From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965285Ab2I1VGF (ORCPT ); Fri, 28 Sep 2012 17:06:05 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:34589 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423167Ab2I1VFu (ORCPT ); Fri, 28 Sep 2012 17:05:50 -0400 X-Sasl-enc: oO3prqFhrq6yAC23cKLXZUfTGOLtnwweiLZ0TyGX20HR 1348866349 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Douglas Bagnall , Mauro Carvalho Chehab , Herton Ronaldo Krzesinski Subject: [ 114/127] media: Avoid sysfs oops when an rc_devs raw device is absent Date: Fri, 28 Sep 2012 13:34:47 -0700 Message-Id: <20120928203059.251984627@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.1.428.g652398a In-Reply-To: <20120928203045.835238916@linuxfoundation.org> References: <20120928203045.835238916@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Douglas Bagnall commit 720bb6436ff30fccad05cf5bdf961ea5b1f5686d upstream. For some reason, when the lirc daemon learns that a usb remote control has been unplugged, it wants to read the sysfs attributes of the disappearing device. This is useful for uncovering transient inconsistencies, but less so for keeping the system running when such inconsistencies exist. Under some circumstances (like every time I unplug my dvb stick from my laptop), lirc catches an rc_dev whose raw event handler has been removed (presumably by ir_raw_event_unregister), and proceeds to interrogate the raw protocols supported by the NULL pointer. This patch avoids the NULL dereference, and ignores the issue of how this state of affairs came about in the first place. Version 2 incorporates changes recommended by Mauro Carvalho Chehab (-ENODEV instead of -EINVAL, and a signed-off-by). Signed-off-by: Douglas Bagnall Signed-off-by: Mauro Carvalho Chehab Cc: Herton Ronaldo Krzesinski Signed-off-by: Greg Kroah-Hartman --- drivers/media/rc/rc-main.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/media/rc/rc-main.c +++ b/drivers/media/rc/rc-main.c @@ -772,10 +772,11 @@ static ssize_t show_protocols(struct dev if (dev->driver_type == RC_DRIVER_SCANCODE) { enabled = dev->rc_map.rc_type; allowed = dev->allowed_protos; - } else { + } else if (dev->raw) { enabled = dev->raw->enabled_protocols; allowed = ir_raw_get_allowed_protocols(); - } + } else + return -ENODEV; IR_dprintk(1, "allowed - 0x%llx, enabled - 0x%llx\n", (long long)allowed,