From aa86290089a1e57b4bdbbb4720072233f66bd5b2 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:29 -0400 Subject: selinux: Correctly handle IPv4 packets on IPv6 sockets in all cases We did the right thing in a few cases but there were several areas where we determined a packet's address family based on the socket's address family which is not the right thing to do since we can get IPv4 packets on IPv6 sockets. This patch fixes these problems by either taking the address family directly from the packet. Signed-off-by: Paul Moore Acked-by: James Morris --- security/selinux/hooks.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 03fc6a81ae3..223f474bee8 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4207,10 +4207,12 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff * u32 peer_secid = SECSID_NULL; u16 family; - if (sock) + if (skb && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + else if (skb && skb->protocol == htons(ETH_P_IPV6)) + family = PF_INET6; + else if (sock) family = sock->sk->sk_family; - else if (skb && skb->sk) - family = skb->sk->sk_family; else goto out; @@ -4277,10 +4279,15 @@ 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 peersid; - err = selinux_skb_peerlbl_sid(skb, sk->sk_family, &peersid); + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + err = selinux_skb_peerlbl_sid(skb, family, &peersid); if (err) return err; if (peersid == SECSID_NULL) { @@ -4318,9 +4325,14 @@ static void selinux_inet_csk_clone(struct sock *newsk, static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) { + u16 family = sk->sk_family; struct sk_security_struct *sksec = sk->sk_security; - selinux_skb_peerlbl_sid(skb, sk->sk_family, &sksec->peer_sid); + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); } static void selinux_req_classify_flow(const struct request_sock *req, -- cgit v1.2.3 From d8395c876bb8a560c8a032887e191b95499a25d6 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:30 -0400 Subject: selinux: Better local/forward check in selinux_ip_postroute() It turns out that checking to see if skb->sk is NULL is not a very good indicator of a forwarded packet as some locally generated packets also have skb->sk set to NULL. Fix this by not only checking the skb->sk field but also the IP[6]CB(skb)->flags field for the IP[6]SKB_FORWARDED flag. While we are at it, we are calling selinux_parse_skb() much earlier than we really should resulting in potentially wasted cycles parsing packets for information we might no use; so shuffle the code around a bit to fix this. Signed-off-by: Paul Moore Acked-by: James Morris --- security/selinux/hooks.c | 126 ++++++++++++++++++++++++++++++----------------- 1 file changed, 81 insertions(+), 45 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 223f474bee8..b520667a24b 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4070,20 +4070,28 @@ static int selinux_sock_rcv_skb_iptables_compat(struct sock *sk, } static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, - struct avc_audit_data *ad, - u16 family, char *addrp) + u16 family) { int err; struct sk_security_struct *sksec = sk->sk_security; u32 peer_sid; u32 sk_sid = sksec->sid; + struct avc_audit_data ad; + char *addrp; + + AVC_AUDIT_DATA_INIT(&ad, NET); + ad.u.net.netif = skb->iif; + ad.u.net.family = family; + err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); + if (err) + return err; if (selinux_compat_net) - err = selinux_sock_rcv_skb_iptables_compat(sk, skb, ad, + err = selinux_sock_rcv_skb_iptables_compat(sk, skb, &ad, family, addrp); else err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, - PACKET__RECV, ad); + PACKET__RECV, &ad); if (err) return err; @@ -4092,12 +4100,12 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, if (err) return err; err = avc_has_perm(sk_sid, peer_sid, - SECCLASS_PEER, PEER__RECV, ad); + SECCLASS_PEER, PEER__RECV, &ad); } else { - err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, ad); + err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); if (err) return err; - err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, ad); + err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); } return err; @@ -4111,6 +4119,8 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) u32 sk_sid = sksec->sid; struct avc_audit_data ad; char *addrp; + u8 secmark_active; + u8 peerlbl_active; if (family != PF_INET && family != PF_INET6) return 0; @@ -4119,6 +4129,18 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) family = PF_INET; + /* If any sort of compatibility mode