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ipvs: call rtnl_lock early
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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 54ff9ef
("ipv4, ipv6: kill ip_mc_{join, leave}_group and
ipv6_sock_mc_{join, drop}").

Signed-off-by: Julian Anastasov <[email protected]>
Signed-off-by: Simon Horman <[email protected]>
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Julian Anastasov authored and horms committed Aug 21, 2015
1 parent eefa32d commit e0b26cc
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Showing 2 changed files with 33 additions and 19 deletions.
50 changes: 33 additions & 17 deletions net/netfilter/ipvs/ip_vs_ctl.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

Expand Down Expand Up @@ -3342,6 +3347,9 @@ static int ip_vs_genl_dump_daemons(struct sk_buff *skb,

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]))
Expand All @@ -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)
Expand All @@ -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;

Expand All @@ -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;
}

Expand Down
2 changes: 0 additions & 2 deletions net/netfilter/ipvs/ip_vs_sync.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}
Expand Down

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