Currently when an IPSec policy rule doesn't specify a security context, it is assumed to be "unlabeled" by SELinux, and so the IPSec policy rule fails to match to a flow that it would otherwise match to, unless one has explicitly added an SELinux policy rule allowing the flow to "polmatch" to the "unlabeled" IPSec policy rules. In the absence of such an explicitly added SELinux policy rule, the IPSec policy rule fails to match and so the packet(s) flow in clear text without the otherwise applicable xfrm(s) applied. The above SELinux behavior violates the SELinux security notion of "deny by default" which should actually translate to "encrypt by default" in the above case. This was first reported by Evgeniy Polyakov and the way James Morris was seeing the problem was when connecting via IPsec to a confined service on an SELinux box (vsftpd), which did not have the appropriate SELinux policy permissions to send packets via IPsec. With this patch applied, SELinux "polmatching" of flows Vs. IPSec policy rules will only come into play when there's a explicit context specified for the IPSec policy rule (which also means there's corresponding SELinux policy allowing appropriate domains/flows to polmatch to this context). Secondly, when a security module is loaded (in this case, SELinux), the security_xfrm_policy_lookup() hook can return errors other than access denied, such as -EINVAL. We were not handling that correctly, and in fact inverting the return logic and propagating a false "ok" back up to xfrm_lookup(), which then allowed packets to pass as if they were not associated with an xfrm policy. The solution for this is to first ensure that errno values are correctly propagated all the way back up through the various call chains from security_xfrm_policy_lookup(), and handled correctly. Then, flow_cache_lookup() is modified, so that if the policy resolver fails (typically a permission denied via the security module), the flow cache entry is killed rather than having a null policy assigned (which indicates that the packet can pass freely). This also forces any future lookups for the same flow to consult the security module (e.g. SELinux) for current security policy (rather than, say, caching the error on the flow cache entry). This patch: Fix the selinux side of things. This makes sure SELinux polmatching of flow contexts to IPSec policy rules comes into play only when an explicit context is associated with the IPSec policy rule. Also, this no longer defaults the context of a socket policy to the context of the socket since the "no explicit context" case is now handled properly. Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: James Morris <jmorris@namei.org>
[assuming BSD security levels are deleted] The only user of i_security, f_security, s_security fields is SELinux, however, quite a few security modules are trying to get into kernel. So, wrap them under CONFIG_SECURITY. Adding config option for each security field is likely an overkill. Following Stephen Smalley's suggestion, i_security initialization is moved to security_inode_alloc() to not clutter core code with ifdefs and make alloc_inode() codepath tiny little bit smaller and faster. The user of (highly greppable) struct fown_struct::security field is still to be found. I've checked every "fown_struct" and every "f_owner" occurence. Additionally it's removal doesn't break i386 allmodconfig build. struct inode, struct file, struct super_block, struct fown_struct become smaller. P.S. Combined with two reiserfs inode shrinking patches sent to linux-fsdevel, I can finally suck 12 reiserfs inodes into one page. /proc/slabinfo -ext2_inode_cache 388 10 +ext2_inode_cache 384 10 -inode_cache 280 14 +inode_cache 276 14 -proc_inode_cache 296 13 +proc_inode_cache 292 13 -reiser_inode_cache 336 11 +reiser_inode_cache 332 12 <= -shmem_inode_cache 372 10 +shmem_inode_cache 368 10 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add NetLabel support to the SELinux LSM and modify the socket_post_create() LSM hook to return an error code. The most significant part of this patch is the addition of NetLabel hooks into the following SELinux LSM hooks: * selinux_file_permission() * selinux_socket_sendmsg() * selinux_socket_post_create() * selinux_socket_sock_rcv_skb() * selinux_socket_getpeersec_stream() * selinux_socket_getpeersec_dgram() * selinux_sock_graft() * selinux_inet_conn_request() The basic reasoning behind this patch is that outgoing packets are "NetLabel'd" by labeling their socket and the NetLabel security attributes are checked via the additional hook in selinux_socket_sock_rcv_skb(). NetLabel itself is only a labeling mechanism, similar to filesystem extended attributes, it is up to the SELinux enforcement mechanism to perform the actual access checks. In addition to the changes outlined above this patch also includes some changes to the extended bitmap (ebitmap) and multi-level security (mls) code to import and export SELinux TE/MLS attributes into and out of NetLabel. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This automatically labels the TCP, Unix stream, and dccp child sockets as well as openreqs to be at the same MLS level as the peer. This will result in the selection of appropriately labeled IPSec Security Associations. This also uses the sock's sid (as opposed to the isec sid) in SELinux enforcement of secmark in rcv_skb and postroute_last hooks. Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This defaults the label of socket-specific IPSec policies to be the same as the socket they are set on. Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This labels the flows that could utilize IPSec xfrms at the points the flows are defined so that IPSec policy and SAs at the right label can be used. The following protos are currently not handled, but they should continue to be able to use single-labeled IPSec like they currently do. ipmr ip_gre ipip igmp sit sctp ip6_tunnel (IPv6 over IPv6 tunnel device) decnet Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This implements a seemless mechanism for xfrm policy selection and state matching based on the flow sid. This also includes the necessary SELinux enforcement pieces. Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This adds security for IP sockets at the sock level. Security at the sock level is needed to enforce the SELinux security policy for security associations even when a sock is orphaned (such as in the TCP LAST_ACK state). This will also be used to enforce SELinux controls over data arriving at or leaving a child socket while it's still waiting to be accepted. Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/security.h: In function ‘security_release_secctx’: include/linux/security.h:2757: warning: ‘return’ with a value, in function returning void Signed-off-by: David S. Miller <davem@davemloft.net>
From: Catherine Zhang <cxzhang@watson.ibm.com> This patch implements a cleaner fix for the memory leak problem of the original unix datagram getpeersec patch. Instead of creating a security context each time a unix datagram is sent, we only create the security context when the receiver requests it. This new design requires modification of the current unix_getsecpeer_dgram LSM hook and addition of two new hooks, namely, secid_to_secctx and release_secctx. The former retrieves the security context and the latter releases it. A hook is required for releasing the security context because it is up to the security module to decide how that's done. In the case of Selinux, it's a simple kfree operation. Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: David S. Miller <davem@davemloft.net>