Commit e716edafedad for kernel
commit e716edafedad4952fe3a4a273d2e039a84e8681a
Author: Lee Jones <lee@kernel.org>
Date: Fri Feb 27 16:30:25 2026 +0000
HID: multitouch: Check to ensure report responses match the request
It is possible for a malicious (or clumsy) device to respond to a
specific report's feature request using a completely different report
ID. This can cause confusion in the HID core resulting in nasty
side-effects such as OOB writes.
Add a check to ensure that the report ID in the response, matches the
one that was requested. If it doesn't, omit reporting the raw event and
return early.
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index b8a748bbf0fd..e82a3c4e5b44 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -526,12 +526,19 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
dev_warn(&hdev->dev, "failed to fetch feature %d\n",
report->id);
} else {
+ /* The report ID in the request and the response should match */
+ if (report->id != buf[0]) {
+ hid_err(hdev, "Returned feature report did not match the request\n");
+ goto free;
+ }
+
ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
size, 0);
if (ret)
dev_warn(&hdev->dev, "failed to report feature\n");
}
+free:
kfree(buf);
}