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authorEric Dumazet <edumazet@google.com>2023-12-08 10:12:43 +0000
committerDavid S. Miller <davem@davemloft.net>2023-12-11 10:59:17 +0000
commitd2f011a0bf28c090ad75c9b1d306f2e1dda1c9bc (patch)
tree672849531d60dae088df5508f6183ea01231b6ae /net/ipv6/ipv6_sockglue.c
parent9a64d4c93eee6b2efb7a02ec98d9480946424509 (diff)
ipv6: annotate data-races around np->mcast_oif
np->mcast_oif is read locklessly in some contexts. Make all accesses to this field lockless, adding appropriate annotations. This also makes setsockopt( IPV6_MULTICAST_IF ) lockless. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/ipv6_sockglue.c')
-rw-r--r--net/ipv6/ipv6_sockglue.c74
1 files changed, 38 insertions, 36 deletions
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 7d661735cb9d..fe7e96e69960 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -509,6 +509,34 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
if (optlen < sizeof(int))
return -EINVAL;
return ip6_sock_set_addr_preferences(sk, val);
+ case IPV6_MULTICAST_IF:
+ if (sk->sk_type == SOCK_STREAM)
+ return -ENOPROTOOPT;
+ if (optlen < sizeof(int))
+ return -EINVAL;
+ if (val) {
+ struct net_device *dev;
+ int bound_dev_if, midx;
+
+ rcu_read_lock();
+
+ dev = dev_get_by_index_rcu(net, val);
+ if (!dev) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+ midx = l3mdev_master_ifindex_rcu(dev);
+
+ rcu_read_unlock();
+
+ bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+ if (bound_dev_if &&
+ bound_dev_if != val &&
+ (!midx || midx != bound_dev_if))
+ return -EINVAL;
+ }
+ WRITE_ONCE(np->mcast_oif, val);
+ return 0;
}
if (needs_rtnl)
rtnl_lock();
@@ -860,36 +888,6 @@ done:
break;
}
- case IPV6_MULTICAST_IF:
- if (sk->sk_type == SOCK_STREAM)
- break;
- if (optlen < sizeof(int))
- goto e_inval;
-
- if (val) {
- struct net_device *dev;
- int midx;
-
- rcu_read_lock();
-
- dev = dev_get_by_index_rcu(net, val);
- if (!dev) {
- rcu_read_unlock();
- retv = -ENODEV;
- break;
- }
- midx = l3mdev_master_ifindex_rcu(dev);
-
- rcu_read_unlock();
-
- if (sk->sk_bound_dev_if &&
- sk->sk_bound_dev_if != val &&
- (!midx || midx != sk->sk_bound_dev_if))
- goto e_inval;
- }
- np->mcast_oif = val;
- retv = 0;
- break;
case IPV6_ADD_MEMBERSHIP:
case IPV6_DROP_MEMBERSHIP:
{
@@ -1161,10 +1159,12 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
sockopt_release_sock(sk);
if (!skb) {
if (np->rxopt.bits.rxinfo) {
+ int mcast_oif = READ_ONCE(np->mcast_oif);
struct in6_pktinfo src_info;
- src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
+
+ src_info.ipi6_ifindex = mcast_oif ? :
np->sticky_pktinfo.ipi6_ifindex;
- src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
+ src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
}
if (np->rxopt.bits.rxhlim) {
@@ -1178,11 +1178,13 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
}
if (np->rxopt.bits.rxoinfo) {
+ int mcast_oif = READ_ONCE(np->mcast_oif);
struct in6_pktinfo src_info;
- src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
+
+ src_info.ipi6_ifindex = mcast_oif ? :
np->sticky_pktinfo.ipi6_ifindex;
- src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :
- np->sticky_pktinfo.ipi6_addr;
+ src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr :
+ np->sticky_pktinfo.ipi6_addr;
put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
}
if (np->rxopt.bits.rxohlim) {
@@ -1359,7 +1361,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
break;
case IPV6_MULTICAST_IF:
- val = np->mcast_oif;
+ val = READ_ONCE(np->mcast_oif);
break;
case IPV6_MULTICAST_ALL: