[PATCH] HID: bigben: fix slab-out-of-bounds Write in bigben_probe

[Dongliang Mu]

From: Dongliang Mu <mudongliangabcd@xxxxxxxxx>

There is a slab-out-of-bounds Write bug in hid-bigbenff driver.
The problem is the driver assumes the device must have an input but
some malicious devices violate this assumption.

Fix this by checking hid_device's input is non-empty before its usage.

Reported-by: syzkaller <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
---
 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 74ad8bf98bfd..c14d1774101d 100644
--- a/drivers/hid/hid-bigbenff.c
+++ b/drivers/hid/hid-bigbenff.c
@@ -347,6 +347,11 @@ static int bigben_probe(struct hid_device *hid,
 	bigben->report = list_entry(report_list->next,
 		struct hid_report, list);
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+
 	hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
 	set_bit(FF_RUMBLE, hidinput->input->ffbit);
 
-- 
2.25.1