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/capability.c b/security/capability.c
index c773635..2a5df2b 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -548,7 +548,7 @@
}
#ifdef CONFIG_SECURITY_NETWORK
-static int cap_unix_stream_connect(struct socket *sock, struct socket *other,
+static int cap_unix_stream_connect(struct sock *sock, struct sock *other,
struct sock *newsk)
{
return 0;
diff --git a/security/security.c b/security/security.c
index 1b798d3..e5fb07a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -977,8 +977,7 @@
#ifdef CONFIG_SECURITY_NETWORK
-int security_unix_stream_connect(struct socket *sock, struct socket *other,
- struct sock *newsk)
+int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk)
{
return security_ops->unix_stream_connect(sock, other, newsk);
}
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,
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 489a85a..ccb71a0 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2408,22 +2408,22 @@
/**
* smack_unix_stream_connect - Smack access on UDS
- * @sock: one socket
- * @other: the other socket
+ * @sock: one sock
+ * @other: the other sock
* @newsk: unused
*
* Return 0 if a subject with the smack of sock could access
* an object with the smack of other, otherwise an error code
*/
-static int smack_unix_stream_connect(struct socket *sock,
- struct socket *other, struct sock *newsk)
+static int smack_unix_stream_connect(struct sock *sock,
+ struct sock *other, struct sock *newsk)
{
- struct inode *sp = SOCK_INODE(sock);
- struct inode *op = SOCK_INODE(other);
+ struct inode *sp = SOCK_INODE(sock->sk_socket);
+ struct inode *op = SOCK_INODE(other->sk_socket);
struct smk_audit_info ad;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
- smk_ad_setfield_u_net_sk(&ad, other->sk);
+ smk_ad_setfield_u_net_sk(&ad, other);
return smk_access(smk_of_inode(sp), smk_of_inode(op),
MAY_READWRITE, &ad);
}