HID: alps: fix NULL pointer dereference in alps_raw_event()

[PATCH] HID: alps: fix NULL pointer dereference in alps_raw_event()

Posted by Greg Kroah-Hartman 2 months, 1 week ago

Commit ecfa6f34492c ("HID: Add HID_CLAIMED_INPUT guards in raw_event
callbacks missing them") attempted to fix up the HID drivers that had
missed the previous fix that was done in 2ff5baa9b527 ("HID: appleir:
Fix potential NULL dereference at raw event handle"), but the alps
driver was missed.

Fix this up by properly checking in the hid-alps driver that it had been
claimed correctly before attempting to process the raw event.

Fixes: 73196ebe134d ("HID: alps: add support for Alps T4 Touchpad device")
Cc: stable <stable@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <bentiss@kernel.org>
Cc: Masaki Ota <masaki.ota@jp.alps.com>
Cc: linux-input@vger.kernel.org
Assisted-by: gregkh_clanker_t1000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/hid/hid-alps.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-alps.c b/drivers/hid/hid-alps.c
index 21e55f3d0d1b..67179e3fe39b 100644
--- a/drivers/hid/hid-alps.c
+++ b/drivers/hid/hid-alps.c
@@ -437,6 +437,9 @@ static int alps_raw_event(struct hid_device *hdev,
 	int ret = 0;
 	struct alps_dev *hdata = hid_get_drvdata(hdev);
 
+	if (!(hdev->claimed & HID_CLAIMED_INPUT) || !hdata->input)
+		return 0;
+
 	switch (hdev->product) {
 	case HID_PRODUCT_ID_T4_BTNLESS:
 		ret = t4_raw_event(hdata, data, size);
-- 
2.53.0

Re: [PATCH] HID: alps: fix NULL pointer dereference in alps_raw_event()

Posted by Jiri Kosina 2 months ago

On Mon, 6 Apr 2026, Greg Kroah-Hartman wrote:

> Commit ecfa6f34492c ("HID: Add HID_CLAIMED_INPUT guards in raw_event
> callbacks missing them") attempted to fix up the HID drivers that had
> missed the previous fix that was done in 2ff5baa9b527 ("HID: appleir:
> Fix potential NULL dereference at raw event handle"), but the alps
> driver was missed.
> 
> Fix this up by properly checking in the hid-alps driver that it had been
> claimed correctly before attempting to process the raw event.
> 
> Fixes: 73196ebe134d ("HID: alps: add support for Alps T4 Touchpad device")
> Cc: stable <stable@kernel.org>
> Cc: Jiri Kosina <jikos@kernel.org>
> Cc: Benjamin Tissoires <bentiss@kernel.org>
> Cc: Masaki Ota <masaki.ota@jp.alps.com>
> Cc: linux-input@vger.kernel.org
> Assisted-by: gregkh_clanker_t1000
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs