When the sync damon is started we need to hold rtnl
lock while calling ip_mc_join_group. Currently, we have
a wrong locking order because the correct one is
rtnl_lock->__ip_vs_mutex. It is implied from the usage
of __ip_vs_mutex in ip_vs_dst_event() which is called
under rtnl lock during NETDEV_* notifications.
Fix the problem by calling rtnl_lock early only for the
start_sync_thread call. As a bonus this fixes the usage
__dev_get_by_name which was not called under rtnl lock.
This patch actually extends and depends on commit 54ff9ef36bdf
("ipv4, ipv6: kill ip_mc_{join, leave}_group and
ipv6_sock_mc_{join, drop}").
Signed-off-by: Julian Anastasov <ja@xxxxxx>
---
net/netfilter/ipvs/ip_vs_ctl.c | 50 +++++++++++++++++++++++++++--------------
net/netfilter/ipvs/ip_vs_sync.c | 2 --
2 files changed, 33 insertions(+), 19 deletions(-)
Works on 4.1+ becase commit 54ff9ef36bdf is present only there.
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 24c5542..af0b69e 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2335,13 +2335,18 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
cmd == IP_VS_SO_SET_STOPDAEMON) {
struct ip_vs_daemon_user *dm = (struct ip_vs_daemon_user *)arg;
- mutex_lock(&ipvs->sync_mutex);
- if (cmd == IP_VS_SO_SET_STARTDAEMON)
+ if (cmd == IP_VS_SO_SET_STARTDAEMON) {
+ rtnl_lock();
+ mutex_lock(&ipvs->sync_mutex);
ret = start_sync_thread(net, dm->state, dm->mcast_ifn,
dm->syncid);
- else
+ mutex_unlock(&ipvs->sync_mutex);
+ rtnl_unlock();
+ } else {
+ mutex_lock(&ipvs->sync_mutex);
ret = stop_sync_thread(net, dm->state);
- mutex_unlock(&ipvs->sync_mutex);
+ mutex_unlock(&ipvs->sync_mutex);
+ }
goto out_dec;
}
@@ -3342,6 +3347,9 @@ nla_put_failure:
static int ip_vs_genl_new_daemon(struct net *net, struct nlattr **attrs)
{
+ struct netns_ipvs *ipvs = net_ipvs(net);
+ int ret;
+
if (!(attrs[IPVS_DAEMON_ATTR_STATE] &&
attrs[IPVS_DAEMON_ATTR_MCAST_IFN] &&
attrs[IPVS_DAEMON_ATTR_SYNC_ID]))
@@ -3353,19 +3361,30 @@ static int ip_vs_genl_new_daemon(struct net *net, struct nlattr **attrs)
if (net_ipvs(net)->mixed_address_family_dests > 0)
return -EINVAL;
- return start_sync_thread(net,
- nla_get_u32(attrs[IPVS_DAEMON_ATTR_STATE]),
- nla_data(attrs[IPVS_DAEMON_ATTR_MCAST_IFN]),
- nla_get_u32(attrs[IPVS_DAEMON_ATTR_SYNC_ID]));
+ rtnl_lock();
+ mutex_lock(&ipvs->sync_mutex);
+ ret = start_sync_thread(net,
+ nla_get_u32(attrs[IPVS_DAEMON_ATTR_STATE]),
+ nla_data(attrs[IPVS_DAEMON_ATTR_MCAST_IFN]),
+ nla_get_u32(attrs[IPVS_DAEMON_ATTR_SYNC_ID]));
+ mutex_unlock(&ipvs->sync_mutex);
+ rtnl_unlock();
+ return ret;
}
static int ip_vs_genl_del_daemon(struct net *net, struct nlattr **attrs)
{
+ struct netns_ipvs *ipvs = net_ipvs(net);
+ int ret;
+
if (!attrs[IPVS_DAEMON_ATTR_STATE])
return -EINVAL;
- return stop_sync_thread(net,
- nla_get_u32(attrs[IPVS_DAEMON_ATTR_STATE]));
+ mutex_lock(&ipvs->sync_mutex);
+ ret = stop_sync_thread(net,
+ nla_get_u32(attrs[IPVS_DAEMON_ATTR_STATE]));
+ mutex_unlock(&ipvs->sync_mutex);
+ return ret;
}
static int ip_vs_genl_set_config(struct net *net, struct nlattr **attrs)
@@ -3389,7 +3408,7 @@ static int ip_vs_genl_set_config(struct net *net, struct nlattr **attrs)
static int ip_vs_genl_set_daemon(struct sk_buff *skb, struct genl_info *info)
{
- int ret = 0, cmd;
+ int ret = -EINVAL, cmd;
struct net *net;
struct netns_ipvs *ipvs;
@@ -3400,22 +3419,19 @@ static int ip_vs_genl_set_daemon(struct sk_buff *skb, struct genl_info *info)
if (cmd == IPVS_CMD_NEW_DAEMON || cmd == IPVS_CMD_DEL_DAEMON) {
struct nlattr *daemon_attrs[IPVS_DAEMON_ATTR_MAX + 1];
- mutex_lock(&ipvs->sync_mutex);
if (!info->attrs[IPVS_CMD_ATTR_DAEMON] ||
nla_parse_nested(daemon_attrs, IPVS_DAEMON_ATTR_MAX,
info->attrs[IPVS_CMD_ATTR_DAEMON],
- ip_vs_daemon_policy)) {
- ret = -EINVAL;
+ ip_vs_daemon_policy))
goto out;
- }
if (cmd == IPVS_CMD_NEW_DAEMON)
ret = ip_vs_genl_new_daemon(net, daemon_attrs);
else
ret = ip_vs_genl_del_daemon(net, daemon_attrs);
-out:
- mutex_unlock(&ipvs->sync_mutex);
}
+
+out:
return ret;
}
diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index d99ad93..6bc6dca 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -1405,11 +1405,9 @@ join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
mreq.imr_ifindex = dev->ifindex;
- rtnl_lock();
lock_sock(sk);
ret = ip_mc_join_group(sk, &mreq);
release_sock(sk);
- rtnl_unlock();
return ret;
}
--
1.9.3
--
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