This is a note to let you know that I've just added the patch titled
net: openvswitch: Fix Use-After-Free in ovs_ct_exit
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-openvswitch-fix-use-after-free-in-ovs_ct_exit.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f70a90fd8a682f15537c3b2eaae8c44148136562
Author: Hyunwoo Kim <v4bel@xxxxxxxxx>
Date: Mon Apr 22 05:37:17 2024 -0400
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 <v4bel@xxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Aaron Conole <aconole@xxxxxxxxxx>
Link: https://lore.kernel.org/r/ZiYvzQN/Ry5oeFQW@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 352e80e6cd75c..3ea1e5ffaf80d 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1836,9 +1836,9 @@ 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(ovs_net->ct_limit_info->limits);
