From nobody Thu Dec 18 13:01:09 2025 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 248D4C32772 for ; Tue, 23 Aug 2022 09:08:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348058AbiHWJH7 (ORCPT ); Tue, 23 Aug 2022 05:07:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347750AbiHWJGo (ORCPT ); Tue, 23 Aug 2022 05:06:44 -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 0C8C285FFE; Tue, 23 Aug 2022 01:29:57 -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 0AD7F61326; Tue, 23 Aug 2022 08:28:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03452C4314C; Tue, 23 Aug 2022 08:28:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661243313; bh=9vjKezl3dOytaASgrXKh7da9oZaZWQxs9UU973wrK9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WjyeJAcc8zQA4for3QIc9Gwn6514e6AfrPM6yCe55DBpW5ntZO3bBqpHeTku+E0AQ sM7bIY+e4PcDvM/bSP4jQxmsJW3q7zjT8MAH0Et5R52lxf8kHjohb6384yf9/KV4xE nZ+aphSzNY/paoxzdiOY1nxr7VPFDlNSUt5EauDQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxim Kochetkov , Hemant Kumar , Manivannan Sadhasivam , Loic Poulain , "David S. Miller" Subject: [PATCH 5.19 207/365] net: qrtr: start MHI channel after endpoit creation Date: Tue, 23 Aug 2022 10:01:48 +0200 Message-Id: <20220823080126.857789357@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080118.128342613@linuxfoundation.org> References: <20220823080118.128342613@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Maxim Kochetkov commit 68a838b84effb7b57ba7d50b1863fc6ae35a54ce upstream. MHI channel may generates event/interrupt right after enabling. It may leads to 2 race conditions issues. 1) Such event may be dropped by qcom_mhi_qrtr_dl_callback() at check: if (!qdev || mhi_res->transaction_status) return; Because dev_set_drvdata(&mhi_dev->dev, qdev) may be not performed at this moment. In this situation qrtr-ns will be unable to enumerate services in device. Reviewed-by: Hemant Kumar Reviewed-by: Loic Poulain Reviewed-by: Manivannan Sadhasivam --------------------------------------------------------------- 2) Such event may come at the moment after dev_set_drvdata() and before qrtr_endpoint_register(). In this case kernel will panic with accessing wrong pointer at qcom_mhi_qrtr_dl_callback(): rc =3D qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr, mhi_res->bytes_xferd); Because endpoint is not created yet. -------------------------------------------------------------- So move mhi_prepare_for_transfer_autoqueue after endpoint creation to fix it. Fixes: a2e2cc0dbb11 ("net: qrtr: Start MHI channels during init") Signed-off-by: Maxim Kochetkov Reviewed-by: Hemant Kumar Reviewed-by: Manivannan Sadhasivam Reviewed-by: Loic Poulain Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/qrtr/mhi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/net/qrtr/mhi.c +++ b/net/qrtr/mhi.c @@ -78,11 +78,6 @@ static int qcom_mhi_qrtr_probe(struct mh struct qrtr_mhi_dev *qdev; int rc; =20 - /* start channels */ - rc =3D mhi_prepare_for_transfer_autoqueue(mhi_dev); - if (rc) - return rc; - qdev =3D devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL); if (!qdev) return -ENOMEM; @@ -96,6 +91,13 @@ static int qcom_mhi_qrtr_probe(struct mh if (rc) return rc; =20 + /* start channels */ + rc =3D mhi_prepare_for_transfer_autoqueue(mhi_dev); + if (rc) { + qrtr_endpoint_unregister(&qdev->ep); + return rc; + } + dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n"); =20 return 0;