[PATCH] net: netfilter: fix possible refcount leak in ctnetlink_create_conntrack()

From: Hangyu Hua
Date: Fri Feb 10 2023 - 02:17:44 EST


nf_ct_put() needs to be called to put the refcount got by
nf_conntrack_find_get() to avoid refcount leak when
nf_conntrack_hash_check_insert() fails.

Fixes: 7d367e06688d ("netfilter: ctnetlink: fix soft lockup when netlink adds new entries (v2)")
Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
---
net/netfilter/nf_conntrack_netlink.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 1286ae7d4609..ca4d5bb1ea52 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -2375,12 +2375,15 @@ ctnetlink_create_conntrack(struct net *net,

err = nf_conntrack_hash_check_insert(ct);
if (err < 0)
- goto err2;
+ goto err3;

rcu_read_unlock();

return ct;

+err3:
+ if (ct->master)
+ nf_ct_put(ct->master);
err2:
rcu_read_unlock();
err1:
--
2.34.1