[PATCH 6.6 071/166] HID: alps: fix NULL pointer dereference in alps_raw_event()

Greg Kroah-Hartman
2026-04-24T13:36:33Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1badfc4319224820d5d890f8eab6aa52e4e83339 upstream.

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>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/hid/hid-alps.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/hid/hid-alps.c
+++ b/drivers/hid/hid-alps.c
@@ -437,6 +437,9 @@ static int alps_raw_event(struct hid_dev
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);