[PATCH v2] mwl8k: Avoid memcpy() over-reading of mcs.rx_mask

From: Kees Cook <keescook@chromium.org>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Kees Cook <keescook@chromium.org>,
	Lennert Buytenhek <buytenh@wantstofly.org>,
	Kalle Valo <kvalo@codeaurora.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Romain Perier <romain.perier@gmail.com>,
	Allen Pais <allen.lkml@gmail.com>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	wengjianfeng <wengjianfeng@yulong.com>,
	Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	Lv Yunlong <lyl2019@mail.ustc.edu.cn>,
	linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH v2] mwl8k: Avoid memcpy() over-reading of mcs.rx_mask
Date: Wed, 16 Jun 2021 21:14:31 -0700	[thread overview]
Message-ID: <20210617041431.2168953-1-keescook@chromium.org> (raw)

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally reading across neighboring array fields. Use the
sub-structure address directly.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
v2: fix Subject for actual issue
v1: https://lore.kernel.org/lkml/20210616195242.1231287-1-keescook@chromium.org
---
 drivers/net/wireless/marvell/mwl8k.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c
index 84b32a5f01ee..3bf6571f4149 100644
--- a/drivers/net/wireless/marvell/mwl8k.c
+++ b/drivers/net/wireless/marvell/mwl8k.c
@@ -4552,7 +4552,7 @@ static int mwl8k_cmd_update_stadb_add(struct ieee80211_hw *hw,
 	else
 		rates = sta->supp_rates[NL80211_BAND_5GHZ] << 5;
 	legacy_rate_mask_to_array(p->legacy_rates, rates);
-	memcpy(p->ht_rates, sta->ht_cap.mcs.rx_mask, 16);
+	memcpy(p->ht_rates, &sta->ht_cap.mcs, 16);
 	p->interop = 1;
 	p->amsdu_enabled = 0;
 
@@ -5034,7 +5034,7 @@ mwl8k_bss_info_changed_sta(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			ap_legacy_rates =
 				ap->supp_rates[NL80211_BAND_5GHZ] << 5;
 		}
-		memcpy(ap_mcs_rates, ap->ht_cap.mcs.rx_mask, 16);
+		memcpy(ap_mcs_rates, &ap->ht_cap.mcs, 16);
 
 		rcu_read_unlock();
 
-- 
2.25.1

