[PATCH 5.4 144/214] macvlan: validate setting of multiple remote source MAC addresses

Greg Kroah-Hartman
2020-09-01T16:20:43Z

From: Alvin Šipraga <alsi@bang-olufsen.dk>

[ Upstream commit 8b61fba503904acae24aeb2bd5569b4d6544d48f ]

Remote source MAC addresses can be set on a 'source mode' macvlan
interface via the IFLA_MACVLAN_MACADDR_DATA attribute. This commit
tightens the validation of these MAC addresses to match the validation
already performed when setting or adding a single MAC address via the
IFLA_MACVLAN_MACADDR attribute.

iproute2 uses IFLA_MACVLAN_MACADDR_DATA for its 'macvlan macaddr set'
command, and IFLA_MACVLAN_MACADDR for its 'macvlan macaddr add' command,
which demonstrates the inconsistent behaviour that this commit
addresses:

# ip link add link eth0 name macvlan0 type macvlan mode source
# ip link set link dev macvlan0 type macvlan macaddr add 01:00:00:00:00:00
RTNETLINK answers: Cannot assign requested address
# ip link set link dev macvlan0 type macvlan macaddr set 01:00:00:00:00:00
# ip -d link show macvlan0
5: macvlan0@eth0: <BROADCAST,MULTICAST,DYNAMIC,UP,LOWER_UP> mtu 1500 ...
link/ether 2e:ac:fd:2d:69:f8 brd ff:ff:ff:ff:ff:ff promiscuity 0
macvlan mode source remotes (1) 01:00:00:00:00:00 numtxqueues 1 ...

With this change, the 'set' command will (rightly) fail in the same way
as the 'add' command.

Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/macvlan.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 9d3209ae41cfb..07622cf8765ae 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1259,6 +1259,9 @@ static void macvlan_port_destroy(struct net_device *dev)
static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
+ struct nlattr *nla, *head;
+ int rem, len;
+
if (tb[IFLA_ADDRESS]) {
if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
return -EINVAL;
@@ -1306,6 +1309,20 @@ static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[],
return -EADDRNOTAVAIL;
}

+ if (data[IFLA_MACVLAN_MACADDR_DATA]) {
+ head = nla_data(data[IFLA_MACVLAN_MACADDR_DATA]);
+ len = nla_len(data[IFLA_MACVLAN_MACADDR_DATA]);
+
+ nla_for_each_attr(nla, head, len, rem) {
+ if (nla_type(nla) != IFLA_MACVLAN_MACADDR ||
+ nla_len(nla) != ETH_ALEN)
+ return -EINVAL;
+
+ if (!is_valid_ether_addr(nla_data(nla)))
+ return -EADDRNOTAVAIL;
+ }
+ }
+
if (data[IFLA_MACVLAN_MACADDR_COUNT])
return -EINVAL;

@@ -1362,10 +1379,6 @@ static int macvlan_changelink_sources(struct macvlan_dev *vlan, u32 mode,
len = nla_len(data[IFLA_MACVLAN_MACADDR_DATA]);

nla_for_each_attr(nla, head, len, rem) {
- if (nla_type(nla) != IFLA_MACVLAN_MACADDR ||
- nla_len(nla) != ETH_ALEN)
- continue;
-
addr = nla_data(nla);
ret = macvlan_hash_add_source(vlan, addr);
if (ret)
--
2.25.1