Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751433AbdFFKko (ORCPT ); Tue, 6 Jun 2017 06:40:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:37868 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751384AbdFFKkn (ORCPT ); Tue, 6 Jun 2017 06:40:43 -0400 Date: Tue, 6 Jun 2017 12:39:40 +0200 From: David Sterba To: "Gustavo A. R. Silva" Cc: Jiri Kosina , Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org Subject: Re: [PATCH] tty: ipwireless: fix potential NULL pointer dereference Message-ID: <20170606103940.GY12135@suse.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, "Gustavo A. R. Silva" , Jiri Kosina , Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org References: <20170605205002.GA4896@embeddedgus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170605205002.GA4896@embeddedgus> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 550 Lines: 12 On Mon, Jun 05, 2017 at 03:50:02PM -0500, Gustavo A. R. Silva wrote: > Add null check before dereferencing pointer ver_packet. > Print error message and exit in case pointer ver_packet > is NULL. And what next? The caller does not expect a failure and continues as if the packet has been set up and sent and waiting for a response. This will likely hang somewhere or just do nothing regarding sending/receiving user packets. Failures of alloc_ctrl_packet are handled elsewhere, even during the setup phase so this could be handled more gracefully.