1. 19 10月, 2007 1 次提交
    • A
      V3 file capabilities: alter behavior of cap_setpcap · 72c2d582
      Andrew Morgan 提交于
      The non-filesystem capability meaning of CAP_SETPCAP is that a process, p1,
      can change the capabilities of another process, p2.  This is not the
      meaning that was intended for this capability at all, and this
      implementation came about purely because, without filesystem capabilities,
      there was no way to use capabilities without one process bestowing them on
      another.
      
      Since we now have a filesystem support for capabilities we can fix the
      implementation of CAP_SETPCAP.
      
      The most significant thing about this change is that, with it in effect, no
      process can set the capabilities of another process.
      
      The capabilities of a program are set via the capability convolution
      rules:
      
         pI(post-exec) = pI(pre-exec)
         pP(post-exec) = (X(aka cap_bset) & fP) | (pI(post-exec) & fI)
         pE(post-exec) = fE ? pP(post-exec) : 0
      
      at exec() time.  As such, the only influence the pre-exec() program can
      have on the post-exec() program's capabilities are through the pI
      capability set.
      
      The correct implementation for CAP_SETPCAP (and that enabled by this patch)
      is that it can be used to add extra pI capabilities to the current process
      - to be picked up by subsequent exec()s when the above convolution rules
      are applied.
      
      Here is how it works:
      
      Let's say we have a process, p. It has capability sets, pE, pP and pI.
      Generally, p, can change the value of its own pI to pI' where
      
         (pI' & ~pI) & ~pP = 0.
      
      That is, the only new things in pI' that were not present in pI need to
      be present in pP.
      
      The role of CAP_SETPCAP is basically to permit changes to pI beyond
      the above:
      
         if (pE & CAP_SETPCAP) {
            pI' = anything; /* ie., even (pI' & ~pI) & ~pP != 0  */
         }
      
      This capability is useful for things like login, which (say, via
      pam_cap) might want to raise certain inheritable capabilities for use
      by the children of the logged-in user's shell, but those capabilities
      are not useful to or needed by the login program itself.
      
      One such use might be to limit who can run ping. You set the
      capabilities of the 'ping' program to be "= cap_net_raw+i", and then
      only shells that have (pI & CAP_NET_RAW) will be able to run
      it. Without CAP_SETPCAP implemented as described above, login(pam_cap)
      would have to also have (pP & CAP_NET_RAW) in order to raise this
      capability and pass it on through the inheritable set.
      Signed-off-by: NAndrew Morgan <morgan@kernel.org>
      Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
      Cc: Stephen Smalley <sds@tycho.nsa.gov>
      Cc: James Morris <jmorris@namei.org>
      Cc: Casey Schaufler <casey@schaufler-ca.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      72c2d582
  2. 17 10月, 2007 4 次提交
    • A
      security/ cleanups · cbfee345
      Adrian Bunk 提交于
      This patch contains the following cleanups that are now possible:
      - remove the unused security_operations->inode_xattr_getsuffix
      - remove the no longer used security_operations->unregister_security
      - remove some no longer required exit code
      - remove a bunch of no longer used exports
      Signed-off-by: NAdrian Bunk <bunk@kernel.org>
      Acked-by: NJames Morris <jmorris@namei.org>
      Cc: Chris Wright <chrisw@sous-sol.org>
      Cc: Stephen Smalley <sds@tycho.nsa.gov>
      Cc: Serge Hallyn <serue@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cbfee345
    • S
      Implement file posix capabilities · b5376771
      Serge E. Hallyn 提交于
      Implement file posix capabilities.  This allows programs to be given a
      subset of root's powers regardless of who runs them, without having to use
      setuid and giving the binary all of root's powers.
      
      This version works with Kaigai Kohei's userspace tools, found at
      http://www.kaigai.gr.jp/index.php.  For more information on how to use this
      patch, Chris Friedhoff has posted a nice page at
      http://www.friedhoff.org/fscaps.html.
      
      Changelog:
      	Nov 27:
      	Incorporate fixes from Andrew Morton
      	(security-introduce-file-caps-tweaks and
      	security-introduce-file-caps-warning-fix)
      	Fix Kconfig dependency.
      	Fix change signaling behavior when file caps are not compiled in.
      
