[PATCH 2/2] HID: check empty report_list in bigben_probe()

[Pietro Borrello]

Add a check for empty report_list in bigben_probe().
The missing check causes a type confusion when issuing a list_entry()
on an empty report_list.
The problem is caused by the assumption that the device must
have valid report_list. While this will be true for all normal HID
devices, a suitably malicious device can violate the assumption.

Fixes: 256a90ed9e46 ("HID: hid-bigbenff: driver for BigBen Interactive PS3OFMINIPAD gamepad")
Signed-off-by: Pietro Borrello <borrello@xxxxxxxxxxxxxxxx>
---
 drivers/hid/hid-bigbenff.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/hid/hid-bigbenff.c b/drivers/hid/hid-bigbenff.c
index e8c5e3ac9fff..e8b16665860d 100644
--- a/drivers/hid/hid-bigbenff.c
+++ b/drivers/hid/hid-bigbenff.c
@@ -344,6 +344,11 @@ static int bigben_probe(struct hid_device *hid,
 	}
 
 	report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+	if (list_empty(report_list)) {
+		hid_err(hid, "no output report found\n");
+		error = -ENODEV;
+		goto error_hw_stop;
+	}
 	bigben->report = list_entry(report_list->next,
 		struct hid_report, list);
 

-- 
2.25.1