is enabled then handoff processing + * to the selinux_sock_rcv_skb_compat() function to deal with the + * special handling. We do this in an attempt to keep this function + * as fast and as clean as possible. */ + if (selinux_compat_net || !selinux_policycap_netpeer) + return selinux_sock_rcv_skb_compat(sk, skb, family); + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); + if (!secmark_active && !peerlbl_active) + return 0; + AVC_AUDIT_DATA_INIT(&ad, NET); ad.u.net.netif = skb->iif; ad.u.net.family = family; @@ -4126,15 +4148,7 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) if (err) return err; - /* If any sort of compatibility mode is enabled then handoff processing - * to the selinux_sock_rcv_skb_compat() function to deal with the - * special handling. We do this in an attempt to keep this function - * as fast and as clean as possible. */ - if (selinux_compat_net || !selinux_policycap_netpeer) - return selinux_sock_rcv_skb_compat(sk, skb, &ad, - family, addrp); - - if (netlbl_enabled() || selinux_xfrm_enabled()) { + if (peerlbl_active) { u32 peer_sid; err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); @@ -4148,7 +4162,7 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) PEER__RECV, &ad); } - if (selinux_secmark_enabled()) { + if (secmark_active) { err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, PACKET__RECV, &ad); if (err) @@ -4396,15 +4410,15 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, if (!secmark_active && !peerlbl_active) return NF_ACCEPT; + if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) + return NF_DROP; + AVC_AUDIT_DATA_INIT(&ad, NET); ad.u.net.netif = ifindex; ad.u.net.family = family; if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) return NF_DROP; - if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) - return NF_DROP; - if (peerlbl_active) if (selinux_inet_sys_rcv_skb(ifindex, addrp, family, peer_sid, &ad) != 0) @@ -4505,30 +4519,36 @@ static int selinux_ip_postroute_iptables_compat(struct sock *sk, static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, int ifindex, - struct avc_audit_data *ad, - u16 family, - char *addrp, - u8 proto) + u16 family) { struct sock *sk = skb->sk; struct sk_security_struct *sksec; + struct avc_audit_data ad; + char *addrp; + u8 proto; if (sk == NULL) return NF_ACCEPT; sksec = sk->sk_security; + AVC_AUDIT_DATA_INIT(&ad, NET); + ad.u.net.netif = ifindex; + ad.u.net.family = family; + if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) + return NF_DROP; + if (selinux_compat_net) { if (selinux_ip_postroute_iptables_compat(skb->sk, ifindex, - ad, family, addrp)) + &ad, family, addrp)) return NF_DROP; } else { if (avc_has_perm(sksec->sid, skb->secmark, - SECCLASS_PACKET, PACKET__SEND, ad)) + SECCLASS_PACKET, PACKET__SEND, &ad)) return NF_DROP; } if (selinux_policycap_netpeer) - if (selinux_xfrm_postroute_last(sksec->sid, skb, ad, proto)) + if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) return NF_DROP; return NF_ACCEPT; @@ -4542,23 +4562,15 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, struct sock *sk; struct avc_audit_data ad; char *addrp; - u8 proto; u8 secmark_active; u8 peerlbl_active; - AVC_AUDIT_DATA_INIT(&ad, NET); - ad.u.net.netif = ifindex; - ad.u.net.family = family; - if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) - return NF_DROP; - /* If any sort of compatibility mode is enabled then handoff processing * to the selinux_ip_postroute_compat() function to deal with the * special handling. We do this in an attempt to keep this function * as fast and as clean as possible. */ if (selinux_compat_net || !selinux_policycap_netpeer) - return selinux_ip_postroute_compat(skb, ifindex, &ad, - family, addrp, proto); + return selinux_ip_postroute_compat(skb, ifindex, family); /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec * packet transformation so allow the packet to pass without any checks @@ -4574,21 +4586,45 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, if (!secmark_active && !peerlbl_active) return NF_ACCEPT; - /* if the packet is locally generated (skb->sk != NULL) then use the - * socket's label as the peer label, otherwise the packet is being - * forwarded through this system and we need to fetch the peer label - * directly from the packet */ + /* 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) { + if (sk == NULL) { + switch (family) { + case PF_INET: + if (IPCB(skb)->flags & IPSKB_FORWARDED) + secmark_perm = PACKET__FORWARD_OUT; + else + secmark_perm = PACKET__SEND; + break; + case