      	Nov 13:
      	Integrate comments from Alexey: Remove CONFIG_ ifdef from
      	capability.h, and use %zd for printing a size_t.
      
      	Nov 13:
      	Fix endianness warnings by sparse as suggested by Alexey
      	Dobriyan.
      
      	Nov 09:
      	Address warnings of unused variables at cap_bprm_set_security
      	when file capabilities are disabled, and simultaneously clean
      	up the code a little, by pulling the new code into a helper
      	function.
      
      	Nov 08:
      	For pointers to required userspace tools and how to use
      	them, see http://www.friedhoff.org/fscaps.html.
      
      	Nov 07:
      	Fix the calculation of the highest bit checked in
      	check_cap_sanity().
      
      	Nov 07:
      	Allow file caps to be enabled without CONFIG_SECURITY, since
      	capabilities are the default.
      	Hook cap_task_setscheduler when !CONFIG_SECURITY.
      	Move capable(TASK_KILL) to end of cap_task_kill to reduce
      	audit messages.
      
      	Nov 05:
      	Add secondary calls in selinux/hooks.c to task_setioprio and
      	task_setscheduler so that selinux and capabilities with file
      	cap support can be stacked.
      
      	Sep 05:
      	As Seth Arnold points out, uid checks are out of place
      	for capability code.
      
      	Sep 01:
      	Define task_setscheduler, task_setioprio, cap_task_kill, and
      	task_setnice to make sure a user cannot affect a process in which
      	they called a program with some fscaps.
      
      	One remaining question is the note under task_setscheduler: are we
      	ok with CAP_SYS_NICE being sufficient to confine a process to a
      	cpuset?
      
      	It is a semantic change, as without fsccaps, attach_task doesn't
      	allow CAP_SYS_NICE to override the uid equivalence check.  But since
      	it uses security_task_setscheduler, which elsewhere is used where
      	CAP_SYS_NICE can be used to override the uid equivalence check,
      	fixing it might be tough.
      
      	     task_setscheduler
      		 note: this also controls cpuset:attach_task.  Are we ok with
      		     CAP_SYS_NICE being used to confine to a cpuset?
      	     task_setioprio
      	     task_setnice
      		 sys_setpriority uses this (through set_one_prio) for another
      		 process.  Need same checks as setrlimit
      
      	Aug 21:
      	Updated secureexec implementation to reflect the fact that
      	euid and uid might be the same and nonzero, but the process
      	might still have elevated caps.
      
      	Aug 15:
      	Handle endianness of xattrs.
      	Enforce capability version match between kernel and disk.
      	Enforce that no bits beyond the known max capability are
      	set, else return -EPERM.
      	With this extra processing, it may be worth reconsidering
      	doing all the work at bprm_set_security rather than
      	d_instantiate.
      
      	Aug 10:
      	Always call getxattr at bprm_set_security, rather than
      	caching it at d_instantiate.
      
      [morgan@kernel.org: file-caps clean up for linux/capability.h]
      [bunk@kernel.org: unexport cap_inode_killpriv]
      Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
      Cc: Stephen Smalley <sds@tycho.nsa.gov>
      Cc: James Morris <jmorris@namei.org>
      Cc: Chris Wright <chrisw@sous-sol.org>
      Cc: Andrew Morgan <morgan@kernel.org>
      Signed-off-by: NAndrew Morgan <morgan@kernel.org>
      Signed-off-by: NAdrian Bunk <bunk@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b5376771
    • J
      security: Convert LSM into a static interface · 20510f2f
      James Morris 提交于
      Convert LSM into a static interface, as the ability to unload a security
      module is not required by in-tree users and potentially complicates the
      overall security architecture.
      
      Needlessly exported LSM symbols have been unexported, to help reduce API
      abuse.
      
      Parameters for the capability and root_plug modules are now specified
      at boot.
      
      The SECURITY_FRAMEWORK_VERSION macro has also been removed.
      
      In a nutshell, there is no safe way to unload an LSM.  The modular interface
      is thus unecessary and broken infrastructure.  It is used only by out-of-tree
      modules, which are often binary-only, illegal, abusive of the API and
      dangerous, e.g.  silently re-vectoring SELinux.
      
