net: openvswitch: Fix Use-After-Free in ovs_ct_exit

Since kfree_rcu, which is called in the hlist_for_each_entry_rcu traversal
of ovs_ct_limit_exit, is not part of the RCU read critical section, it
is possible that the RCU grace period will pass during the traversal and
the key will be free.

To prevent this, it should be changed to hlist_for_each_entry_safe.

Fixes: 11efd5cb04 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Hyunwoo Kim <v4bel@theori.io>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/ZiYvzQN/Ry5oeFQW@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Hyunwoo Kim 2024-04-22 05:37:17 -04:00 committed by Jakub Kicinski
parent 5b5f724b05
commit 5ea7b72d4f
1 changed files with 2 additions and 2 deletions

View File

@ -1593,9 +1593,9 @@ static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
struct hlist_head *head = &info->limits[i];
struct ovs_ct_limit *ct_limit;
struct hlist_node *next;
hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
lockdep_ovsl_is_held())
hlist_for_each_entry_safe(ct_limit, next, head, hlist_node)
kfree_rcu(ct_limit, rcu);
}
kfree(info->limits);