[PATCH 6.1 230/232] inet: ping: check sock_net() in ping_get_port() and ping_lookup()

Sasha Levin
2026-02-28T18:14:43Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 59f26d86b2a16f1406f3b42025062b6d1fba5dd5 ]

We need to check socket netns before considering them in ping_get_port().
Otherwise, one malicious netns could 'consume' all ports.

Add corresponding check in ping_lookup().

Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://patch.msgid.link/20250829153054.474201-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: ad5dfde2a573 ("ping: annotate data-races in ping_lookup()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/ping.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index aae5ad6303a97..ee0e2df5d62e0 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -77,6 +77,7 @@ static inline struct hlist_head *ping_hashslot(struct ping_table *table,

int ping_get_port(struct sock *sk, unsigned short ident)
{
+ struct net *net = sock_net(sk);
struct inet_sock *isk, *isk2;
struct hlist_head *hlist;
struct sock *sk2 = NULL;
@@ -90,9 +91,10 @@ int ping_get_port(struct sock *sk, unsigned short ident)
for (i = 0; i < (1L << 16); i++, result++) {
if (!result)
result++; /* avoid zero */
- hlist = ping_hashslot(&ping_table, sock_net(sk),
- result);
+ hlist = ping_hashslot(&ping_table, net, result);
sk_for_each(sk2, hlist) {
+ if (!net_eq(sock_net(sk2), net))
+ continue;
isk2 = inet_sk(sk2);

if (isk2->inet_num == result)
@@ -108,8 +110,10 @@ int ping_get_port(struct sock *sk, unsigned short ident)
if (i >= (1L << 16))
goto fail;
} else {
- hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
+ hlist = ping_hashslot(&ping_table, net, ident);
sk_for_each(sk2, hlist) {
+ if (!net_eq(sock_net(sk2), net))
+ continue;
isk2 = inet_sk(sk2);

/* BUG? Why is this reuse and not reuseaddr? ping.c
@@ -129,7 +133,7 @@ int ping_get_port(struct sock *sk, unsigned short ident)
pr_debug("was not hashed\n");
sk_add_node_rcu(sk, hlist);
sock_set_flag(sk, SOCK_RCU_FREE);
- sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+ sock_prot_inuse_add(net, sk->sk_prot, 1);
}
spin_unlock(&ping_table.lock);
return 0;
@@ -188,6 +192,8 @@ static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
}

sk_for_each_rcu(sk, hslot) {
+ if (!net_eq(sock_net(sk), net))
+ continue;
isk = inet_sk(sk);

pr_debug("iterate\n");
--
2.51.0