Messages in this thread Patch in this message | | | From | Peter Wu <> | Subject | [PATCH 4/4] HID: logitech-hidpp: disable io in probe error path | Date | Thu, 11 Dec 2014 13:51:20 +0100 |
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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 <peter@lekensteyn.nl> --- 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
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