Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965036AbaLKPXm (ORCPT ); Thu, 11 Dec 2014 10:23:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47747 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933278AbaLKPXl (ORCPT ); Thu, 11 Dec 2014 10:23:41 -0500 Date: Thu, 11 Dec 2014 10:23:30 -0500 From: Benjamin Tissoires To: Peter Wu Cc: Jiri Kosina , Nestor Lopez Casado , Peter Hutterer , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] HID: logitech-hidpp: check name retrieval return code Message-ID: <20141211152330.GD29747@mail.corp.redhat.com> References: <1418302280-14794-1-git-send-email-peter@lekensteyn.nl> <1418302280-14794-3-git-send-email-peter@lekensteyn.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1418302280-14794-3-git-send-email-peter@lekensteyn.nl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Dec 11 2014 or thereabouts, Peter Wu wrote: > hidpp_devicenametype_get_device_name() may return a negative value on > protocol errors (for example, when the device is powered off). > Explicitly check this condition to avoid a long-running loop. > > (0 cannot be returned as __name_length - index > 0, but check for it > anyway as it would otherwise result in an infinite loop.) > > Signed-off-by: Peter Wu > --- Reviewed-by: Benjamin Tissoires Cheers, Benjamin > drivers/hid/hid-logitech-hidpp.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c > index 5066df8..4d72c20 100644 > --- a/drivers/hid/hid-logitech-hidpp.c > +++ b/drivers/hid/hid-logitech-hidpp.c > @@ -484,10 +484,16 @@ static char *hidpp_get_device_name(struct hidpp_device *hidpp) > if (!name) > return NULL; > > - while (index < __name_length) > - index += hidpp_devicenametype_get_device_name(hidpp, > + while (index < __name_length) { > + ret = hidpp_devicenametype_get_device_name(hidpp, > feature_index, index, name + index, > __name_length - index); > + if (ret <= 0) { > + kfree(name); > + return NULL; > + } > + index += ret; > + } > > return name; > } > -- > 2.1.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/