In order to avoid passing around struct sockaddr that has a size the
compiler cannot reason about (nor track at runtime), convert
netif_set_mac_address() to take struct sockaddr_storage. This is just a
cast conversion, so there is are no binary changes. Following patches
will make actual allocation changes.

Acked-by: Gustavo A. R. Silva <gustavo...@kernel.org>
Signed-off-by: Kees Cook <k...@kernel.org>
---
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Eric Dumazet <eduma...@google.com>
Cc: Jakub Kicinski <k...@kernel.org>
Cc: Paolo Abeni <pab...@redhat.com>
Cc: Simon Horman <ho...@kernel.org>
Cc: Andrew Lunn <andrew+net...@lunn.ch>
Cc: Stanislav Fomichev <s...@fomichev.me>
Cc: Cosmin Ratiu <cra...@nvidia.com>
Cc: Lei Yang <leiy...@redhat.com>
Cc: Kuniyuki Iwashima <kun...@amazon.com>
Cc: Ido Schimmel <ido...@nvidia.com>
Cc: <net...@vger.kernel.org>
---
 include/linux/netdevice.h |  2 +-
 net/core/dev.c            | 10 +++++-----
 net/core/dev_api.c        |  4 ++--
 net/core/rtnetlink.c      |  2 +-
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ea9d335de130..47200a394a02 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4212,7 +4212,7 @@ int netif_set_mtu(struct net_device *dev, int new_mtu);
 int dev_set_mtu(struct net_device *, int);
 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
                              struct netlink_ext_ack *extack);
-int netif_set_mac_address(struct net_device *dev, struct sockaddr *sa,
+int netif_set_mac_address(struct net_device *dev, struct sockaddr_storage *ss,
                          struct netlink_ext_ack *extack);
 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
                        struct netlink_ext_ack *extack);
diff --git a/net/core/dev.c b/net/core/dev.c
index fccf2167b235..f8c8aad7df2e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9655,7 +9655,7 @@ int dev_pre_changeaddr_notify(struct net_device *dev, 
const char *addr,
 }
 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
 
-int netif_set_mac_address(struct net_device *dev, struct sockaddr *sa,
+int netif_set_mac_address(struct net_device *dev, struct sockaddr_storage *ss,
                          struct netlink_ext_ack *extack)
 {
        const struct net_device_ops *ops = dev->netdev_ops;
@@ -9663,15 +9663,15 @@ int netif_set_mac_address(struct net_device *dev, 
struct sockaddr *sa,
 
        if (!ops->ndo_set_mac_address)
                return -EOPNOTSUPP;
-       if (sa->sa_family != dev->type)
+       if (ss->ss_family != dev->type)
                return -EINVAL;
        if (!netif_device_present(dev))
                return -ENODEV;
-       err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
+       err = dev_pre_changeaddr_notify(dev, ss->__data, extack);
        if (err)
                return err;
-       if (memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) {
-               err = ops->ndo_set_mac_address(dev, sa);
+       if (memcmp(dev->dev_addr, ss->__data, dev->addr_len)) {
+               err = ops->ndo_set_mac_address(dev, ss);
                if (err)
                        return err;
        }
diff --git a/net/core/dev_api.c b/net/core/dev_api.c
index f9a160ab596f..b5f293e637d9 100644
--- a/net/core/dev_api.c
+++ b/net/core/dev_api.c
@@ -91,7 +91,7 @@ int dev_set_mac_address_user(struct net_device *dev, struct 
sockaddr *sa,
 
        down_write(&dev_addr_sem);
        netdev_lock_ops(dev);
-       ret = netif_set_mac_address(dev, sa, extack);
+       ret = netif_set_mac_address(dev, (struct sockaddr_storage *)sa, extack);
        netdev_unlock_ops(dev);
        up_write(&dev_addr_sem);
 
@@ -332,7 +332,7 @@ int dev_set_mac_address(struct net_device *dev, struct 
sockaddr *sa,
        int ret;
 
        netdev_lock_ops(dev);
-       ret = netif_set_mac_address(dev, sa, extack);
+       ret = netif_set_mac_address(dev, (struct sockaddr_storage *)sa, extack);
        netdev_unlock_ops(dev);
 
        return ret;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 8a914b37ef6e..9743f1c2ae3c 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3100,7 +3100,7 @@ static int do_setlink(const struct sk_buff *skb, struct 
net_device *dev,
 
                memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
                       dev->addr_len);
-               err = netif_set_mac_address(dev, sa, extack);
+               err = netif_set_mac_address(dev, (struct sockaddr_storage *)sa, 
extack);
                kfree(sa);
                if (err) {
                        up_write(&dev_addr_sem);
-- 
2.34.1


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