From patchwork Mon Mar 1 16:12:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 389368 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=ham 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 681D2C433E0 for ; Mon, 1 Mar 2021 19:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39B426024A for ; Mon, 1 Mar 2021 19:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241759AbhCATjN (ORCPT ); Mon, 1 Mar 2021 14:39:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:48646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241952AbhCATaB (ORCPT ); Mon, 1 Mar 2021 14:30:01 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8D7ED6507A; Mon, 1 Mar 2021 17:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614619626; bh=iXSB1mLvwZOSh6THQuyyM06xsZZI9qBHP8A2KsdmkO0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kJMaH9PR5VuKGNtCd174ahMawJh1c2ru+wiEHQCXduLbwwHm4yPfx0DD5yzpSKbe+ G4CscJ7VwXZAho34U0mbzLtEM3F5VEX8vog83zig9uh+JUifvZxUuJxFRWeEyzpteQ cbJA1+T+X+4f3VajUtTS6kS1WJb1GVdkF4QckQFE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tony Lindgren , Paul Cercueil Subject: [PATCH 5.10 492/663] usb: musb: Fix runtime PM race in musb_queue_resume_work Date: Mon, 1 Mar 2021 17:12:20 +0100 Message-Id: <20210301161206.185122466@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161141.760350206@linuxfoundation.org> References: <20210301161141.760350206@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -2240,32 +2240,35 @@ 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);