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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id j8sm343200pfc.8.2021.11.18.10.41.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Nov 2021 10:41:22 -0800 (PST) From: Kees Cook To: Kalle Valo Cc: Kees Cook , "David S. Miller" , Jakub Kicinski , Lee Jones , YueHaibing , Wan Jiabing , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] libertas_tf: Use struct_group() for memcpy() region Date: Thu, 18 Nov 2021 10:41:21 -0800 Message-Id: <20211118184121.1283821-1-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2474; h=from:subject; bh=aN5SRWSO0jhRLPZQ+xEXk4KxeSHDMCg25qp77Fv8hh8=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBhlp5Qeg0TURmPLYxq0mwE2hFWy/0AYNHuIKbeAQlp DWoEAlmJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYZaeUAAKCRCJcvTf3G3AJuSiD/ 4wcpmRD5px9n6yd6xWv+gt3hCr1H9791Cboykwo0Lpp/SHFjH4FZFXODl+Yk+h1qKLUNAVhyaeHdD5 ADLhR1hGYi57Gv7cSAZI9hjopIS2JhOKy8SseJvoBH9XV+zEvzMxVRyIJHkaPpMjvA8Rw8VHba+0wD qBVapKp9KITa6HKnH/imrMShxTcyssHL8gq7t4yipfOjliNPO4LikA2ppq8Z11+vyhvi2BKm9VNl8m LAnFs3PVt1PVVsGYYMBO5TNmu6kZWu9HeDnikMMc4NOBKNWusiT/fPonzIeYVmgzRAGeHQnsQcQ84h qyfKFYGtvKXCn2YSM/TNcxk0h1b5fG1TaLmNtKtuImNhbZylnnK6tq3kgBrTTIq7MjdwvVDT3/24pO zTYInji5mjFrii4gSkR119Ov/UFizJsDhaOrkbDX+b3kNW9xt8DvboOv7WNaKXUg/jZGuBsfhHsWOg uuZPI6u5uYPndGRgLsAfIxMuPQHyi+1w9L/EKxOOZ6NsEn2LjfzmGTYs/ZdFr07sW/YYyaXIWQTrCk UXpaSTtRRrfX+R5NUiIVO1r+Q6qcTtLAHfNeQToQct7l4M12U+Esi6lwI8XmDpPMmuupWueu9v3q1s PL+z3lUwp41eD44PcKvy0a7/bHVNO04v5GifSaKwueC/Yo6IR64WA/+8I85g== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org In preparation for FORTIFY_SOURCE performing compile-time and run-time field array bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields. Use struct_group() in struct txpd around members tx_dest_addr_high and tx_dest_addr_low so they can be referenced together. This will allow memcpy() and sizeof() to more easily reason about sizes, improve readability, and avoid future warnings about writing beyond the end of tx_dest_addr_high. "pahole" shows no size nor member offset changes to struct txpd. "objdump -d" shows no object code changes. Signed-off-by: Kees Cook --- drivers/net/wireless/marvell/libertas_tf/libertas_tf.h | 10 ++++++---- drivers/net/wireless/marvell/libertas_tf/main.c | 3 ++- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h b/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h index 5d726545d987..b2af2ddb6bc4 100644 --- a/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h +++ b/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h @@ -268,10 +268,12 @@ struct txpd { __le32 tx_packet_location; /* Tx packet length */ __le16 tx_packet_length; - /* First 2 byte of destination MAC address */ - u8 tx_dest_addr_high[2]; - /* Last 4 byte of destination MAC address */ - u8 tx_dest_addr_low[4]; + struct_group(tx_dest_addr, + /* First 2 byte of destination MAC address */ + u8 tx_dest_addr_high[2]; + /* Last 4 byte of destination MAC address */ + u8 tx_dest_addr_low[4]; + ); /* Pkt Priority */ u8 priority; /* Pkt Trasnit Power control */ diff --git a/drivers/net/wireless/marvell/libertas_tf/main.c b/drivers/net/wireless/marvell/libertas_tf/main.c index 71492211904b..02a1e1f547d8 100644 --- a/drivers/net/wireless/marvell/libertas_tf/main.c +++ b/drivers/net/wireless/marvell/libertas_tf/main.c @@ -232,7 +232,8 @@ static void lbtf_tx_work(struct work_struct *work) ieee80211_get_tx_rate(priv->hw, info)->hw_value); /* copy destination address from 802.11 header */ - memcpy(txpd->tx_dest_addr_high, skb->data + sizeof(struct txpd) + 4, + BUILD_BUG_ON(sizeof(txpd->tx_dest_addr) != ETH_ALEN); + memcpy(&txpd->tx_dest_addr, skb->data + sizeof(struct txpd) + 4, ETH_ALEN); txpd->tx_packet_length = cpu_to_le16(len); txpd->tx_packet_location = cpu_to_le32(sizeof(struct txpd));