From c624f777485ab9c7cd034d68a796ff86b746257f Mon Sep 17 00:00:00 2001 From: Hyunwoo Kim Date: Thu, 16 May 2024 16:49:58 +0800 Subject: [PATCH] net: openvswitch: Fix Use-After-Free in ovs_ct_exit [ Upstream commit 5ea7b72d4fac2fdbc0425cd8f2ea33abe95235b2 ] 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: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit") Signed-off-by: Hyunwoo Kim Reviewed-by: Eric Dumazet Reviewed-by: Aaron Conole Link: https://lore.kernel.org/r/ZiYvzQN/Ry5oeFQW@v4bel-B760M-AORUS-ELITE-AX Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Conflicts: net/openvswitch/conntrack.c [The conflict occurs because commit 27de77cec985("net: openvswitch: ovs_ct_exit to be done under ovs_lock") is not merged.] Signed-off-by: Zhengchao Shao --- net/openvswitch/conntrack.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index 90462f58e991..5c11139d3c65 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -1841,8 +1841,9 @@ 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) + hlist_for_each_entry_safe(ct_limit, next, head, hlist_node) kfree_rcu(ct_limit, rcu); } kfree(ovs_net->ct_limit_info->limits); -- Gitee