Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753663AbdHKUyp (ORCPT ); Fri, 11 Aug 2017 16:54:45 -0400 Received: from mail-qt0-f178.google.com ([209.85.216.178]:37875 "EHLO mail-qt0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753256AbdHKUyo (ORCPT ); Fri, 11 Aug 2017 16:54:44 -0400 MIME-Version: 1.0 In-Reply-To: <20170811182907.BBAB488201C7@us152.sjc.aristanetworks.com> References: <20170811182907.BBAB488201C7@us152.sjc.aristanetworks.com> From: Francesco Ruggeri Date: Fri, 11 Aug 2017 13:54:42 -0700 Message-ID: Subject: Re: [uio] panic in name_show() To: linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Francesco Ruggeri Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 629 Lines: 18 On Fri, Aug 11, 2017 at 11:29 AM, Francesco Ruggeri wrote: > I have run into this panic while some devices were being hotunplugged, > and I am able to easily reproduce it with the attached module, which > creates a dummy uio device (in my case /sys/class/uio/uio74). > The panic is the result of a race between uio_unregister_device(), > which sets idev->info to NULL, Never mind. The code that is setting idev->info to NULL is coming from a non-standard driver. Sorry for the noise. Francesco Ruggeri > and name_show() which dereferences it. > Seen in 4.9, 3.18 and 3.4. > > Thanks, > Francesco Ruggeri