From fc4ef9d5724973193bfa5ebed181dba6de3a56db Mon Sep 17 00:00:00 2001
From: Dongliang Mu <mudongliangabcd@gmail.com>
Date: Fri, 6 May 2022 15:24:25 +0800
Subject: [PATCH] HID: bigben: fix slab-out-of-bounds Write in bigben_probe
Git-commit: fc4ef9d5724973193bfa5ebed181dba6de3a56db
Patch-mainline: v5.19-rc1
References: git-fixes

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@googlegroups.com>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/hid/hid-bigbenff.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/hid/hid-bigbenff.c b/drivers/hid/hid-bigbenff.c
index 74ad8bf98bfd..e8c5e3ac9fff 100644
--- a/drivers/hid/hid-bigbenff.c
+++ b/drivers/hid/hid-bigbenff.c
@@ -347,6 +347,12 @@ 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");
+		error = -ENODEV;
+		goto error_hw_stop;
+	}
+
 	hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
 	set_bit(FF_RUMBLE, hidinput->input->ffbit);
 
-- 
2.35.3