Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933844AbaLKMw6 (ORCPT ); Thu, 11 Dec 2014 07:52:58 -0500 Received: from lekensteyn.nl ([178.21.112.251]:45678 "EHLO lekensteyn.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932882AbaLKMve (ORCPT ); Thu, 11 Dec 2014 07:51:34 -0500 From: Peter Wu To: Benjamin Tissoires , Jiri Kosina , Nestor Lopez Casado , Andrew de los Reyes Cc: Peter Hutterer , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] HID: logitech-hidpp: disable io in probe error path Date: Thu, 11 Dec 2014 13:51:20 +0100 Message-Id: <1418302280-14794-5-git-send-email-peter@lekensteyn.nl> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1418302280-14794-1-git-send-email-peter@lekensteyn.nl> References: <1418302280-14794-1-git-send-email-peter@lekensteyn.nl> X-Spam-Score: -0.0 (/) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Balance a hid_device_io_start() call with hid_device_io_stop() in the error path. This avoids processing of HID reports when the probe fails which possibly leads to invalid memory access in hid_device_probe() as report_enum->report_id_hash might already be freed via hid_close_report(). hid_set_drvdata() is called before wtp_allocate, be consistent and clear drvdata too on the error path of wtp_allocate. Signed-off-by: Peter Wu --- Hi Andrew, There are few users of hid_device_io_start/stop, this is the first one to get start/stop out of sync. Should the comment of hid_device_io_start() be updated to ensure that hid_device_io_stop() gets called before probe() returns? Or should the hid-core be changed to handle this out-of-sync issue: if (ret) { if (hdev->io_started)) down(&hdev->driver_input_lock); hid_close_report(hdev); hdev->driver = NULL; } Is my observation correct or not that HID reports can arrive during hid_close_report() when io_started == true? Kind regards, Peter --- drivers/hid/hid-logitech-hidpp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 4292cc3..2f420c0 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -1121,7 +1121,7 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP) { ret = wtp_allocate(hdev, id); if (ret) - return ret; + goto wtp_allocate_fail; } INIT_WORK(&hidpp->work, delayed_work_cb); @@ -1141,6 +1141,7 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) if (id->group != HID_GROUP_LOGITECH_DJ_DEVICE) { if (!connected) { hid_err(hdev, "Device not connected"); + hid_device_io_stop(hdev); goto hid_parse_fail; } @@ -1186,6 +1187,7 @@ hid_hw_start_fail: hid_parse_fail: cancel_work_sync(&hidpp->work); mutex_destroy(&hidpp->send_mutex); +wtp_allocate_fail: hid_set_drvdata(hdev, NULL); return ret; } -- 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/