SELinux: use SECINITSID_NETMSG instead of SECINITSID_UNLABELED for NetLabel
PATCH 1/1 SELinux: use SECINITSID_NETMSG instead of SECINITSID_UNLABELED for NetLabel
These changes will make NetLabel behave like labeled IPsec where there is an access check for both labeled and unlabeled packets as well as providing the ability to restrict domains to receiving only labeled packets when NetLabel is in use. The changes to the policy are straight forward with the following necessary to receive labeled traffic (with SECINITSID_NETMSG defined as "netlabel_peer_t"):
allow mydom_t netlabel_peer_t:{ tcp_socket udp_socket rawip_socket } recvfrom;
The policy for unlabeled traffic would be:
allow mydom_t unlabeled_t:{ tcp_socket udp_socket rawip_socket } recvfrom;
These policy changes, as well as more general NetLabel support, are included in the SELinux Reference Policy SVN tree, r2352 or later. Users who enable NetLabel support in the kernel are strongly encouraged to upgrade their policy to avoid network problems.
--- security/selinux/hooks.c | 21 +++++++++++---------- security/selinux/netlabel.c | 34 +++++++++++++--------------------- 2 files changed, 24 insertions(+), 31 deletions(-)
security/selinux/hooks.c +11 -10
@@ -3124,17 +3124,19 @@ static int selinux_parse_skb(struct sk_b/** * selinux_skb_extlbl_sid - Determine the external label of a packet * @skb: the packet -* @base_sid: the SELinux SID to use as a context for MLS only external labels * @sid: the packet's SID * * Description: * Check the various different forms of external packet labeling and determine -* the external SID for the packet. +* the external SID for the packet. If only one form of external labeling is +* present then it is used, if both labeled IPsec and NetLabel labels are +* present then the SELinux type information is taken from the labeled IPsec +* SA and the MLS sensitivity label information is taken from the NetLabel +* security attributes. This bit of "magic" is done in the call to +* selinux_netlbl_skbuff_getsid(). * */ -static void selinux_skb_extlbl_sid (struct sk_buff *skb, -u32 base_sid, -u32 *sid) +static void selinux_skb_extlbl_sid (struct sk_buff *skb,u32 *sid) {u32 xfrm_sid;u32 nlbl_sid;
@@ -3142,10 +3144,9 @@ static void selinux_skb_extlbl_sid(strucselinux_skb_xfrm_sid (skb, &xfrm_sid);if (selinux_netlbl_skbuff_getsid (skb, (xfrm_sid ==SECSID_NULL ? - base_sid : xfrm_sid), +SECINITSID_NETMSG : xfrm_sid), &nlbl_sid) !=0 ) nlbl_sid =SECSID_NULL ; - *sid = (nlbl_sid ==SECSID_NULL ? xfrm_sid : nlbl_sid); }
@@ -3690,7 +3691,7 @@ static int selinux_socket_getpeersec_dgrif (sock && sock->sk->sk_family ==PF_UNIX )selinux_get_inode_sid (SOCK_INODE (sock), &peer_secid);else if (skb) -selinux_skb_extlbl_sid (skb,SECINITSID_UNLABELED , &peer_secid); +selinux_skb_extlbl_sid (skb, &peer_secid);if (peer_secid ==SECSID_NULL ) err = -EINVAL ;
@@ -3751,7 +3752,7 @@ static int selinux_inet_conn_request(stru32 newsid;u32 peersid; -selinux_skb_extlbl_sid (skb,SECINITSID_UNLABELED , &peersid); +selinux_skb_extlbl_sid (skb, &peersid);if (peersid ==SECSID_NULL ) { req->secid = sksec->sid; req->peer_secid =SECSID_NULL ;
@@ -3789,7 +3790,7 @@ static void selinux_inet_conn_establishe {struct sk_security_struct *sksec = sk->sk_security; -selinux_skb_extlbl_sid (skb,SECINITSID_UNLABELED , &sksec->peer_sid); +selinux_skb_extlbl_sid (skb, &sksec->peer_sid); } static void selinux_req_classify_flow(const struct request_sock *req,
security/selinux/netlabel.c +13 -21
