1. 04 10月, 2006 3 次提交
  2. 30 6月, 2006 1 次提交
  3. 27 6月, 2006 2 次提交
  4. 23 6月, 2006 2 次提交
    • D
      [PATCH] Keys: Fix race between two instantiators of a key · 04c567d9
      David Howells 提交于
      Add a revocation notification method to the key type and calls it whilst
      the key's semaphore is still write-locked after setting the revocation
      flag.
      
      The patch then uses this to maintain a reference on the task_struct of the
      process that calls request_key() for as long as the authorisation key
      remains unrevoked.
      
      This fixes a potential race between two processes both of which have
      assumed the authority to instantiate a key (one may have forked the other
      for example).  The problem is that there's no locking around the check for
      revocation of the auth key and the use of the task_struct it points to, nor
      does the auth key keep a reference on the task_struct.
      
      Access to the "context" pointer in the auth key must thenceforth be done
      with the auth key semaphore held.  The revocation method is called with the
      target key semaphore held write-locked and the search of the context
      process's keyrings is done with the auth key semaphore read-locked.
      
      The check for the revocation state of the auth key just prior to searching
      it is done after the auth key is read-locked for the search.  This ensures
      that the auth key can't be revoked between the check and the search.
      
      The revocation notification method is added so that the context task_struct
      can be released as soon as instantiation happens rather than waiting for
      the auth key to be destroyed, thus avoiding the unnecessary pinning of the
      requesting process.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      04c567d9
    • M
      [PATCH] selinux: add hooks for key subsystem · d720024e
      Michael LeMay 提交于
      Introduce SELinux hooks to support the access key retention subsystem
      within the kernel.  Incorporate new flask headers from a modified version
      of the SELinux reference policy, with support for the new security class
      representing retained keys.  Extend the "key_alloc" security hook with a
      task parameter representing the intended ownership context for the key
      being allocated.  Attach security information to root's default keyrings
      within the SELinux initialization routine.
      
      Has passed David's testsuite.
      Signed-off-by: NMichael LeMay <mdlemay@epoch.ncsc.mil>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      Acked-by: NChris Wright <chrisw@sous-sol.org>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      d720024e
  5. 09 1月, 2006 3 次提交
    • D
      [PATCH] keys: Permit running process to instantiate keys · b5f545c8
      David Howells 提交于
      Make it possible for a running process (such as gssapid) to be able to
      instantiate a key, as was requested by Trond Myklebust for NFS4.
      
      The patch makes the following changes:
      
       (1) A new, optional key type method has been added. This permits a key type
           to intercept requests at the point /sbin/request-key is about to be
           spawned and do something else with them - passing them over the
           rpc_pipefs files or netlink sockets for instance.
      
           The uninstantiated key, the authorisation key and the intended operation
           name are passed to the method.
      
       (2) The callout_info is no longer passed as an argument to /sbin/request-key
           to prevent unauthorised viewing of this data using ps or by looking in
           /proc/pid/cmdline.
      
           This means that the old /sbin/request-key program will not work with the
           patched kernel as it will expect to see an extra argument that is no
           longer there.
      
           A revised keyutils package will be made available tomorrow.
      
       (3) The callout_info is now attached to the authorisation key. Reading this
           key will retrieve the information.
      
       (4) A new field has been added to the task_struct. This holds the
           authorisation key currently active for a thread. Searches now look here
           for the caller's set of keys rather than looking for an auth key in the
           lowest level of the session keyring.
      
           This permits a thread to be servicing multiple requests at once and to
           switch between them. Note that this is per-thread, not per-process, and
           so is usable in multithreaded programs.
      
           The setting of this field is inherited across fork and exec.
      
       (5) A new keyctl function (KEYCTL_ASSUME_AUTHORITY) has been added that
           permits a thread to assume the authority to deal with an uninstantiated
           key. Assumption is only permitted if the authorisation key associated
           with the uninstantiated key is somewhere in the thread's keyrings.
      
           This function can also clear the assumption.
      
       (6) A new magic key specifier has been added to refer to the currently
           assumed authorisation key (KEY_SPEC_REQKEY_AUTH_KEY).
      
       (7) Instantiation will only proceed if the appropriate authorisation key is
           assumed first. The assumed authorisation key is discarded if
           instantiation is successful.
      
       (8) key_validate() is moved from the file of request_key functions to the
           file of permissions functions.
      
       (9) The documentation is updated.
      
      From: <Valdis.Kletnieks@vt.edu>
      
          Build fix.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Cc: Alexander Zangerl <az@bond.edu.au>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b5f545c8
    • D
      [PATCH] keys: Discard duplicate keys from a keyring on link · cab8eb59
      David Howells 提交于
      Cause any links within a keyring to keys that match a key to be linked into
      that keyring to be discarded as a link to the new key is added.  The match is
      contingent on the type and description strings being the same.
      
      This permits requests, adds and searches to displace negative, expired,
      revoked and dead keys easily.  After some discussion it was concluded that
      duplicate valid keys should probably be discarded also as they would otherwise
      hide the new key.
      
      Since request_key() is intended to be the primary method by which keys are
      added to a keyring, duplicate valid keys wouldn't be an issue there as that
      function would return an existing match in preference to creating a new key.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Cc: Alexander Zangerl <az@bond.edu.au>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      cab8eb59
    • D
      [PATCH] keys: Permit key expiry time to be set · 017679c4
      David Howells 提交于
      Add a new keyctl function that allows the expiry time to be set on a key or
      removed from a key, provided the caller has attribute modification access.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Cc: Alexander Zangerl <az@bond.edu.au>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      017679c4
  6. 07 1月, 2006 1 次提交
  7. 31 10月, 2005 1 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
  8. 09 10月, 2005 1 次提交
  9. 29 9月, 2005 1 次提交
    • D
      [PATCH] Keys: Add possessor permissions to keys [try #3] · 664cceb0
      David Howells 提交于
      The attached patch adds extra permission grants to keys for the possessor of a
      key in addition to the owner, group and other permissions bits. This makes
      SUID binaries easier to support without going as far as labelling keys and key
      targets using the LSM facilities.
      
