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Commit b7f47c79 authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman
Browse files

ping: implement proper locking 

commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream.

We got a report of yet another bug in ping

http://www.openwall.com/lists/oss-security/2017/03/24/6



->disconnect() is not called with socket lock held.

Fix this by acquiring ping rwlock earlier.

Thanks to Daniel, Alexander and Andrey for letting us know this problem.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarDaniel Jiang <danieljiang0415@gmail.com>
Reported-by: default avatarSolar Designer <solar@openwall.com>
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a7544fdd

net/ipv4/ping.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -154,17 +154,18 @@ void ping_hash(struct sock *sk) 
void ping_unhash(struct sock *sk)

void ping_unhash(struct sock *sk)

{

{

	struct inet_sock *isk = inet_sk(sk);

	struct inet_sock *isk = inet_sk(sk);



	pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);

	pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);

	if (sk_hashed(sk)) {

	write_lock_bh(&ping_table.lock);

	write_lock_bh(&ping_table.lock);

	if (sk_hashed(sk)) {

		hlist_nulls_del(&sk->sk_nulls_node);

		hlist_nulls_del(&sk->sk_nulls_node);

		sk_nulls_node_init(&sk->sk_nulls_node);

		sk_nulls_node_init(&sk->sk_nulls_node);

		sock_put(sk);

		sock_put(sk);

		isk->inet_num = 0;

		isk->inet_num = 0;

		isk->inet_sport = 0;

		isk->inet_sport = 0;

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

		write_unlock_bh(&ping_table.lock);

	}

	}

	write_unlock_bh(&ping_table.lock);

}

}

EXPORT_SYMBOL_GPL(ping_unhash);

EXPORT_SYMBOL_GPL(ping_unhash);