dev_set_mac_address() accepts a struct sockaddr pointer as
input but we have various types of mac addresse whose lengths
are up to MAX_ADDR_LEN, this is confusing.
Make it void like ->ndo_set_mac_address() and let callers check
its length before calling it. It is too late to fix dev_ifsioc()
due to API compatiblity, so just reject those larger than
sizeof(struct sockaddr).
This is also a preparation for the following patches.
Reported-by: Andrey Konovalov <andreyk...@google.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
include/linux/netdevice.h | 2 +-
net/core/dev.c | 10 +++++++---
net/core/dev_ioctl.c | 2 ++
3 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 97456b25..40e674c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3271,7 +3271,7 @@ int dev_set_alias(struct net_device *, const char *,
size_t);
int dev_change_net_namespace(struct net_device *, struct net *, const char *);
int dev_set_mtu(struct net_device *, int);
void dev_set_group(struct net_device *, int);
-int dev_set_mac_address(struct net_device *, struct sockaddr *);
+int dev_set_mac_address(struct net_device *, void *);
int dev_change_carrier(struct net_device *, bool new_carrier);
int dev_get_phys_port_id(struct net_device *dev,
struct netdev_phys_item_id *ppid);
diff --git a/net/core/dev.c b/net/core/dev.c
index 533a6d6..cc670e1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6610,13 +6610,17 @@ EXPORT_SYMBOL(dev_set_group);
/**
* dev_set_mac_address - Change Media Access Control Address
* @dev: device
- * @sa: new address
+ * @addr: new address, whose type could be either struct sockaddr or
+ * any other compatible type whose length is up to MAX_ADDR_LEN depending
+ * on the dev->addr_len. Callers should check if its length is smaller than
+ * dev->addr_len!!
*
* Change the hardware (MAC) address of the device
*/
-int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
+int dev_set_mac_address(struct net_device *dev, void *addr)
{
const struct net_device_ops *ops = dev->netdev_ops;
+ struct sockaddr *sa = addr;
int err;
if (!ops->ndo_set_mac_address)
@@ -6625,7 +6629,7 @@ int dev_set_mac_address(struct net_device *dev, struct
sockaddr *sa)
return -EINVAL;
if (!netif_device_present(dev))
return -ENODEV;
- err = ops->ndo_set_mac_address(dev, sa);
+ err = ops->ndo_set_mac_address(dev, addr);
if (err)
return err;
dev->addr_assign_type = NET_ADDR_SET;
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index b94b1d2..11f262e 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -261,6 +261,8 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr,
unsigned int cmd)
return dev_set_mtu(dev, ifr->ifr_mtu);
case SIOCSIFHWADDR:
+ if (dev->addr_len > sizeof(struct sockaddr))
+ return -EINVAL;
return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
case SIOCSIFHWBROADCAST:
--
2.5.5