      [akpm@linux-foundation.org: cleanups]
      [akpm@linux-foundation.org: USB Kconfig fix]
      [randy.dunlap@oracle.com: fix LSM kernel-doc]
      Signed-off-by: NJames Morris <jmorris@namei.org>
      Acked-by: NChris Wright <chrisw@sous-sol.org>
      Cc: Stephen Smalley <sds@tycho.nsa.gov>
      Cc: "Serge E. Hallyn" <serue@us.ibm.com>
      Acked-by: NArjan van de Ven <arjan@infradead.org>
      Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      20510f2f
    • Y
      SELinux: Improve read/write performance · 788e7dd4
      Yuichi Nakamura 提交于
      It reduces the selinux overhead on read/write by only revalidating
      permissions in selinux_file_permission if the task or inode labels have
      changed or the policy has changed since the open-time check.  A new LSM
      hook, security_dentry_open, is added to capture the necessary state at open
      time to allow this optimization.
      
      (see http://marc.info/?l=selinux&m=118972995207740&w=2)
      
      Signed-off-by: Yuichi Nakamura<ynakam@hitachisoft.jp>
      Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      788e7dd4
  3. 23 8月, 2007 1 次提交
    • A
      fix NULL pointer dereference in __vm_enough_memory() · 34b4e4aa
      Alan Cox 提交于
      The new exec code inserts an accounted vma into an mm struct which is not
      current->mm.  The existing memory check code has a hard coded assumption
      that this does not happen as does the security code.
      
      As the correct mm is known we pass the mm to the security method and the
      helper function.  A new security test is added for the case where we need
      to pass the mm and the existing one is modified to pass current->mm to
      avoid the need to change large amounts of code.
      
      (Thanks to Tobias for fixing rejects and testing)
      Signed-off-by: NAlan Cox <alan@redhat.com>
      Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
      Cc: James Morris <jmorris@redhat.com>
      Cc: Tobias Diedrich <ranma+kernel@tdiedrich.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      34b4e4aa
  4. 20 7月, 2007 1 次提交
  5. 12 7月, 2007 1 次提交
    • E
      security: Protection for exploiting null dereference using mmap · ed032189
      Eric Paris 提交于
      Add a new security check on mmap operations to see if the user is attempting
      to mmap to low area of the address space.  The amount of space protected is
      indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to
      0, preserving existing behavior.
      
      This patch uses a new SELinux security class "memprotect."  Policy already
      contains a number of allow rules like a_t self:process * (unconfined_t being
      one of them) which mean that putting this check in the process class (its
      best current fit) would make it useless as all user processes, which we also
      want to protect against, would be allowed. By taking the memprotect name of
      the new class it will also make it possible for us to move some of the other
      memory protect permissions out of 'process' and into the new class next time
      we bump the policy version number (which I also think is a good future idea)
      Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
      Acked-by: NChris Wright <chrisw@sous-sol.org>
      Signed-off-by: NEric Paris <eparis@redhat.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      ed032189
  6. 15 3月, 2007 1 次提交
  7. 03 12月, 2006 3 次提交
    • V
      SELinux: Fix SA selection semantics · 67f83cbf
      Venkat Yekkirala 提交于
      Fix the selection of an SA for an outgoing packet to be at the same
      context as the originating socket/flow. This eliminates the SELinux
      policy's ability to use/sendto SAs with contexts other than the socket's.
      
      With this patch applied, the SELinux policy will require one or more of the
      following for a socket to be able to communicate with/without SAs:
      
      1. To enable a socket to communicate without using labeled-IPSec SAs:
      
      allow socket_t unlabeled_t:association { sendto recvfrom }
      
      2. To enable a socket to communicate with labeled-IPSec SAs:
      
      allow socket_t self:association { sendto };
      allow socket_t peer_sa_t:association { recvfrom };
      Signed-off-by: NVenkat Yekkirala <vyekkirala@TrustedCS.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      67f83cbf
    • V
      SELinux: Return correct context for SO_PEERSEC · 6b877699
      Venkat Yekkirala 提交于
      Fix SO_PEERSEC for tcp sockets to return the security context of
      the peer (as represented by the SA from the peer) as opposed to the
      SA used by the local/source socket.
      Signed-off-by: NVenkat Yekkirala <vyekkirala@TrustedCS.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      6b877699
    • V
      SELinux: Various xfrm labeling fixes · c1a856c9
      Venkat Yekkirala 提交于
      Since the upstreaming of the mlsxfrm modification a few months back,
      testing has resulted in the identification of the following issues/bugs that
      are resolved in this patch set.
      
