[PATCH net] openvswitch: Fix template leak in error cases.

From: Joe Stringer
Date: Wed Dec 23 2015 - 17:41:05 EST


Commit 5b48bb8506c5 ("openvswitch: Fix helper reference leak") fixed a
reference leak on helper objects, but inadvertently introduced a leak on
the ct template.

Previously, ct_info.ct->general.use was initialized to 0 by
nf_ct_tmpl_alloc() and only incremented when ovs_ct_copy_action()
returned successful. If an error occurred while adding the helper or
adding the action to the actions buffer, the __ovs_ct_free_action()
cleanup would use nf_ct_put() to free the entry; However, this relies on
atomic_dec_and_test(ct_info.ct->general.use). This reference must be
incremented first, or nf_ct_put() will never free it.

Fix the issue by acquiring a reference to the template immediately after
allocation.

Fixes: cae3a2627520 ("openvswitch: Allow attaching helpers to ct action")
Fixes: 5b48bb8506c5 ("openvswitch: Fix helper reference leak")
Signed-off-by: Joe Stringer <joe@xxxxxxx>
---
net/openvswitch/conntrack.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 8fc1bafc99fd..c6d8738d6970 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -683,6 +683,10 @@ int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
OVS_NLERR(log, "Failed to allocate conntrack template");
return -ENOMEM;
}
+
+ __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
+ nf_conntrack_get(&ct_info.ct->ct_general);
+
if (helper) {
err = ovs_ct_add_helper(&ct_info, helper, key, log);
if (err)
@@ -694,8 +698,6 @@ int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
if (err)
goto err_free_ct;

- __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
- nf_conntrack_get(&ct_info.ct->ct_general);
return 0;
err_free_ct:
__ovs_ct_free_action(&ct_info);
--
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/