ipv6: fix rtnl locking in setsockopt for anycast and multicast
Calling setsockopt with IPV6_JOIN_ANYCAST or IPV6_LEAVE_ANYCAST
triggers the assertion in addrconf_join_solict()/addrconf_leave_solict()
ipv6_sock_ac_join(), ipv6_sock_ac_drop(), ipv6_sock_ac_close() need to
take RTNL before calling ipv6_dev_ac_inc/dec. Same thing with
ipv6_sock_mc_join(), ipv6_sock_mc_drop(), ipv6_sock_mc_close() before
calling ipv6_dev_mc_inc/dec.
This patch moves ASSERT_RTNL() up a level in the call stack.
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reported-by: Tommi Rantala <tt.rantala@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 617f095..a23b655 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -172,6 +172,7 @@
mc_lst->next = NULL;
mc_lst->addr = *addr;
+ rtnl_lock();
rcu_read_lock();
if (ifindex == 0) {
struct rt6_info *rt;
@@ -185,6 +186,7 @@
if (dev == NULL) {
rcu_read_unlock();
+ rtnl_unlock();
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
return -ENODEV;
}
@@ -202,6 +204,7 @@
if (err) {
rcu_read_unlock();
+ rtnl_unlock();
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
return err;
}
@@ -212,6 +215,7 @@
spin_unlock(&ipv6_sk_mc_lock);
rcu_read_unlock();
+ rtnl_unlock();
return 0;
}
@@ -229,6 +233,7 @@
if (!ipv6_addr_is_multicast(addr))
return -EINVAL;
+ rtnl_lock();
spin_lock(&ipv6_sk_mc_lock);
for (lnk = &np->ipv6_mc_list;
(mc_lst = rcu_dereference_protected(*lnk,
@@ -252,12 +257,15 @@
} else
(void) ip6_mc_leave_src(sk, mc_lst, NULL);
rcu_read_unlock();
+ rtnl_unlock();
+
atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
kfree_rcu(mc_lst, rcu);
return 0;
}
}
spin_unlock(&ipv6_sk_mc_lock);
+ rtnl_unlock();
return -EADDRNOTAVAIL;
}
@@ -302,6 +310,7 @@
if (!rcu_access_pointer(np->ipv6_mc_list))
return;
+ rtnl_lock();
spin_lock(&ipv6_sk_mc_lock);
while ((mc_lst = rcu_dereference_protected(np->ipv6_mc_list,
lockdep_is_held(&ipv6_sk_mc_lock))) != NULL) {
@@ -328,6 +337,7 @@
spin_lock(&ipv6_sk_mc_lock);
}
spin_unlock(&ipv6_sk_mc_lock);
+ rtnl_unlock();
}
int ip6_mc_source(int add, int omode, struct sock *sk,
@@ -845,6 +855,8 @@
struct ifmcaddr6 *mc;
struct inet6_dev *idev;
+ ASSERT_RTNL();
+
/* we need to take a reference on idev */
idev = in6_dev_get(dev);
@@ -916,6 +928,8 @@
{
struct ifmcaddr6 *ma, **map;
+ ASSERT_RTNL();
+
write_lock_bh(&idev->lock);
for (map = &idev->mc_list; (ma=*map) != NULL; map = &ma->next) {
if (ipv6_addr_equal(&ma->mca_addr, addr)) {