      1. Fix the security context used in the IKE negotiation to be the context
         of the socket as opposed to the context of the SPD rule.
      
      2. Fix SO_PEERSEC for tcp sockets to return the security context of
         the peer as opposed to the source.
      
      3. Fix the selection of an SA for an outgoing packet to be at the same
         context as the originating socket/flow.
      
      The following would be the result of applying this patchset:
      
      - SO_PEERSEC will now correctly return the peer's context.
      
      - IKE deamons will receive the context of the source socket/flow
        as opposed to the SPD rule's context so that the negotiated SA
        will be at the same context as the source socket/flow.
      
      - The SELinux policy will require one or more of the
        following for a socket to be able to communicate with/without SAs:
      
        1. To enable a socket to communicate without using labeled-IPSec SAs:
      
           allow socket_t unlabeled_t:association { sendto recvfrom }
      
        2. To enable a socket to communicate with labeled-IPSec SAs:
      
           allow socket_t self:association { sendto };
           allow socket_t peer_sa_t:association { recvfrom };
      
      This Patch: Pass correct security context to IKE for use in negotiation
      
      Fix the security context passed to IKE for use in negotiation to be the
      context of the socket as opposed to the context of the SPD rule so that
      the SA carries the label of the originating socket/flow.
      Signed-off-by: NVenkat Yekkirala <vyekkirala@TrustedCS.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      c1a856c9
  8. 12 10月, 2006 1 次提交
    • V
      IPsec: correct semantics for SELinux policy matching · 5b368e61
      Venkat Yekkirala 提交于
      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: NVenkat Yekkirala <vyekkirala@TrustedCS.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      5b368e61
  9. 23 9月, 2006 6 次提交
  10. 03 8月, 2006 1 次提交
    • C
      [AF_UNIX]: Kernel memory leak fix for af_unix datagram getpeersec patch · dc49c1f9
      Catherine Zhang 提交于
      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: NStephen Smalley <sds@tycho.nsa.gov>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dc49c1f9
  11. 01 7月, 2006 3 次提交
  12. 30 6月, 2006 1 次提交
  13. 27 6月, 2006 1 次提交
  14. 23 6月, 2006 4 次提交
  15. 18 6月, 2006 1 次提交
    • C
      [LSM-IPsec]: SELinux Authorize · c8c05a8e
      Catherine Zhang 提交于
      This patch contains a fix for the previous patch that adds security
      contexts to IPsec policies and security associations.  In the previous
      patch, no authorization (besides the check for write permissions to
      SAD and SPD) is required to delete IPsec policies and security
      assocations with security contexts.  Thus a user authorized to change
      SAD and SPD can bypass the IPsec policy authorization by simply
      deleteing policies with security contexts.  To fix this security hole,
      an additional authorization check is added for removing security
      policies and security associations with security contexts.
      
      Note that if no security context is supplied on add or present on
      policy to be deleted, the SELinux module allows the change
      unconditionally.  The hook is called on deletion when no context is
      present, which we may want to change.  At present, I left it up to the
      module.
      
      LSM changes:
      
      The patch adds two new LSM hooks: xfrm_policy_delete and
      xfrm_state_delete.  The new hooks are necessary to authorize deletion
      of IPsec policies that have security contexts.  The existing hooks
      xfrm_policy_free and xfrm_state_free lack the context to do the
      authorization, so I decided to split authorization of deletion and
      memory management of security data, as is typical in the LSM
      interface.
      
      Use:
      
      The new delete hooks are checked when xfrm_policy or xfrm_state are
      deleted by either the xfrm_user interface (xfrm_get_policy,
      xfrm_del_sa) or the pfkey interface (pfkey_spddelete, pfkey_delete).
      
