From ce08c5555cabcd444d8b77fa69a7cb68bb05f611 Mon Sep 17 00:00:00 2001 From: Baul Lee Date: Wed, 29 Jul 2026 23:24:32 +0900 Subject: [PATCH] HID: universal-pidff: stop the device when force-feedback init fails universal_pidff_probe() starts the device with hid_hw_start() and then, if force-feedback initialisation fails, returns the error through a label that only does "return error". The device is left started. The HID core does not unwind on the driver's behalf. __hid_device_probe() releases the devres group, closes the report and clears hdev->driver: if (ret) { devres_release_group(&hdev->dev, hdev->devres_group_id); hid_close_report(hdev); hdev->driver = NULL; } The hidraw character device that hid_hw_start() registered through hid_connect() is allocated with kzalloc() and added with cdev_device_add(), so it is not devres-managed and survives that. With hdev->driver NULL, hid_device_remove() skips hid_hw_stop() as well, because it only unwinds while a driver is still attached. The registration therefore outlives the device on both paths. Opening the surviving /dev/hidrawX writes into freed memory. KASAN reports a use-after-free write from hidraw_open() -> hid_hw_open() -> the transport's open callback, which takes a spinlock inside the freed object. A descriptor that carries a PID usage page and no input reports is enough: hidraw claims the device so hid_hw_start() succeeds, while hid->inputs stays empty so force-feedback init fails. The other failure returns in hid_pidff_init_with_quirks() - no output reports, an allocation failure, pidff_init_fields(), pidff_check_autocenter(), an unusable effect count, input_ff_create() - all reach the same label. Stop the device on that path. hid-dr.c and hid-emsff.c, which start the device with the same HID_CONNECT_DEFAULT & ~HID_CONNECT_FF mask, already do this. The two earlier gotos must keep returning without hid_hw_stop(), since neither has a started device, so give the path that fails after the start its own label. Discovered by XBOW, triaged by Baul Lee Fixes: f06bf8d94fff ("HID: Add hid-universal-pidff driver and supported device ids") Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Signed-off-by: Jiri Kosina --- drivers/hid/hid-universal-pidff.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-universal-pidff.c b/drivers/hid/hid-universal-pidff.c index 549dac555d40..60180467a0bf 100644 --- a/drivers/hid/hid-universal-pidff.c +++ b/drivers/hid/hid-universal-pidff.c @@ -104,12 +104,14 @@ static int universal_pidff_probe(struct hid_device *hdev, error = init_function(hdev, id->driver_data); if (error) { hid_warn(hdev, "Error initialising force feedback\n"); - goto err; + goto err_stop; } hid_info(hdev, "Universal pidff driver loaded successfully!"); return 0; +err_stop: + hid_hw_stop(hdev); err: return error; }