@@ -158,9 +158,7 @@ int selinux_netlbl_skbuff_getsid(structnetlbl_secattr_init (&secattr); rc =netlbl_skbuff_getattr (skb, &secattr);if (rc ==0 && secattr.flags !=NETLBL_SECATTR_NONE ) - rc =security_netlbl_secattr_to_sid (&secattr, - base_sid, - sid); + rc =security_netlbl_secattr_to_sid (&secattr, base_sid, sid);else *sid =SECSID_NULL ;netlbl_secattr_destroy (&secattr);
@@ -198,7 +196,7 @@ void selinux_netlbl_sock_graft(struct soif (netlbl_sock_getattr (sk, &secattr) ==0 && secattr.flags !=NETLBL_SECATTR_NONE &&security_netlbl_secattr_to_sid (&secattr, -SECINITSID_UNLABELED , +SECINITSID_NETMSG , &nlbl_peer_sid) ==0 ) sksec->peer_sid = nlbl_peer_sid;netlbl_secattr_destroy (&secattr);
@@ -295,38 +293,32 @@ int selinux_netlbl_sock_rcv_skb(struct s struct avc_audit_data *ad) {int rc; -u32 netlbl_sid; -u32 recv_perm; +u32 nlbl_sid; +u32 perm; - rc =selinux_netlbl_skbuff_getsid (skb, -SECINITSID_UNLABELED , - &netlbl_sid); + rc =selinux_netlbl_skbuff_getsid (skb,SECINITSID_NETMSG , &nlbl_sid);if (rc !=0 )return rc; - -if (netlbl_sid ==SECSID_NULL ) -return 0 ; +if (nlbl_sid ==SECSID_NULL ) + nlbl_sid =SECINITSID_UNLABELED ;switch (sksec->sclass) {case SECCLASS_UDP_SOCKET : - recv_perm =UDP_SOCKET__RECVFROM ; + perm =UDP_SOCKET__RECVFROM ;break ;case SECCLASS_TCP_SOCKET : - recv_perm =TCP_SOCKET__RECVFROM ; + perm =TCP_SOCKET__RECVFROM ;break ;default : - recv_perm =RAWIP_SOCKET__RECVFROM ; + perm =RAWIP_SOCKET__RECVFROM ; } - rc =avc_has_perm (sksec->sid, - netlbl_sid, - sksec->sclass, - recv_perm, - ad); + rc =avc_has_perm (sksec->sid, nlbl_sid, sksec->sclass, perm, ad);if (rc ==0 )return 0 ; -netlbl_skbuff_err (skb, rc); +if (nlbl_sid !=SECINITSID_UNLABELED ) +netlbl_skbuff_err (skb, rc);return rc; }
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paul moore linux security @ hp -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to [email protected] with the words "unsubscribe selinux" without quotes as the message.
Quoted 6 lines · Paul Moore
These changes will make NetLabel behave like labeled IPsec where there is an access check for both labeled and unlabeled packets as well as providing the ability to restrict domains to receiving only labeled packets when NetLabel is in use. The changes to the policy are straight forward with the following necessary to receive labeled traffic (with
SECINITSID_NETMSGdefined as "netlabel_peer_t"):
Applied togit://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm
Please test, as the next mainline merge window could open at any time.
Signature · 7 lines
James Morris <[email protected]> -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to [email protected] with the words "unsubscribe selinux" without quotes as the message.
Quoted 11 lines · James Morris
Quoted 6 lines · Paul Moore
These changes will make NetLabel behave like labeled IPsec where there is an access check for both labeled and unlabeled packets as well as providing the ability to restrict domains to receiving only labeled packets when NetLabel is in use. The changes to the policy are straight forward with the following necessary to receive labeled traffic (with
SECINITSID_NETMSGdefined as "netlabel_peer_t"):Applied to
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-a
kpm
Thanks.
Quoted 1 line
Please test, as the next mainline merge window could open at any time.
I have been testing this with the associated policy changes for a little while now and have not seen any regressions. I haven't yet had a chance to verify the new Reference Policy release that Chris just announced but I plan to at least boot it once before the end of the day.
Signature · 7 lines
paul moore linux security @ hp -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to [email protected] with the words "unsubscribe selinux" without quotes as the message.