diff options
| author | WANG Cong | 2017-07-26 15:22:06 -0700 |
|---|---|---|
| committer | David S. Miller | 2017-07-29 11:25:05 -0700 |
| commit | 0254e0c632bfe4a0cf610e2d90397474144f00d2 (patch) | |
| tree | 80b3164f82ae010a864fff268ffc5c1fb40119b9 /net | |
| parent | 245db3c349e0b413e0fec8d6179f6b767649ad63 (diff) | |
net: check dev->addr_len for dev_set_mac_address()
Historically, dev_ifsioc() uses struct sockaddr as mac
address definition, this is why dev_set_mac_address()
accepts a struct sockaddr pointer as input but now we
have various types of mac addresse whose lengths
are up to MAX_ADDR_LEN, longer than struct sockaddr,
and saved in dev->addr_len.
It is too late to fix dev_ifsioc() due to API
compatibility, so just reject those larger than
sizeof(struct sockaddr), otherwise we would read
and use some random bytes from kernel stack.
Fortunately, only a few IPv6 tunnel devices have addr_len
larger than sizeof(struct sockaddr) and they don't support
ndo_set_mac_addr(). But with team driver, in lb mode, they
can still be enslaved to a team master and make its mac addr
length as the same.
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev_ioctl.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index 06b147d7d9e2..709a4e6fb447 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -263,6 +263,8 @@ 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: |