From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261986AbVGSTS0 (ORCPT ); Tue, 19 Jul 2005 15:18:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261993AbVGSTS0 (ORCPT ); Tue, 19 Jul 2005 15:18:26 -0400 Received: from H229.C79.B0.tor.eicat.ca ([72.0.79.229]:26981 "EHLO suse.cz") by vger.kernel.org with ESMTP id S261986AbVGSTRC (ORCPT ); Tue, 19 Jul 2005 15:17:02 -0400 Date: Tue, 19 Jul 2005 09:30:58 -0400 From: Vojtech Pavlik To: Pete Zaitcev Cc: linux-kernel@vger.kernel.org Subject: Re: Fw: Oops in hidinput_hid_event Message-ID: <20050719133058.GA7872@ucw.cz> References: <20050718141637.074c6f70.zaitcev@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050718141637.074c6f70.zaitcev@redhat.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 18, 2005 at 02:16:37PM -0700, Pete Zaitcev wrote: > I think this patch is rather obvious, so maybe I should ask Andrew to > apply it to -mm for now, to get some testing. Would that help to verify > it for acceptance? Your patch is perfectly OK, my NULL check was indeed completely wrong. I need to find out how there can be an input event happening without its associated input structure, though, since the oops actually reveals a deeper problem. So that's why I didn't apply the patch yet. > Begin forwarded message: > > Date: Tue, 28 Jun 2005 15:00:23 -0700 > From: Pete Zaitcev > To: vojtech@suse.cz > Cc: zaitcev@redhat.com, linux-usb-devel@lists.sourceforge.net > Subject: Oops in hidinput_hid_event > > Hi, Vojtech: > > Someone reported a bug in Fedora, which runs a largely unmodified upstream > kernel in this area. Whenever the user hits a key which switches LED, > the system oopses. Here's a trace: > > Unable to handle kernel NULL pointer dereference at virtual address 000000c8 > EFLAGS: 00010006 (2.6.11-1.1369_FC4smp) > EIP is at hidinput_hid_event+0x2d/0x292 > Call Trace: > [] hid_process_event+0x57/0x5f > [] hid_input_field+0x2a2/0x2ac > [] hid_input_report+0x9e/0xb8 > [] hid_ctrl+0x14c/0x151 > [] uhci_destroy_urb_priv+0xb5/0x10a [uhci_hcd] > [] usb_hcd_giveback_urb+0x24/0x67 > [] uhci_finish_urb+0x2d/0x38 [uhci_hcd] > [] uhci_finish_completion+0x44/0x56 [uhci_hcd] > [] uhci_scan_schedule+0xaa/0x13a [uhci_hcd] > [] i8042_interrupt+0x121/0x234 > [] uhci_irq+0x47/0x10d [uhci_hcd] > > Full trace at > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=160709 > > Any ideas? > > By the way, it seems that I see a bug in hidinput_hid_event. > The check for NULL can never work, becaue &hidinput->input > is nonzero at all times. How about this? > > --- linux-2.6.12/drivers/usb/input/hid-input.c 2005-06-21 12:58:47.000000000 -0700 > +++ linux-2.6.12-lem/drivers/usb/input/hid-input.c 2005-06-28 14:57:22.000000000 -0700 > @@ -397,11 +397,12 @@ > > void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value, struct pt_regs *regs) > { > - struct input_dev *input = &field->hidinput->input; > + struct input_dev *input; > int *quirks = &hid->quirks; > > - if (!input) > + if (!field->hidinput) > return; > + input = &field->hidinput->input; > > input_regs(input, regs); > > > -- Pete > -- Vojtech Pavlik SuSE Labs, SuSE CR