diff options
| -rw-r--r-- | security/selinux/hooks.c | 68 |
1 files changed, 53 insertions, 15 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 4e7c02e3c3cd..d32db4140aa0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3734,6 +3734,30 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) return 0; } +/** + * selinux_conn_sid - Determine the child socket label for a connection + * @sk_sid: the parent socket's SID + * @skb_sid: the packet's SID + * @conn_sid: the resulting connection SID + * + * If @skb_sid is valid then the user:role:type information from @sk_sid is + * combined with the MLS information from @skb_sid in order to create + * @conn_sid. If @skb_sid is not valid then then @conn_sid is simply a copy + * of @sk_sid. Returns zero on success, negative values on failure. + * + */ +static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid) +{ + int err = 0; + + if (skb_sid != SECSID_NULL) + err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid); + else + *conn_sid = sk_sid; + + return err; +} + /* socket security operations */ static int socket_sockcreate_sid(const struct task_security_struct *tsec, @@ -4355,7 +4379,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct sk_security_struct *sksec = sk->sk_security; int err; u16 family = sk->sk_family; - u32 newsid; + u32 connsid; u32 peersid; /* handle mapped IPv4 packets arriving via IPv6 sockets */ @@ -4365,16 +4389,11 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, err = selinux_skb_peerlbl_sid(skb, family, &peersid); if (err) return err; - if (peersid == SECSID_NULL) { - req->secid = sksec->sid; - req->peer_secid = SECSID_NULL; - } else { - err = security_sid_mls_copy(sksec->sid, peersid, &newsid); - if (err) - return err; - req->secid = newsid; - req->peer_secid = peersid; - } + err = selinux_conn_sid(sksec->sid, peersid, &connsid); + if (err) + return err; + req->secid = connsid; + req->peer_secid = peersid; return selinux_netlbl_inet_conn_request(req, family); } @@ -4723,12 +4742,12 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, if (!secmark_active && !peerlbl_active) return NF_ACCEPT; - /* if the packet is being forwarded then get the peer label from the - * packet itself; otherwise check to see if it is from a local - * application or the kernel, if from an application get the peer label - * from the sending socket, otherwise use the kernel's sid */ sk = skb->sk; if (sk == NULL) { + /* Without an associated socket the packet is either coming + * from the kernel or it is being forwarded; check the packet + * to determine which and if the packet is being forwarded + * query the packet directly to determine the security label. */ if (skb->skb_iif) { secmark_perm = PACKET__FORWARD_OUT; if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) @@ -4737,7 +4756,26 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, secmark_perm = PACKET__SEND; peer_sid = SECINITSID_KERNEL; } + } else if (sk->sk_state == TCP_LISTEN) { + /* Locally generated packet but the associated socket is in the + * listening state which means this is a SYN-ACK packet. In + * this particular case the correct security label is assigned + * to the connection/request_sock but unfortunately we can't + * query the request_sock as it isn't queued on the parent + * socket until after the SYN-ACK packet is sent; the only + * viable choice is to regenerate the label like we do in + * selinux_inet_conn_request(). See also selinux_ip_output() + * for similar problems. */ + u32 skb_sid; + struct sk_security_struct *sksec = sk->sk_security; + if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) + return NF_DROP; + if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) + return NF_DROP; + secmark_perm = PACKET__SEND; } else { + /* Locally generated packet, fetch the security label from the + * associated socket. */ struct sk_security_struct *sksec = sk->sk_security; peer_sid = sksec->sid; secmark_perm = PACKET__SEND; |