]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
[BRIDGE]: Fix fdb RCU race
authorPatrick McHardy <kaber@trash.net>
Thu, 22 Mar 2007 19:25:20 +0000 (12:25 -0700)
committerDavid S. Miller <davem@davemloft.net>
Thu, 22 Mar 2007 19:25:20 +0000 (12:25 -0700)
commitb19cbe2a1695c09c74f83646c4b82b51123b3690
tree138761d3360b981292569e318757e53502f8887b
parentec25615b9ddd5c584b4066652840581fdb6c5e7a
[BRIDGE]: Fix fdb RCU race

br_fdb_get use atomic_inc to increase the refcount of an element found
on a RCU protected list, which can lead to the following race:

CPU0 CPU1

br_fdb_get:   rcu_read_lock
__br_fdb_get: find element
fdb_delete:   hlist_del_rcu
      br_fdb_put
br_fdb_put:   atomic_dec_and_test
      call_rcu(fdb_rcu_free) br_fdb_get:   atomic_inc
      rcu_read_unlock
fdb_rcu_free: kmem_cache_free

Use atomic_inc_not_zero instead.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/bridge/br_fdb.c