PF_INET6: + if (IP6CB(skb)->flags & IP6SKB_FORWARDED) + secmark_perm = PACKET__FORWARD_OUT; + else + secmark_perm = PACKET__SEND; + break; + default: + return NF_DROP; + } + if (secmark_perm == PACKET__FORWARD_OUT) { + if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) + return NF_DROP; + } else + peer_sid = SECINITSID_KERNEL; + } else { struct sk_security_struct *sksec = sk->sk_security; peer_sid = sksec->sid; secmark_perm = PACKET__SEND; - } else { - if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) - return NF_DROP; - secmark_perm = PACKET__FORWARD_OUT; } + AVC_AUDIT_DATA_INIT(&ad, NET); + ad.u.net.netif = ifindex; + ad.u.net.family = family; + if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) + return NF_DROP; + if (secmark_active) if (avc_has_perm(peer_sid, skb->secmark, SECCLASS_PACKET, secmark_perm, &ad)) -- cgit v1.2.3 From dfaebe9825ff34983778f287101bc5f3bce00640 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:31 -0400 Subject: selinux: Fix missing calls to netlbl_skbuff_err() At some point I think I messed up and dropped the calls to netlbl_skbuff_err() which are necessary for CIPSO to send error notifications to remote systems. This patch re-introduces the error handling calls into the SELinux code. Signed-off-by: Paul Moore Acked-by: James Morris --- security/selinux/hooks.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b520667a24b..a91146a6b37 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4101,6 +4101,8 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, return err; err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, PEER__RECV, &ad); + if (err) + selinux_netlbl_err(skb, err, 0); } else { err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); if (err) @@ -4156,10 +4158,14 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) return err; err = selinux_inet_sys_rcv_skb(skb->iif, addrp, family, peer_sid, &ad); - if (err) + if (err) { + selinux_netlbl_err(skb, err, 0); return err; + } err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, PEER__RECV, &ad); + if (err) + selinux_netlbl_err(skb, err, 0); } if (secmark_active) { @@ -4396,6 +4402,7 @@ out: static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, u16 family) { + int err; char *addrp; u32 peer_sid; struct avc_audit_data ad; @@ -4419,10 +4426,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) return NF_DROP; - if (peerlbl_active) - if (selinux_inet_sys_rcv_skb(ifindex, addrp, family, - peer_sid, &ad) != 0) + if (peerlbl_active) { + err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, + peer_sid, &ad); + if (err) { + selinux_netlbl_err(skb, err, 1); return NF_DROP; + } + } if (secmark_active) if (avc_has_perm(peer_sid, skb->secmark, -- cgit v1.2.3 From 948bf85c1bc9a84754786a9d5dd99b7ecc46451e Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:32 -0400 Subject: netlabel: Add functionality to set the security attributes of a packet This patch builds upon the new NetLabel address selector functionality by providing the NetLabel KAPI and CIPSO engine support needed to enable the new packet-based labeling. The only new addition to the NetLabel KAPI at this point is shown below: * int netlbl_skbuff_setattr(skb, family, secattr) ... and is designed to be called from a Netfilter hook after the packet's IP header has been populated such as in the FORWARD or LOCAL_OUT hooks. This patch also provides the necessary SELinux hooks to support this new functionality. Smack support is not currently included due to uncertainty regarding the permissions needed to expand the Smack network access controls. Signed-off-by: Paul Moore Reviewed-by: James Morris --- security/selinux/hooks.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a91146a6b37..7432bdd5d36 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4407,13 +4407,15 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, u32 peer_sid; struct avc_audit_data ad; u8 secmark_active; + u8 netlbl_active; u8 peerlbl_active; if (!selinux_policycap_netpeer) return NF_ACCEPT; secmark_active = selinux_secmark_enabled(); - peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); + netlbl_active = netlbl_enabled(); + peerlbl_active = netlbl_active || selinux_xfrm_enabled(); if (!secmark_active && !peerlbl_active) return NF_ACCEPT; @@ -4440,6 +4442,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) return NF_DROP; + if (netlbl_active) + /* we do this in the FORWARD path and not the POST_ROUTING + * path because we want to make sure we apply the necessary + * labeling before IPsec