af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.
unix_release() can asynchornously set socket->sk to NULL, and
it does so without holding the unix_state_lock() on "other"
during stream connects.
However, the reverse mapping, sk->sk_socket, is only transitioned
to NULL under the unix_state_lock().
Therefore make the security hooks follow the reverse mapping instead
of the forward mapping.
Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c82538a..6f637d2 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3921,18 +3921,18 @@
return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
}
-static int selinux_socket_unix_stream_connect(struct socket *sock,
- struct socket *other,
+static int selinux_socket_unix_stream_connect(struct sock *sock,
+ struct sock *other,
struct sock *newsk)
{
- struct sk_security_struct *sksec_sock = sock->sk->sk_security;
- struct sk_security_struct *sksec_other = other->sk->sk_security;
+ struct sk_security_struct *sksec_sock = sock->sk_security;
+ struct sk_security_struct *sksec_other = other->sk_security;
struct sk_security_struct *sksec_new = newsk->sk_security;
struct common_audit_data ad;
int err;
COMMON_AUDIT_DATA_INIT(&ad, NET);
- ad.u.net.sk = other->sk;
+ ad.u.net.sk = other;
err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
sksec_other->sclass,