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>
This commit is contained in:
David S. Miller
2011-01-05 15:38:53 -08:00
parent 44b8288308
commit 3610cda53f
6 changed files with 22 additions and 24 deletions
+1 -1
View File
@@ -548,7 +548,7 @@ static int cap_sem_semop(struct sem_array *sma, struct sembuf *sops,
}
#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;
+1 -2
View File
@@ -977,8 +977,7 @@ EXPORT_SYMBOL(security_inode_getsecctx);
#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);
}
+5 -5
View File
@@ -3921,18 +3921,18 @@ static int selinux_socket_shutdown(struct socket *sock, int how)
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,
+7 -7
View File
@@ -2408,22 +2408,22 @@ static int smack_setprocattr(struct task_struct *p, char *name,
/**
* 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);
}