[PATCH 1/7] HID: roccat: isku: reject short button reports

[Jiale Yao <yaojiale02@163.com>]

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, for a
button report, read the complete struct isku_report_button.  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: d41c2a7011df ("HID: roccat: Add support for Isku keyboard")
Cc: stable@vger.kernel.org
Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/hid/hid-roccat-isku.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-roccat-isku.c b/drivers/hid/hid-roccat-isku.c
index 93a49c93ae8c..ef1ec9ccaa82 100644
--- a/drivers/hid/hid-roccat-isku.c
+++ b/drivers/hid/hid-roccat-isku.c
@@ -411,6 +411,9 @@ static int isku_raw_event(struct hid_device *hdev,
 	if (isku == NULL)
 		return 0;
 
+	if (size < sizeof(struct isku_report_button))
+		return 0;
+
 	isku_keep_values_up_to_date(isku, data);
 
 	if (isku->roccat_claimed)
-- 
2.34.1