      SELinux changes:
      
      The new policy_delete and state_delete functions are added.
      Signed-off-by: NCatherine Zhang <cxzhang@watson.ibm.com>
      Signed-off-by: NTrent Jaeger <tjaeger@cse.psu.edu>
      Acked-by: NJames Morris <jmorris@namei.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c8c05a8e
  16. 01 5月, 2006 1 次提交
  17. 21 3月, 2006 4 次提交
    • A
      [SECURITY] getpeersec: Fix build breakage · c841aa03
      Arnaldo Carvalho de Melo 提交于
      A recent changeset removes dummy_socket_getpeersec, replacing it with
      two new functions, but still references the removed function in the
      security_fixup_ops table, fix it by doing the replacement operation in
      the fixup table too.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c841aa03
    • C
      [SECURITY]: TCP/UDP getpeersec · 2c7946a7
      Catherine Zhang 提交于
      This patch implements an application of the LSM-IPSec networking
      controls whereby an application can determine the label of the
      security association its TCP or UDP sockets are currently connected to
      via getsockopt and the auxiliary data mechanism of recvmsg.
      
      Patch purpose:
      
      This patch enables a security-aware application to retrieve the
      security context of an IPSec security association a particular TCP or
      UDP socket is using.  The application can then use this security
      context to determine the security context for processing on behalf of
      the peer at the other end of this connection.  In the case of UDP, the
      security context is for each individual packet.  An example
      application is the inetd daemon, which could be modified to start
      daemons running at security contexts dependent on the remote client.
      
      Patch design approach:
      
      - Design for TCP
      The patch enables the SELinux LSM to set the peer security context for
      a socket based on the security context of the IPSec security
      association.  The application may retrieve this context using
      getsockopt.  When called, the kernel determines if the socket is a
      connected (TCP_ESTABLISHED) TCP socket and, if so, uses the dst_entry
      cache on the socket to retrieve the security associations.  If a
      security association has a security context, the context string is
      returned, as for UNIX domain sockets.
      
      - Design for UDP
      Unlike TCP, UDP is connectionless.  This requires a somewhat different
      API to retrieve the peer security context.  With TCP, the peer
      security context stays the same throughout the connection, thus it can
      be retrieved at any time between when the connection is established
      and when it is torn down.  With UDP, each read/write can have
      different peer and thus the security context might change every time.
      As a result the security context retrieval must be done TOGETHER with
      the packet retrieval.
      
      The solution is to build upon the existing Unix domain socket API for
      retrieving user credentials.  Linux offers the API for obtaining user
      credentials via ancillary messages (i.e., out of band/control messages
      that are bundled together with a normal message).
      
      Patch implementation details:
      
      - Implementation for TCP
      The security context can be retrieved by applications using getsockopt
      with the existing SO_PEERSEC flag.  As an example (ignoring error
      checking):
      
      getsockopt(sockfd, SOL_SOCKET, SO_PEERSEC, optbuf, &optlen);
      printf("Socket peer context is: %s\n", optbuf);
      
      The SELinux function, selinux_socket_getpeersec, is extended to check
      for labeled security associations for connected (TCP_ESTABLISHED ==
      sk->sk_state) TCP sockets only.  If so, the socket has a dst_cache of
      struct dst_entry values that may refer to security associations.  If
      these have security associations with security contexts, the security
      context is returned.
      
      getsockopt returns a buffer that contains a security context string or
      the buffer is unmodified.
      
      - Implementation for UDP
      To retrieve the security context, the application first indicates to
      the kernel such desire by setting the IP_PASSSEC option via
      getsockopt.  Then the application retrieves the security context using
      the auxiliary data mechanism.
      
      An example server application for UDP should look like this:
      
      toggle = 1;
      toggle_len = sizeof(toggle);
      
      setsockopt(sockfd, SOL_IP, IP_PASSSEC, &toggle, &toggle_len);
      recvmsg(sockfd, &msg_hdr, 0);
      if (msg_hdr.msg_controllen > sizeof(struct cmsghdr)) {
          cmsg_hdr = CMSG_FIRSTHDR(&msg_hdr);
          if (cmsg_hdr->cmsg_len <= CMSG_LEN(sizeof(scontext)) &&
              cmsg_hdr->cmsg_level == SOL_IP &&
              cmsg_hdr->cmsg_type == SCM_SECURITY) {
              memcpy(&scontext, CMSG_DATA(cmsg_hdr), sizeof(scontext));
          }
      }
      
      ip_setsockopt is enhanced with a new socket option IP_PASSSEC to allow
      a server socket to receive security context of the peer.  A new
      ancillary message type SCM_SECURITY.
      
