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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A3B3EC433E7 for ; Mon, 20 Jul 2020 16:14:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E30B2065E for ; Mon, 20 Jul 2020 16:14:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261695; bh=Np+j03ykyif20VWP1W2T8FI6kv/Xhb/bRgfjC8cnNxM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0NINNcr90kPAZJlPa8/yQlF+1SSeNP8T3iqDFLn1WgYG2iBK/5/oXt01pTBMKAOng DQgi9wSS3pZNFu5RjfeH5a572504MhpHKXPG9H6Am6Rc9iXx7V4Rtfgb0c2HCg/5qF Uf/J7rhrCLwFc6dTDMD5JTDwr3SBIhI81QxfES3g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388332AbgGTQOx (ORCPT ); Mon, 20 Jul 2020 12:14:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:55374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387612AbgGTQOr (ORCPT ); Mon, 20 Jul 2020 12:14:47 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B16C2176B; Mon, 20 Jul 2020 16:14:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261686; bh=Np+j03ykyif20VWP1W2T8FI6kv/Xhb/bRgfjC8cnNxM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HaogEOShVet0U9XJvZytsjpHhTa7jTL/8rypaNdEq6858Cg5Gkwi6s4cer4U/S6vS m6I8SiD5VioyxjkhjSKm/qfpQEQgBoqCKJIz0JKzGD2CqJrN2sYbFNAYEgeMTL7Aay SFjUgv42U3482ks49fIEdsYEVqGYuGvZNPQ69Qr8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Shishkin , Andy Shevchenko , Ammy Yi Subject: [PATCH 5.7 204/244] intel_th: Fix a NULL dereference when hub driver is not loaded Date: Mon, 20 Jul 2020 17:37:55 +0200 Message-Id: <20200720152835.555247227@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152825.863040590@linuxfoundation.org> References: <20200720152825.863040590@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Shishkin commit e78e1fdb282726beaf88aa75943682217e6ded0e upstream. Connecting master to an output port when GTH driver module is not loaded triggers a NULL dereference: > RIP: 0010:intel_th_set_output+0x35/0x70 [intel_th] > Call Trace: > ? sth_stm_link+0x12/0x20 [intel_th_sth] > stm_source_link_store+0x164/0x270 [stm_core] > dev_attr_store+0x17/0x30 > sysfs_kf_write+0x3e/0x50 > kernfs_fop_write+0xda/0x1b0 > __vfs_write+0x1b/0x40 > vfs_write+0xb9/0x1a0 > ksys_write+0x67/0xe0 > __x64_sys_write+0x1a/0x20 > do_syscall_64+0x57/0x1d0 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 Make sure the module in question is loaded and return an error if not. Signed-off-by: Alexander Shishkin Fixes: 39f4034693b7c ("intel_th: Add driver infrastructure for Intel(R) Trace Hub devices") Reviewed-by: Andy Shevchenko Reported-by: Ammy Yi Tested-by: Ammy Yi Cc: stable@vger.kernel.org # v4.4 Link: https://lore.kernel.org/r/20200706161339.55468-5-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/intel_th/core.c | 21 ++++++++++++++++++--- drivers/hwtracing/intel_th/sth.c | 4 +--- 2 files changed, 19 insertions(+), 6 deletions(-) --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -1021,15 +1021,30 @@ int intel_th_set_output(struct intel_th_ { struct intel_th_device *hub = to_intel_th_hub(thdev); struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver); + int ret; /* In host mode, this is up to the external debugger, do nothing. */ if (hub->host_mode) return 0; - if (!hubdrv->set_output) - return -ENOTSUPP; + /* + * hub is instantiated together with the source device that + * calls here, so guaranteed to be present. + */ + hubdrv = to_intel_th_driver(hub->dev.driver); + if (!hubdrv || !try_module_get(hubdrv->driver.owner)) + return -EINVAL; - return hubdrv->set_output(hub, master); + if (!hubdrv->set_output) { + ret = -ENOTSUPP; + goto out; + } + + ret = hubdrv->set_output(hub, master); + +out: + module_put(hubdrv->driver.owner); + return ret; } EXPORT_SYMBOL_GPL(intel_th_set_output); --- a/drivers/hwtracing/intel_th/sth.c +++ b/drivers/hwtracing/intel_th/sth.c @@ -161,9 +161,7 @@ static int sth_stm_link(struct stm_data { struct sth_device *sth = container_of(stm_data, struct sth_device, stm); - intel_th_set_output(to_intel_th_device(sth->dev), master); - - return 0; + return intel_th_set_output(to_intel_th_device(sth->dev), master); } static int intel_th_sw_init(struct sth_device *sth)