1. 13 Sep, 2011 2 commits
    • Tetsuo Handa's avatar
      TOMOYO: Add socket operation restriction support. · 059d84db
      Tetsuo Handa authored
      
      
      This patch adds support for permission checks for PF_INET/PF_INET6/PF_UNIX
      socket's bind()/listen()/connect()/send() operations.
      Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      059d84db
    • Tetsuo Handa's avatar
      TOMOYO: Add environment variable name restriction support. · d58e0da8
      Tetsuo Handa authored
      
      
      This patch adds support for checking environment variable's names.
      Although TOMOYO already provides ability to check argv[]/envp[] passed to
      execve() requests,
      
        file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="bar"
      
      will reject execution of /bin/sh if environment variable LD_LIBRARY_PATH is not
      defined. To grant execution of /bin/sh if LD_LIBRARY_PATH is not defined,
      administrators have to specify like
      
        file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="/system/lib"
        file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]=NULL
      
      . Since there are many environment variables whereas conditional checks are
      applied as "&&", it is difficult to cover all combinations. Therefore, this
      patch supports conditional checks that are applied as "||", by specifying like
      
        file execute /bin/sh
        misc env LD_LIBRARY_PATH exec.envp["LD_LIBRARY_PATH"]="/system/lib"
      
      which means "grant execution of /bin/sh if environment variable is not defined
      or is defined and its value is /system/lib".
      Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      d58e0da8
  2. 09 Sep, 2011 18 commits
  3. 23 Aug, 2011 2 commits
  4. 22 Aug, 2011 8 commits
    • David Howells's avatar
      KEYS: Correctly destroy key payloads when their keytype is removed · 0c061b57
      David Howells authored
      unregister_key_type() has code to mark a key as dead and make it unavailable in
      one loop and then destroy all those unavailable key payloads in the next loop.
      However, the loop to mark keys dead renders the key undetectable to the second
      loop by changing the key type pointer also.
      
      Fix this by the following means:
      
       (1) The key code has two garbage collectors: one deletes unreferenced keys and
           the other alters keyrings to delete links to old dead, revoked and expired
           keys.  They can end up holding each other up as both want to scan the key
           serial tree under spinlock.  Combine these into a single routine.
      
       (2) Move the dead key marking, dead link removal and dead key removal into the
           garbage collector as a three phase process running over the three cycles
           of the normal garbage collection procedure.  This is tracked by the
           KEY_GC_REAPING_DEAD_1, _2 and _3 state flags.
      
           unregister_key_type() then just unlinks the key type from the list, wakes
           up the garbage collector and waits for the third phase to complete.
      
       (3) Downgrade the key types sem in unregister_key_type() once it has deleted
           the key type from the list so that it doesn't block the keyctl() syscall.
      
       (4) Dead keys that cannot be simply removed in the third phase have their
           payloads destroyed with the key's semaphore write-locked to prevent
           interference by the keyctl() syscall.  There should be no in-kernel users
           of dead keys of that type by the point of unregistration, though keyctl()
           may be holding a reference.
      
       (5) Only perform timer recalculation in the GC if the timer actually expired.
           If it didn't, we'll get another cycle when it goes off - and if the key
           that actually triggered it has been removed, it's not a problem.
      
       (6) Only garbage collect link if the timer expired or if we're doing dead key
           clean up phase 2.
      
       (7) As only key_garbage_collector() is permitted to use rb_erase() on the key
           serial tree, it doesn't need to revalidate its cursor after dropping the
           spinlock as the node the cursor points to must still exist in the tree.
      
       (8) Drop the spinlock in the GC if there is contention on it or if we need to
           reschedule.  After dealing with that, get the spinlock again and resume
           scanning.
      
      This has been tested in the following ways:
      
       (1) Run the keyutils testsuite against it.
      