      When the packet is received we get the security context from the
      sec_path pointer which is contained in the sk_buff, and copy it to the
      ancillary message space.  An additional LSM hook,
      selinux_socket_getpeersec_udp, is defined to retrieve the security
      context from the SELinux space.  The existing function,
      selinux_socket_getpeersec does not suit our purpose, because the
      security context is copied directly to user space, rather than to
      kernel space.
      
      Testing:
      
      We have tested the patch by setting up TCP and UDP connections between
      applications on two machines using the IPSec policies that result in
      labeled security associations being built.  For TCP, we can then
      extract the peer security context using getsockopt on either end.  For
      UDP, the receiving end can retrieve the security context using the
      auxiliary data mechanism of recvmsg.
      Signed-off-by: NCatherine Zhang <cxzhang@watson.ibm.com>
      Acked-by: NJames Morris <jmorris@namei.org>
      Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2c7946a7
    • D
      [PATCH] Miscellaneous bug and warning fixes · 7306a0b9
      Dustin Kirkland 提交于
      This patch fixes a couple of bugs revealed in new features recently
      added to -mm1:
      * fixes warnings due to inconsistent use of const struct inode *inode
      * fixes bug that prevent a kernel from booting with audit on, and SELinux off
        due to a missing function in security/dummy.c
      * fixes a bug that throws spurious audit_panic() messages due to a missing
        return just before an error_path label
      * some reasonable house cleaning in audit_ipc_context(),
        audit_inode_context(), and audit_log_task_context()
      Signed-off-by: NDustin Kirkland <dustin.kirkland@us.ibm.com>
      Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
      7306a0b9
    • D
      [PATCH] Capture selinux subject/object context information. · 8c8570fb
      Dustin Kirkland 提交于
      This patch extends existing audit records with subject/object context
      information. Audit records associated with filesystem inodes, ipc, and
      tasks now contain SELinux label information in the field "subj" if the
      item is performing the action, or in "obj" if the item is the receiver
      of an action.
      
      These labels are collected via hooks in SELinux and appended to the
      appropriate record in the audit code.
      
      This additional information is required for Common Criteria Labeled
      Security Protection Profile (LSPP).
      
      [AV: fixed kmalloc flags use]
      [folded leak fixes]
      [folded cleanup from akpm (kfree(NULL)]
      [folded audit_inode_context() leak fix]
      [folded akpm's fix for audit_ipc_perm() definition in case of !CONFIG_AUDIT]
      Signed-off-by: NDustin Kirkland <dustin.kirkland@us.ibm.com>
      Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      8c8570fb
  18. 12 1月, 2006 1 次提交
  19. 04 1月, 2006 1 次提交
    • T
      [LSM-IPSec]: Security association restriction. · df71837d
      Trent Jaeger 提交于
      This patch series implements per packet access control via the
      extension of the Linux Security Modules (LSM) interface by hooks in
      the XFRM and pfkey subsystems that leverage IPSec security
      associations to label packets.  Extensions to the SELinux LSM are
      included that leverage the patch for this purpose.
      
      This patch implements the changes necessary to the XFRM subsystem,
      pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a
      socket to use only authorized security associations (or no security
      association) to send/receive network packets.
      
      Patch purpose:
      
      The patch is designed to enable access control per packets based on
      the strongly authenticated IPSec security association.  Such access
      controls augment the existing ones based on network interface and IP
      address.  The former are very coarse-grained, and the latter can be
      spoofed.  By using IPSec, the system can control access to remote
      hosts based on cryptographic keys generated using the IPSec mechanism.
      This enables access control on a per-machine basis or per-application
      if the remote machine is running the same mechanism and trusted to
      enforce the access control policy.
      
