[PATCH 5.7 010/265] net: bridge: enfore alignment for ethernet address

Sasha Levin
2020-06-29T21:31:38Z

From: Thomas Martitz <t.martitz@avm.de>

[ Upstream commit db7202dec92e6caa2706c21d6fc359af318bde2e ]

The eth_addr member is passed to ether_addr functions that require
2-byte alignment, therefore the member must be properly aligned
to avoid unaligned accesses.

The problem is in place since the initial merge of multicast to unicast:
commit 6db6f0eae6052b70885562e1733896647ec1d807 bridge: multicast to unicast

Fixes: 6db6f0eae605 ("bridge: multicast to unicast")
Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Martitz <t.martitz@avm.de>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/br_private.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 1f97703a52ffb..18430f79ac37e 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -217,8 +217,8 @@ struct net_bridge_port_group {
struct rcu_head rcu;
struct timer_list timer;
struct br_ip addr;
+ unsigned char eth_addr[ETH_ALEN] __aligned(2);
unsigned char flags;
- unsigned char eth_addr[ETH_ALEN];
};

struct net_bridge_mdb_entry {
--
2.25.1