[PATCH] rtw88: Fix out-of-bounds write

[Len Baker]

In the rtw_pci_init_rx_ring function the "if (len > TRX_BD_IDX_MASK)"
statement guarantees that len is less than or equal to GENMASK(11, 0) or
in other words that len is less than or equal to 4095. However the
rx_ring->buf has a size of RTK_MAX_RX_DESC_NUM (defined as 512). This
way it is possible an out-of-bounds write in the for statement due to
the i variable can exceed the rx_ring->buff size.

Fix it using the ARRAY_SIZE macro.

Cc: stable@xxxxxxxxxxxxxxx
Addresses-Coverity-ID: 1461515 ("Out-of-bounds write")
Fixes: e3037485c68ec ("rtw88: new Realtek 802.11ac driver")
Signed-off-by: Len Baker <len.baker@xxxxxxx>
---
 drivers/net/wireless/realtek/rtw88/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index e7d17ab8f113..b9d8c049e776 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -280,7 +280,7 @@ static int rtw_pci_init_rx_ring(struct rtw_dev *rtwdev,
 	}
 	rx_ring->r.head = head;

-	for (i = 0; i < len; i++) {
+	for (i = 0; i < ARRAY_SIZE(rx_ring->buf); i++) {
 		skb = dev_alloc_skb(buf_sz);
 		if (!skb) {
 			allocated = i;
--
2.25.1