[PATCH 4/7] HID: roccat: kovaplus: reject short button reports

[Jiale Yao]

The raw event callback runs before HID core validates and zero-pads the
report.  It passes the buffer to helpers which inspect data[0] and read a
complete struct kovaplus_mouse_report_button for button reports.  A
truncated report can therefore cause an out-of-bounds read.

Require enough data for the button report before calling either helper.
Commit 47669bec44fe ("HID: asus: refactor the two workqueues and init
sequence") added the same kind of raw-event length validation to hid-asus.

Fixes: 0e70f97f257e ("HID: roccat: Add support for Kova[+] mouse")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/hid/hid-roccat-kovaplus.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-roccat-kovaplus.c b/drivers/hid/hid-roccat-kovaplus.c
index 9ec42c218ef9..26832b279313 100644
--- a/drivers/hid/hid-roccat-kovaplus.c
+++ b/drivers/hid/hid-roccat-kovaplus.c
@@ -614,6 +614,9 @@ static int kovaplus_raw_event(struct hid_device *hdev,
 	if (kovaplus == NULL)
 		return 0;
 
+	if (size < sizeof(struct kovaplus_mouse_report_button))
+		return 0;
+
 	kovaplus_keep_values_up_to_date(kovaplus, data);
 
 	if (kovaplus->roccat_claimed)
-- 
2.34.1