From a3c57a60ce3e4b4726e9a50c6edab840c86e4fdc Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Fri, 27 Feb 2026 16:30:25 +0000 Subject: [PATCH] HID: multitouch: Check to ensure report responses match the request [ Upstream commit e716edafedad4952fe3a4a273d2e039a84e8681a ] 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 Signed-off-by: Benjamin Tissoires Signed-off-by: Sasha Levin Signed-off-by: Ulrich Hecht --- drivers/hid/hid-multitouch.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index d8968f652961..a8f6ca53a01b 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -438,12 +438,19 @@ 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); }