/drivers/usb/musb/musb_dsps.c @@ -899,11 +899,13 @@ static int dsps_probe(struct platform_de if (usb_get_dr_mode(&pdev->dev) == USB_DR_MODE_PERIPHERAL) { ret = dsps_setup_optional_vbus_irq(pdev, glue); if (ret) - goto err; + goto unregister_pdev; } return 0; +unregister_pdev: + platform_device_unregister(glue->musb); err: pm_runtime_disable(&pdev->dev); iounmap(glue->usbss_base);