[PATCH 5.10 113/406] wifi: mwifiex: avoid possible NULL skb pointer dereference

Greg Kroah-Hartman
2023-09-17T19:26:18Z

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 5c5beedd6aa7b..780ea467471f6 100644
--- a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
@@ -265,7 +265,15 @@ 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