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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id om12sm8581896pjb.48.2022.01.24.09.22.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 09:22:43 -0800 (PST) From: Kees Cook To: Saeed Mahameed Cc: Kees Cook , Leon Romanovsky , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH RESEND] net/mlx5e: Use struct_group() for memcpy() region Date: Mon, 24 Jan 2022 09:22:41 -0800 Message-Id: <20220124172242.2410996-1-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2499; h=from:subject; bh=1Hy/h6xR6CfzT4qu6mjl1eEfD5rBqmasVCiGJ8yfoaE=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBh7uBhn8A0lQDkjRJO9V5Sl0KNR5PpwAX0g9yKG64U XkTagiOJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYe7gYQAKCRCJcvTf3G3AJrh+D/ 9XD/78mqJDQUOAqNi51dHFcJMTBtQW/5SOOscaza/hl+yTU06iM1xjcDFcsLZb7jaJ4KYcV/EZAnXv l73wUOrNTN38IgVBXoE6OMtjQHaJwjcbzEhxfcnx3ncVKWRelfg1Wcz3UCHgAp621U13ng7iIXtQFg JKnUuwTjUH8vLpNlDdzLwHJqxN7wWA/+r3YU5GGTsWbTGlUZSs4+TPUzhcF48K1Wx5gsWUUBD9lFg5 5oWex5SYi2l7himxmjllot0E3lyw9ot26ak3oWLfRQqqOUet5u4UhWbA1ZBkD6gys1OziqKY2YDzdA L/GNU45qVkr8K5864876AiJ2cFYIFEMng2G2M8xkgH2Pcj0aECmYo+BXt/WC4R5aNKGUbre0I77CKl uCiIH3lTD5mLBNIxe58Lr9ekNwdedX+uNPiZo96/OH0SKqmfp30VohtJJFlB3gauX/slbX9ONDffMR jtuYoEIwR5ODB0gsr3Rku7j/b0nYxJs80sAziKrtJTrlb9tk7RSlanVomFiTGvHxQoI8E8uiRogOG7 7u6sCJqdnF9kLjGpEkjPyi47V741Xkyly/jqjpTJjHzxQHSFinFisqz41YE2HEoINtxxy8kF6n2Rpy +uF1HuWJz6ebx3q5MGvBrhW3cnyzxgaMa1O85G0cJqOg8sujaw7WJe0sV8wQ== 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 bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields. Use struct_group() in struct vlan_ethhdr around members h_dest and h_source, 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 h_dest. "pahole" shows no size nor member offset changes to struct vlan_ethhdr. "objdump -d" shows no object code changes. Cc: Saeed Mahameed Cc: Leon Romanovsky Cc: "David S. Miller" Cc: Jakub Kicinski Cc: netdev@vger.kernel.org Cc: linux-rdma@vger.kernel.org Signed-off-by: Kees Cook --- Since this results in no binary differences, I will carry this in my tree unless someone else wants to pick it up. It's one of the last remaining clean-ups needed for the next step in memcpy() hardening. --- drivers/net/ethernet/mellanox/mlx5/core/en_tx.c | 2 +- include/linux/if_vlan.h | 6 ++++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c index 7fd33b356cc8..ee7ecb88adc1 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c @@ -208,7 +208,7 @@ static inline void mlx5e_insert_vlan(void *start, struct sk_buff *skb, u16 ihs) int cpy1_sz = 2 * ETH_ALEN; int cpy2_sz = ihs - cpy1_sz; - memcpy(vhdr, skb->data, cpy1_sz); + memcpy(&vhdr->addrs, skb->data, cpy1_sz); vhdr->h_vlan_proto = skb->vlan_proto; vhdr->h_vlan_TCI = cpu_to_be16(skb_vlan_tag_get(skb)); memcpy(&vhdr->h_vlan_encapsulated_proto, skb->data + cpy1_sz, cpy2_sz); diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 8420fe504927..2be4dd7e90a9 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -46,8 +46,10 @@ struct vlan_hdr { * @h_vlan_encapsulated_proto: packet type ID or len */ struct vlan_ethhdr { - unsigned char h_dest[ETH_ALEN]; - unsigned char h_source[ETH_ALEN]; + struct_group(addrs, + unsigned char h_dest[ETH_ALEN]; + unsigned char h_source[ETH_ALEN]; + ); __be16 h_vlan_proto; __be16 h_vlan_TCI; __be16 h_vlan_encapsulated_proto;