is applied so we can leverage AH + * protection */ + if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) + return NF_DROP; + return NF_ACCEPT; } @@ -4463,6 +4473,37 @@ static unsigned int selinux_ipv6_forward(unsigned int hooknum, } #endif /* IPV6 */ +static unsigned int selinux_ip_output(struct sk_buff *skb, + u16 family) +{ + u32 sid; + + if (!netlbl_enabled()) + return NF_ACCEPT; + + /* we do this in the LOCAL_OUT path and not the POST_ROUTING path + * because we want to make sure we apply the necessary labeling + * before IPsec is applied so we can leverage AH protection */ + if (skb->sk) { + struct sk_security_struct *sksec = skb->sk->sk_security; + sid = sksec->sid; + } else + sid = SECINITSID_KERNEL; + if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) + return NF_DROP; + + return NF_ACCEPT; +} + +static unsigned int selinux_ipv4_output(unsigned int hooknum, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return selinux_ip_output(skb, PF_INET); +} + static int selinux_ip_postroute_iptables_compat(struct sock *sk, int ifindex, struct avc_audit_data *ad, @@ -5700,6 +5741,13 @@ static struct nf_hook_ops selinux_ipv4_ops[] = { .pf = PF_INET, .hooknum = NF_INET_FORWARD, .priority = NF_IP_PRI_SELINUX_FIRST, + }, + { + .hook = selinux_ipv4_output, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_SELINUX_FIRST, } }; -- cgit v1.2.3 From 014ab19a69c325f52d7bae54ceeda73d6307ae0c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:33 -0400 Subject: selinux: Set socket NetLabel based on connection endpoint Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to solve that by applying NetLabel socket labels when sockets are connect()'d. This should alleviate the per-packet NetLabel labeling for all connected sockets (yes, it even works for connected DGRAM sockets). Signed-off-by: Paul Moore Reviewed-by: James Morris --- security/selinux/hooks.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 7432bdd5d36..632ac3e80a6 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3794,6 +3794,7 @@ out: static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) { + struct sock *sk = sock->sk; struct inode_security_struct *isec; int err; @@ -3807,7 +3808,6 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, isec = SOCK_INODE(sock)->i_security; if (isec->sclass == SECCLASS_TCP_SOCKET || isec->sclass == SECCLASS_DCCP_SOCKET) { - struct sock *sk = sock->sk; struct avc_audit_data ad; struct sockaddr_in *addr4 = NULL; struct sockaddr_in6 *addr6 = NULL; @@ -3841,6 +3841,8 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, goto out; } + err = selinux_netlbl_socket_connect(sk, address); + out: return err; } @@ -4290,8 +4292,6 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent) sk->sk_family == PF_UNIX) isec->sid = sksec->sid; sksec->sclass = isec->sclass; - - selinux_netlbl_sock_graft(sk, parent); } static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, @@ -4342,8 +4342,7 @@ static void selinux_inet_csk_clone(struct sock *newsk, selinux_netlbl_sk_security_reset(newsksec, req->rsk_ops->family); } -static void selinux_inet_conn_established(struct sock *sk, - struct sk_buff *skb) +static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) { u16 family = sk->sk_family; struct sk_security_struct *sksec = sk->sk_security; @@ -4353,6 +4352,8 @@ static void selinux_inet_conn_established(struct sock *sk, family = PF_INET; selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); + + selinux_netlbl_inet_conn_established(sk, family); } static void selinux_req_classify_flow(const struct request_sock *req, -- cgit v1.2.3 From 6c5b3fc0147f79d714d2fe748b5869d7892ef2e7 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:33 -0400 Subject: selinux: Cache NetLabel secattrs in the socket's security struct Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to mitigate some of that overhead by caching the NetLabel security attribute struct within the SELinux socket security structure. This should help eliminate the need to recreate the NetLabel secattr structure for each packet resulting in less overhead. Signed-off-by: Paul Moore Acked-by: James Morris --- security/selinux/hooks.c | 1 + 1 file changed, 1 insertion(+) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 632ac3e80a6..3aa811eba25 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -291,6 +291,7 @@ static void sk_free_security(struct sock *sk) struct sk_security_struct *ssec = sk->sk_security; sk->sk_security = NULL; + selinux_netlbl_sk_security_free(ssec); kfree(ssec); } -- cgit v1.2.3