      Patch design approach:
      
      The overall approach is that policy (xfrm_policy) entries set by
      user-level programs (e.g., setkey for ipsec-tools) are extended with a
      security context that is used at policy selection time in the XFRM
      subsystem to restrict the sockets that can send/receive packets via
      security associations (xfrm_states) that are built from those
      policies.
      
      A presentation available at
      www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf
      from the SELinux symposium describes the overall approach.
      
      Patch implementation details:
      
      On output, the policy retrieved (via xfrm_policy_lookup or
      xfrm_sk_policy_lookup) must be authorized for the security context of
      the socket and the same security context is required for resultant
      security association (retrieved or negotiated via racoon in
      ipsec-tools).  This is enforced in xfrm_state_find.
      
      On input, the policy retrieved must also be authorized for the socket
      (at __xfrm_policy_check), and the security context of the policy must
      also match the security association being used.
      
      The patch has virtually no impact on packets that do not use IPSec.
      The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as
      before.
      
      Also, if IPSec is used without security contexts, the impact is
      minimal.  The LSM must allow such policies to be selected for the
      combination of socket and remote machine, but subsequent IPSec
      processing proceeds as in the original case.
      
      Testing:
      
      The pfkey interface is tested using the ipsec-tools.  ipsec-tools have
      been modified (a separate ipsec-tools patch is available for version
      0.5) that supports assignment of xfrm_policy entries and security
      associations with security contexts via setkey and the negotiation
      using the security contexts via racoon.
      
      The xfrm_user interface is tested via ad hoc programs that set
      security contexts.  These programs are also available from me, and
      contain programs for setting, getting, and deleting policy for testing
      this interface.  Testing of sa functions was done by tracing kernel
      behavior.
      Signed-off-by: NTrent Jaeger <tjaeger@cse.psu.edu>
      Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      df71837d
  20. 31 10月, 2005 2 次提交
    • D
      [PATCH] Keys: Add LSM hooks for key management [try #3] · 29db9190
      David Howells 提交于
      The attached patch adds LSM hooks for key management facilities. The notable
      changes are:
      
       (1) The key struct now supports a security pointer for the use of security
           modules. This will permit key labelling and restrictions on which
           programs may access a key.
      
       (2) Security modules get a chance to note (or abort) the allocation of a key.
      
       (3) The key permission checking can now be enhanced by the security modules;
           the permissions check consults LSM if all other checks bear out.
      
       (4) The key permissions checking functions now return an error code rather
           than a boolean value.
      
       (5) An extra permission has been added to govern the modification of
           attributes (UID, GID, permissions).
      
      Note that there isn't an LSM hook specifically for each keyctl() operation,
      but rather the permissions hook allows control of individual operations based
      on the permission request bits.
      
      Key management access control through LSM is enabled by automatically if both
      CONFIG_KEYS and CONFIG_SECURITY are enabled.
      
      This should be applied on top of the patch ensubjected:
      
      	[PATCH] Keys: Possessor permissions should be additive
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NChris Wright <chrisw@osdl.org>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      29db9190
    • J
      [PATCH] SELinux: canonicalize getxattr() · d381d8a9
      James Morris 提交于
      This patch allows SELinux to canonicalize the value returned from
      getxattr() via the security_inode_getsecurity() hook, which is called after
      the fs level getxattr() function.
      
      The purpose of this is to allow the in-core security context for an inode
      to override the on-disk value.  This could happen in cases such as
      upgrading a system to a different labeling form (e.g.  standard SELinux to
      MLS) without needing to do a full relabel of the filesystem.
      
      In such cases, we want getxattr() to return the canonical security context
      that the kernel is using rather than what is stored on disk.
      
      The implementation hooks into the inode_getsecurity(), adding another
      parameter to indicate the result of the preceding fs-level getxattr() call,
      so that SELinux knows whether to compare a value obtained from disk with
      the kernel value.
      
      We also now allow getxattr() to work for mountpoint labeled filesystems
      (i.e.  mount with option context=foo_t), as we are able to return the
      kernel value to the user.
      Signed-off-by: NJames Morris <jmorris@namei.org>
      Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      d381d8a9
  21. 28 10月, 2005 1 次提交