From b6a57912854e7ea36f3b270032661140cc4209cd Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Tue, 24 Mar 2026 14:36:44 +0000 Subject: [PATCH] HID: logitech-dj: Prevent REPORT_ID_DJ_SHORT related user initiated OOB write logi_dj_recv_send_report() assumes that all incoming REPORT_ID_DJ_SHORT reports are 14 Bytes (DJREPORT_SHORT_LENGTH - 1) long. It uses that assumption to load the associated field's 'value' array with 14 Bytes of data. However, if a malicious user only sends say 1 Byte of data, 'report_count' will be 1 and only 1 Byte of memory will be allocated to the 'value' Byte array. When we come to populate 'value[1-13]' we will experience an OOB write. Signed-off-by: Lee Jones Signed-off-by: Jiri Kosina --- drivers/hid/hid-logitech-dj.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c index 93f39d3e4e1b0..838c6de9a921c 100644 --- a/drivers/hid/hid-logitech-dj.c +++ b/drivers/hid/hid-logitech-dj.c @@ -1859,6 +1859,7 @@ static int logi_dj_probe(struct hid_device *hdev, const struct hid_device_id *id) { struct hid_report_enum *input_report_enum; + struct hid_report_enum *output_report_enum; struct hid_report *rep; struct dj_receiver_dev *djrcv_dev; struct usb_interface *intf; @@ -1903,6 +1904,15 @@ static int logi_dj_probe(struct hid_device *hdev, } } + output_report_enum = &hdev->report_enum[HID_OUTPUT_REPORT]; + rep = output_report_enum->report_id_hash[REPORT_ID_DJ_SHORT]; + + if (rep->maxfield < 1 || rep->field[0]->report_count != DJREPORT_SHORT_LENGTH - 1) { + hid_err(hdev, "Expected size of DJ short report is %d, but got %d", + DJREPORT_SHORT_LENGTH - 1, rep->field[0]->report_count); + return -EINVAL; + } + input_report_enum = &hdev->report_enum[HID_INPUT_REPORT]; /* no input reports, bail out */ -- 2.47.3