Commit 7d8d93fd authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

net: Restrict SO_PASS{CRED,PIDFD,SEC} to AF_{UNIX,NETLINK,BLUETOOTH}. 



SCM_CREDENTIALS and SCM_SECURITY can be recv()ed by calling
scm_recv() or scm_recv_unix(), and SCM_PIDFD is only used by
scm_recv_unix().

scm_recv() is called from AF_NETLINK and AF_BLUETOOTH.

scm_recv_unix() is literally called from AF_UNIX.

Let's restrict SO_PASSCRED and SO_PASSSEC to such sockets and
SO_PASSPIDFD to AF_UNIX only.

Later, SOCK_PASS{CRED,PIDFD,SEC} will be moved to struct sock
and united with another field.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ae4f2f59

include/net/sock.h

+13 −1
Original line number Diff line number Diff line
@@ -2773,9 +2773,14 @@ static inline bool sk_is_udp(const struct sock *sk) 
	       sk->sk_protocol == IPPROTO_UDP;

}



static inline bool sk_is_unix(const struct sock *sk)

{

	return sk->sk_family == AF_UNIX;

}



static inline bool sk_is_stream_unix(const struct sock *sk)

{

	return sk->sk_family == AF_UNIX && sk->sk_type == SOCK_STREAM;

	return sk_is_unix(sk) && sk->sk_type == SOCK_STREAM;

}



static inline bool sk_is_vsock(const struct sock *sk)
@@ -2783,6 +2788,13 @@ static inline bool sk_is_vsock(const struct sock *sk) 
	return sk->sk_family == AF_VSOCK;

}



static inline bool sk_may_scm_recv(const struct sock *sk)

{

	return (IS_ENABLED(CONFIG_UNIX) && sk->sk_family == AF_UNIX) ||

		sk->sk_family == AF_NETLINK ||

		(IS_ENABLED(CONFIG_BT) && sk->sk_family == AF_BLUETOOTH);

}



/**

 * sk_eat_skb - Release a skb if it is no longer needed

 * @sk: socket to eat this skb from

net/core/sock.c

+18 −0
Original line number Diff line number Diff line
@@ -1221,12 +1221,21 @@ int sk_setsockopt(struct sock *sk, int level, int optname, 
		}

		return -EPERM;

	case SO_PASSSEC:

		if (!IS_ENABLED(CONFIG_SECURITY_NETWORK) || sk_may_scm_recv(sk))

			return -EOPNOTSUPP;



		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);

		return 0;

	case SO_PASSCRED:

		if (!sk_may_scm_recv(sk))

			return -EOPNOTSUPP;



		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);

		return 0;

	case SO_PASSPIDFD:

		if (!sk_is_unix(sk))

			return -EOPNOTSUPP;



		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);

		return 0;

	case SO_TYPE:
@@ -1855,10 +1864,16 @@ int sk_getsockopt(struct sock *sk, int level, int optname, 
		break;



	case SO_PASSCRED:

		if (!sk_may_scm_recv(sk))

			return -EOPNOTSUPP;



		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);

		break;



	case SO_PASSPIDFD:

		if (!sk_is_unix(sk))

			return -EOPNOTSUPP;



		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);

		break;
@@ -1956,6 +1971,9 @@ int sk_getsockopt(struct sock *sk, int level, int optname, 
		break;



	case SO_PASSSEC:

		if (!IS_ENABLED(CONFIG_SECURITY_NETWORK) || !sk_may_scm_recv(sk))

			return -EOPNOTSUPP;



		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);

		break;