Commit 9365fa51 authored by Ignat Korchagin's avatar Ignat Korchagin Committed by Jakub Kicinski
Browse files

net: inet: do not leave a dangling sk pointer in inet_create() 



sock_init_data() attaches the allocated sk object to the provided sock
object. If inet_create() fails later, the sk object is freed, but the
sock object retains the dangling pointer, which may create use-after-free
later.

Clear the sk pointer in the sock object on error.

Signed-off-by: default avatarIgnat Korchagin <ignat@cloudflare.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-7-ignat@cloudflare.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b4fcd63f

net/ipv4/af_inet.c

+10 −12
Original line number Diff line number Diff line
@@ -376,32 +376,30 @@ static int inet_create(struct net *net, struct socket *sock, int protocol, 
		inet->inet_sport = htons(inet->inet_num);

		/* Add to protocol hash chains. */

		err = sk->sk_prot->hash(sk);

		if (err) {

			sk_common_release(sk);

			goto out;

		}

		if (err)

			goto out_sk_release;

	}



	if (sk->sk_prot->init) {

		err = sk->sk_prot->init(sk);

		if (err) {

			sk_common_release(sk);

			goto out;

		}

		if (err)

			goto out_sk_release;

	}



	if (!kern) {

		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);

		if (err) {

			sk_common_release(sk);

			goto out;

		}

		if (err)

			goto out_sk_release;

	}

out:

	return err;

out_rcu_unlock:

	rcu_read_unlock();

	goto out;

out_sk_release:

	sk_common_release(sk);

	sock->sk = NULL;

	goto out;

}