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=-18.8 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, 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 34D91C4361A for ; Mon, 1 Mar 2021 17:59:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C507653B7 for ; Mon, 1 Mar 2021 17:59:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239189AbhCAR6s (ORCPT ); Mon, 1 Mar 2021 12:58:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:36900 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232658AbhCAQc1 (ORCPT ); Mon, 1 Mar 2021 11:32:27 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5573364F37; Mon, 1 Mar 2021 16:24:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614615892; bh=aFLZYQKHD5XXhZkBCdfI9AqNICh8NGX8A3+sn9WXcAY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XZVcrlM4HgH3ZQgCGM65nrfRiVeG/bxMSKA2Vhsww7QsDVhQ8hxuXzuhKSQp3ljXz Cy0fnat89dVQTjGj0LYPfWChpJzYwsO/iT/2+bgF6zXrZwq7KzK64gVXvgtl7SeOV9 W5dPd7JmsfHjV4hWsr4g9X/LQOLUZzSUKf4KmOCo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tony Lindgren , Paul Cercueil Subject: [PATCH 4.9 096/134] usb: musb: Fix runtime PM race in musb_queue_resume_work Date: Mon, 1 Mar 2021 17:13:17 +0100 Message-Id: <20210301161018.296433349@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161013.585393984@linuxfoundation.org> References: <20210301161013.585393984@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: Paul Cercueil commit 0eaa1a3714db34a59ce121de5733c3909c529463 upstream. musb_queue_resume_work() would call the provided callback if the runtime PM status was 'active'. Otherwise, it would enqueue the request if the hardware was still suspended (musb->is_runtime_suspended is true). This causes a race with the runtime PM handlers, as it is possible to be in the case where the runtime PM status is not yet 'active', but the hardware has been awaken (PM resume function has been called). When hitting the race, the resume work was not enqueued, which probably triggered other bugs further down the stack. For instance, a telnet connection on Ingenic SoCs would result in a 50/50 chance of a segmentation fault somewhere in the musb code. Rework the code so that either we call the callback directly if (musb->is_runtime_suspended == 0), or enqueue the query otherwise. Fixes: ea2f35c01d5e ("usb: musb: Fix sleeping function called from invalid context for hdrc glue") Cc: stable@vger.kernel.org # v4.9+ Tested-by: Tony Lindgren Reviewed-by: Tony Lindgren Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20210123142502.16980-1-paul@crapouillou.net Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_core.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -2097,32 +2097,35 @@ int musb_queue_resume_work(struct musb * { struct musb_pending_work *w; unsigned long flags; + bool is_suspended; int error; if (WARN_ON(!callback)) return -EINVAL; - if (pm_runtime_active(musb->controller)) - return callback(musb, data); + spin_lock_irqsave(&musb->list_lock, flags); + is_suspended = musb->is_runtime_suspended; - w = devm_kzalloc(musb->controller, sizeof(*w), GFP_ATOMIC); - if (!w) - return -ENOMEM; + if (is_suspended) { + w = devm_kzalloc(musb->controller, sizeof(*w), GFP_ATOMIC); + if (!w) { + error = -ENOMEM; + goto out_unlock; + } + + w->callback = callback; + w->data = data; - w->callback = callback; - w->data = data; - spin_lock_irqsave(&musb->list_lock, flags); - if (musb->is_runtime_suspended) { list_add_tail(&w->node, &musb->pending_list); error = 0; - } else { - dev_err(musb->controller, "could not add resume work %p\n", - callback); - devm_kfree(musb->controller, w); - error = -EINPROGRESS; } + +out_unlock: spin_unlock_irqrestore(&musb->list_lock, flags); + if (!is_suspended) + error = callback(musb, data); + return error; } EXPORT_SYMBOL_GPL(musb_queue_resume_work);