From 1ac13efd614c752d3b47bbfb58e7c36eeb92cb5a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 8 Dec 2023 10:12:44 +0000 Subject: ipv6: annotate data-races around np->ucast_oif np->ucast_oif is read locklessly in some contexts. Make all accesses to this field lockless, adding appropriate annotations. This also makes setsockopt( IPV6_UNICAST_IF ) lockless. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/ipv6_sockglue.c | 58 ++++++++++++++++++++++-------------------------- 1 file changed, 26 insertions(+), 32 deletions(-) (limited to 'net/ipv6/ipv6_sockglue.c') diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index fe7e96e69960..9e8ebda170f1 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -537,6 +537,31 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, } WRITE_ONCE(np->mcast_oif, val); return 0; + case IPV6_UNICAST_IF: + { + struct net_device *dev; + int ifindex; + + if (optlen != sizeof(int)) + return -EINVAL; + + ifindex = (__force int)ntohl((__force __be32)val); + if (!ifindex) { + WRITE_ONCE(np->ucast_oif, 0); + return 0; + } + + dev = dev_get_by_index(net, ifindex); + if (!dev) + return -EADDRNOTAVAIL; + dev_put(dev); + + if (READ_ONCE(sk->sk_bound_dev_if)) + return -EINVAL; + + WRITE_ONCE(np->ucast_oif, ifindex); + return 0; + } } if (needs_rtnl) rtnl_lock(); @@ -857,37 +882,6 @@ done: break; } - - case IPV6_UNICAST_IF: - { - struct net_device *dev = NULL; - int ifindex; - - if (optlen != sizeof(int)) - goto e_inval; - - ifindex = (__force int)ntohl((__force __be32)val); - if (ifindex == 0) { - np->ucast_oif = 0; - retv = 0; - break; - } - - dev = dev_get_by_index(net, ifindex); - retv = -EADDRNOTAVAIL; - if (!dev) - break; - dev_put(dev); - - retv = -EINVAL; - if (sk->sk_bound_dev_if) - break; - - np->ucast_oif = ifindex; - retv = 0; - break; - } - case IPV6_ADD_MEMBERSHIP: case IPV6_DROP_MEMBERSHIP: { @@ -1369,7 +1363,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, break; case IPV6_UNICAST_IF: - val = (__force int)htonl((__u32) np->ucast_oif); + val = (__force int)htonl((__u32) READ_ONCE(np->ucast_oif)); break; case IPV6_MTU_DISCOVER: -- cgit