From f1ceaaf93ea32d0f2b95c95f784ee155962c52ad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?G=C3=BCnther=20Noack?= Date: Fri, 9 Jan 2026 13:25:58 +0100 Subject: [PATCH] HID: logitech-hidpp: Check maxfield in hidpp_get_report_length() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 1547d41f9f19d691c2c9ce4c29f746297baef9e9 ] Do not crash when a report has no fields. Fake USB gadgets can send their own HID report descriptors and can define report structures without valid fields. This can be used to crash the kernel over USB. Cc: stable@vger.kernel.org Signed-off-by: Günther Noack Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/hid-logitech-hidpp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index b4cc40278739..492a02ca8059 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -4341,7 +4341,7 @@ static int hidpp_get_report_length(struct hid_device *hdev, int id) re = &(hdev->report_enum[HID_OUTPUT_REPORT]); report = re->report_id_hash[id]; - if (!report) + if (!report || !report->maxfield) return 0; return report->field[0]->report_count + 1;