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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 6A317C43381 for ; Thu, 21 Feb 2019 15:50:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42BE520823 for ; Thu, 21 Feb 2019 15:50:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728584AbfBUPue (ORCPT ); Thu, 21 Feb 2019 10:50:34 -0500 Received: from mga02.intel.com ([134.134.136.20]:50434 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728535AbfBUPua (ORCPT ); Thu, 21 Feb 2019 10:50:30 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 21 Feb 2019 07:50:30 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,395,1544515200"; d="scan'208";a="136108167" Received: from black.fi.intel.com (HELO black.fi.intel.com.) ([10.237.72.28]) by orsmga002.jf.intel.com with ESMTP; 21 Feb 2019 07:50:27 -0800 From: Alexander Shishkin To: Greg Kroah-Hartman Cc: Mathieu Poirier , linux-kernel@vger.kernel.org, Alexander Shishkin , stable@vger.kernel.org, Ammy Yi Subject: [GIT PULL v1 5/7] intel_th: Don't reference unassigned outputs Date: Thu, 21 Feb 2019 17:50:04 +0200 Message-Id: <20190221155006.76832-6-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190221155006.76832-1-alexander.shishkin@linux.intel.com> References: <20190221155006.76832-1-alexander.shishkin@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When an output port driver is removed, also remove references to it from any masters. Failing to do this causes a NULL ptr dereference when configuring another output port: > BUG: unable to handle kernel NULL pointer dereference at 000000000000000d > RIP: 0010:master_attr_store+0x9d/0x160 [intel_th_gth] > Call Trace: > dev_attr_store+0x1b/0x30 > sysfs_kf_write+0x3c/0x50 > kernfs_fop_write+0x125/0x1a0 > __vfs_write+0x3a/0x190 > ? __vfs_write+0x5/0x190 > ? _cond_resched+0x1a/0x50 > ? rcu_all_qs+0x5/0xb0 > ? __vfs_write+0x5/0x190 > vfs_write+0xb8/0x1b0 > ksys_write+0x55/0xc0 > __x64_sys_write+0x1a/0x20 > do_syscall_64+0x5a/0x140 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Alexander Shishkin Fixes: b27a6a3f97b9 ("intel_th: Add Global Trace Hub driver") CC: stable@vger.kernel.org # v4.4+ Reported-by: Ammy Yi --- drivers/hwtracing/intel_th/gth.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwtracing/intel_th/gth.c b/drivers/hwtracing/intel_th/gth.c index 8426b7970c14..cc287cf6eb29 100644 --- a/drivers/hwtracing/intel_th/gth.c +++ b/drivers/hwtracing/intel_th/gth.c @@ -607,6 +607,7 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev, { struct gth_device *gth = dev_get_drvdata(&thdev->dev); int port = othdev->output.port; + int master; if (thdev->host_mode) return; @@ -615,6 +616,9 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev, othdev->output.port = -1; othdev->output.active = false; gth->output[port].output = NULL; + for (master = 0; master < TH_CONFIGURABLE_MASTERS; master++) + if (gth->master[master] == port) + gth->master[master] = -1; spin_unlock(>h->gth_lock); } -- 2.20.1