From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35092 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732031AbeJBURQ (ORCPT ); Tue, 2 Oct 2018 16:17:16 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Shishkin Subject: [PATCH 4.14 087/137] intel_th: Fix device removal logic Date: Tue, 2 Oct 2018 06:24:48 -0700 Message-Id: <20181002132504.613268310@linuxfoundation.org> In-Reply-To: <20181002132458.446916963@linuxfoundation.org> References: <20181002132458.446916963@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Shishkin commit 8801922cd94c918e4dc3a108ecaa500c4d40583f upstream. Commit a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices") brings in new subdevice addition/removal logic that's broken for "host mode": the SWITCH device has no children to begin with, which is not handled in the code. This results in a null dereference bug later down the path. This patch fixes the subdevice removal code to handle host mode correctly. Signed-off-by: Alexander Shishkin Fixes: a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices") CC: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/intel_th/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -147,7 +147,8 @@ static int intel_th_remove(struct device th->thdev[i] = NULL; } - th->num_thdevs = lowest; + if (lowest >= 0) + th->num_thdevs = lowest; } if (thdrv->attr_group)