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authorKees Cook <keescook@chromium.org>2022-01-24 09:22:41 -0800
committerSaeed Mahameed <saeedm@nvidia.com>2022-02-01 20:59:43 -0800
commit6d5c900eb64107001e91e1f46bddc254dded8a59 (patch)
treed502eb88120cd27bae118eb8873ccb19847faf19
parentnet/mlx5e: Avoid implicit modify hdr for decap drop rule (diff)
downloadlinux-dev-6d5c900eb64107001e91e1f46bddc254dded8a59.tar.xz
linux-dev-6d5c900eb64107001e91e1f46bddc254dded8a59.zip
net/mlx5e: Use struct_group() for memcpy() region
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. Fixes: 34802a42b352 ("net/mlx5e: Do not modify the TX SKB") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
-rw-r--r--drivers/net/ethernet/mellanox/mlx5/core/en_tx.c2
-rw-r--r--include/linux/if_vlan.h6
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;