diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-02-16 10:01:49 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-02-17 17:11:08 -0800 |
| commit | ad5dfde2a5733aaf652ea3e40c8c5e071e935901 (patch) | |
| tree | 44180d06108bab2998e5a774877992589995a82e | |
| parent | 458c95de5c55c05b7a149da1509f4f0f68d28625 (diff) | |
ping: annotate data-races in ping_lookup()
isk->inet_num, isk->inet_rcv_saddr and sk->sk_bound_dev_if
are read locklessly in ping_lookup().
Add READ_ONCE()/WRITE_ONCE() annotations.
The race on isk->inet_rcv_saddr is probably coming from IPv6 support,
but does not deserve a specific backport.
Fixes: dbca1596bbb0 ("ping: convert to RCU lookups, get rid of rwlock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260216100149.3319315-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/ping.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index ebfc5a3d3ad6..71d5e17719de 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -148,7 +148,7 @@ void ping_unhash(struct sock *sk) pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); spin_lock(&ping_table.lock); if (sk_del_node_init_rcu(sk)) { - isk->inet_num = 0; + WRITE_ONCE(isk->inet_num, 0); isk->inet_sport = 0; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); } @@ -181,31 +181,35 @@ static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) } sk_for_each_rcu(sk, hslot) { + int bound_dev_if; + if (!net_eq(sock_net(sk), net)) continue; isk = inet_sk(sk); pr_debug("iterate\n"); - if (isk->inet_num != ident) + if (READ_ONCE(isk->inet_num) != ident) continue; + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); if (skb->protocol == htons(ETH_P_IP) && sk->sk_family == AF_INET) { + __be32 rcv_saddr = READ_ONCE(isk->inet_rcv_saddr); + pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, - (int) isk->inet_num, &isk->inet_rcv_saddr, - sk->sk_bound_dev_if); + ident, &rcv_saddr, + bound_dev_if); - if (isk->inet_rcv_saddr && - isk->inet_rcv_saddr != ip_hdr(skb)->daddr) + if (rcv_saddr && rcv_saddr != ip_hdr(skb)->daddr) continue; #if IS_ENABLED(CONFIG_IPV6) } else if (skb->protocol == htons(ETH_P_IPV6) && sk->sk_family == AF_INET6) { pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, - (int) isk->inet_num, + ident, &sk->sk_v6_rcv_saddr, - sk->sk_bound_dev_if); + bound_dev_if); if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, @@ -216,8 +220,8 @@ static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) continue; } - if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && - sk->sk_bound_dev_if != sdif) + if (bound_dev_if && bound_dev_if != dif && + bound_dev_if != sdif) continue; goto exit; @@ -392,7 +396,9 @@ static void ping_set_saddr(struct sock *sk, struct sockaddr_unsized *saddr) if (saddr->sa_family == AF_INET) { struct inet_sock *isk = inet_sk(sk); struct sockaddr_in *addr = (struct sockaddr_in *) saddr; - isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; + + isk->inet_saddr = addr->sin_addr.s_addr; + WRITE_ONCE(isk->inet_rcv_saddr, addr->sin_addr.s_addr); #if IS_ENABLED(CONFIG_IPV6) } else if (saddr->sa_family == AF_INET6) { struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; @@ -850,7 +856,8 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, struct sk_buff *skb; int copied, err; - pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); + pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, + READ_ONCE(isk->inet_num)); err = -EOPNOTSUPP; if (flags & MSG_OOB) |