      This patch adds a second "pointer type" to key structures (struct key_ref *)
      that can have the bottom bit of the address set to indicate the possession of
      a key. This is propagated through searches from the keyring to the discovered
      key. It has been made a separate type so that the compiler can spot attempts
      to dereference a potentially incorrect pointer.
      
      The "possession" attribute can't be attached to a key structure directly as
      it's not an intrinsic property of a key.
      
      Pointers to keys have been replaced with struct key_ref *'s wherever
      possession information needs to be passed through.
      
      This does assume that the bottom bit of the pointer will always be zero on
      return from kmem_cache_alloc().
      
      The key reference type has been made into a typedef so that at least it can be
      located in the sources, even though it's basically a pointer to an undefined
      type. I've also renamed the accessor functions to be more useful, and all
      reference variables should now end in "_ref".
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      664cceb0
  10. 24 6月, 2005 2 次提交
    • D
      [PATCH] Keys: Make request-key create an authorisation key · 3e30148c
      David Howells 提交于
      The attached patch makes the following changes:
      
       (1) There's a new special key type called ".request_key_auth".
      
           This is an authorisation key for when one process requests a key and
           another process is started to construct it. This type of key cannot be
           created by the user; nor can it be requested by kernel services.
      
           Authorisation keys hold two references:
      
           (a) Each refers to a key being constructed. When the key being
           	 constructed is instantiated the authorisation key is revoked,
           	 rendering it of no further use.
      
           (b) The "authorising process". This is either:
      
           	 (i) the process that called request_key(), or:
      
           	 (ii) if the process that called request_key() itself had an
           	      authorisation key in its session keyring, then the authorising
           	      process referred to by that authorisation key will also be
           	      referred to by the new authorisation key.
      
      	 This means that the process that initiated a chain of key requests
      	 will authorise the lot of them, and will, by default, wind up with
      	 the keys obtained from them in its keyrings.
      
       (2) request_key() creates an authorisation key which is then passed to
           /sbin/request-key in as part of a new session keyring.
      
       (3) When request_key() is searching for a key to hand back to the caller, if
           it comes across an authorisation key in the session keyring of the
           calling process, it will also search the keyrings of the process
           specified therein and it will use the specified process's credentials
           (fsuid, fsgid, groups) to do that rather than the calling process's
           credentials.
      
           This allows a process started by /sbin/request-key to find keys belonging
           to the authorising process.
      
       (4) A key can be read, even if the process executing KEYCTL_READ doesn't have
           direct read or search permission if that key is contained within the
           keyrings of a process specified by an authorisation key found within the
           calling process's session keyring, and is searchable using the
           credentials of the authorising process.
      
           This allows a process started by /sbin/request-key to read keys belonging
           to the authorising process.
      
       (5) The magic KEY_SPEC_*_KEYRING key IDs when passed to KEYCTL_INSTANTIATE or
           KEYCTL_NEGATE will specify a keyring of the authorising process, rather
           than the process doing the instantiation.
      
       (6) One of the process keyrings can be nominated as the default to which
           request_key() should attach new keys if not otherwise specified. This is
           done with KEYCTL_SET_REQKEY_KEYRING and one of the KEY_REQKEY_DEFL_*
           constants. The current setting can also be read using this call.
      
       (7) request_key() is partially interruptible. If it is waiting for another
           process to finish constructing a key, it can be interrupted. This permits
           a request-key cycle to be broken without recourse to rebooting.
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      Signed-Off-By: NBenoit Boissinot <benoit.boissinot@ens-lyon.org>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3e30148c
    • D
      [PATCH] keys: Discard key spinlock and use RCU for key payload · 76d8aeab
      David Howells 提交于
      The attached patch changes the key implementation in a number of ways:
      
       (1) It removes the spinlock from the key structure.
      
       (2) The key flags are now accessed using atomic bitops instead of
           write-locking the key spinlock and using C bitwise operators.
      
           The three instantiation flags are dealt with with the construction
           semaphore held during the request_key/instantiate/negate sequence, thus
           rendering the spinlock superfluous.
      
           The key flags are also now bit numbers not bit masks.
      
       (3) The key payload is now accessed using RCU. This permits the recursive
           keyring search algorithm to be simplified greatly since no locks need be
           taken other than the usual RCU preemption disablement. Searching now does
           not require any locks or semaphores to be held; merely that the starting
           keyring be pinned.
      
       (4) The keyring payload now includes an RCU head so that it can be disposed
           of by call_rcu(). This requires that the payload be copied on unlink to
           prevent introducing races in copy-down vs search-up.
      
       (5) The user key payload is now a structure with the data following it. It
           includes an RCU head like the keyring payload and for the same reason. It
           also contains a data length because the data length in the key may be
           changed on another CPU whilst an RCU protected read is in progress on the
           payload. This would then see the supposed RCU payload and the on-key data
           length getting out of sync.
      
           I'm tempted to drop the key's datalen entirely, except that it's used in
           conjunction with quota management and so is a little tricky to get rid
           of.
      
       (6) Update the keys documentation.
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      76d8aeab
  11. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4