net: bridge: Fix locking in br_fdb_find_port()
authorPetr Machata <petrm@mellanox.com>
Fri, 8 Jun 2018 13:11:47 +0000 (15:11 +0200)
committerDavid S. Miller <davem@davemloft.net>
Fri, 8 Jun 2018 23:58:31 +0000 (19:58 -0400)
commit873aca2ee86e533665a73292c4e308ded1e9bafe
treeea70348861f364b709118946a5216a91cd421a00
parent6c206b20092a3623184cff9470dba75d21507874
net: bridge: Fix locking in br_fdb_find_port()

Callers of br_fdb_find() need to hold the hash lock, which
br_fdb_find_port() doesn't do. However, since br_fdb_find_port() is not
doing any actual FDB manipulation, the hash lock is not really needed at
all. So convert to br_fdb_find_rcu(), surrounded by rcu_read_lock() /
_unlock() pair.

The device pointer copied from inside the FDB entry is then kept alive
by the RTNL lock, which br_fdb_find_port() asserts.

Fixes: 4d4fd36126d6 ("net: bridge: Publish bridge accessor functions")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/bridge/br_fdb.c