[PATCH 4.19 067/273] wifi: mwifiex: avoid possible NULL skb pointer dereference

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dmitry Antipov <dmantipov@yandex.ru>

[ Upstream commit 35a7a1ce7c7d61664ee54f5239a1f120ab95a87e ]

In 'mwifiex_handle_uap_rx_forward()', always check the value
returned by 'skb_copy()' to avoid potential NULL pointer
dereference in 'mwifiex_uap_queue_bridged_pkt()', and drop
original skb in case of copying failure.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 838e4f449297 ("mwifiex: improve uAP RX handling")
Acked-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230814095041.16416-1-dmantipov@yandex.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/marvell/mwifiex/uap_txrx.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
index c723eb16d0914..987057af00fb3 100644
--- a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
@@ -266,7 +266,15 @@ int mwifiex_handle_uap_rx_forward(struct mwifiex_private *priv,
 
 	if (is_multicast_ether_addr(ra)) {
 		skb_uap = skb_copy(skb, GFP_ATOMIC);
-		mwifiex_uap_queue_bridged_pkt(priv, skb_uap);
+		if (likely(skb_uap)) {
+			mwifiex_uap_queue_bridged_pkt(priv, skb_uap);
+		} else {
+			mwifiex_dbg(adapter, ERROR,
+				    "failed to copy skb for uAP\n");
+			priv->stats.rx_dropped++;
+			dev_kfree_skb_any(skb);
+			return -1;
+		}
 	} else {
 		if (mwifiex_get_sta_entry(priv, ra)) {
 			/* Requeue Intra-BSS packet */
-- 
2.40.1