       (2) Using the AF_RXRPC and RxKAD modules to test keytype removal:
      
           Load the rxrpc_s key type:
      
      	# insmod /tmp/af-rxrpc.ko
      	# insmod /tmp/rxkad.ko
      
           Create a key (http://people.redhat.com/~dhowells/rxrpc/listen.c
      
      ):
      
      	# /tmp/listen &
      	[1] 8173
      
           Find the key:
      
      	# grep rxrpc_s /proc/keys
      	091086e1 I--Q--     1 perm 39390000     0     0 rxrpc_s   52:2
      
           Link it to a session keyring, preferably one with a higher serial number:
      
      	# keyctl link 0x20e36251 @s
      
           Kill the process (the key should remain as it's linked to another place):
      
      	# fg
      	/tmp/listen
      	^C
      
           Remove the key type:
      
      	rmmod rxkad
      	rmmod af-rxrpc
      
           This can be made a more effective test by altering the following part of
           the patch:
      
      	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
      		/* Make sure everyone revalidates their keys if we marked a
      		 * bunch as being dead and make sure all keyring ex-payloads
      		 * are destroyed.
      		 */
      		kdebug("dead sync");
      		synchronize_rcu();
      
           To call synchronize_rcu() in GC phase 1 instead.  That causes that the
           keyring's old payload content to hang around longer until it's RCU
           destroyed - which usually happens after GC phase 3 is complete.  This
           allows the destroy_dead_key branch to be tested.
      Reported-by: default avatarBenjamin Coddington <bcodding@gmail.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      0c061b57
    • David Howells's avatar
      KEYS: The dead key link reaper should be non-reentrant · d199798b
      David Howells authored
      
      
      The dead key link reaper should be non-reentrant as it relies on global state
      to keep track of where it's got to when it returns to the work queue manager to
      give it some air.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      d199798b
    • David Howells's avatar
      KEYS: Make the key reaper non-reentrant · b072e9bc
      David Howells authored
      
      
      Make the key reaper non-reentrant by sticking it on the appropriate system work
      queue when we queue it.  This will allow it to have global state and drop
      locks.  It should probably be non-reentrant already as it may spend a long time
      holding the key serial spinlock, and so multiple entrants can spend long
      periods of time just sitting there spinning, waiting to get the lock.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      b072e9bc
    • David Howells's avatar
      KEYS: Move the unreferenced key reaper to the keys garbage collector file · 8bc16dea
      David Howells authored
      
      
      Move the unreferenced key reaper function to the keys garbage collector file
      as that's a more appropriate place with the dead key link reaper.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      8bc16dea
    • David Howells's avatar
      CRED: Fix prepare_kernel_cred() to provide a new thread_group_cred struct · 012146d0
      David Howells authored
      Fix prepare_kernel_cred() to provide a new, separate thread_group_cred struct
      otherwise when using request_key() ____call_usermodehelper() calls
      umh_keys_init() with the new creds pointing to init_tgcred, which
      umh_keys_init() then blithely alters.
      
      The problem can be demonstrated by:
      
      	# keyctl request2 user a debug:a @s
      	249681132
      	# grep req /proc/keys
      	079906a5 I--Q--     1 perm 1f3f0000     0     0 keyring   _req.249681132: 1/4
      	38ef1626 IR----     1 expd 0b010000     0     0 .request_ key:ee1d4ec pid:4371 ci:1
      
      The keyring _req.XXXX should have gone away, but something (init_tgcred) is
      pinning it.
      
      That key actually requested can then be removed and a new one created:
      
      	# keyctl unlink 249681132
      	1 links removed
      	[root@andromeda ~]# grep req /proc/keys
      	116cecac IR----     1 expd 0b010000     0     0 .request_ key:eeb4911 pid:4379 ci:1
      	36d1cbf8 I--Q--     1 perm 1f3f0000     0     0 keyring   _req.250300689: 1/4
      
      which causes the old _req keyring to go away and a new one to take its place.
      
      This is a consequence of the changes in:
      
      	commit 87966996
      	Author: David Howells <dhowells@redhat.com>
      	Date:   Fri Jun 17 11:25:59 2011 +0100
      	KEYS/DNS: Fix ____call_usermodehelper() to not lose the session keyring
      
      and:
      
      	commit 17f60a7d
      
      
      	Author: Eric Paris <eparis@redhat.com>
      	Date:   Fri Apr 1 17:07:50 2011 -0400
      	capabilites: allow the application of capability limits to usermode helpers
      
      After this patch is applied, the _req keyring and the .request_key key are
      cleaned up.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: Eric Paris <eparis@redhat.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      012146d0
    • David Howells's avatar
      KEYS: __key_link() should use the RCU deref wrapper for keyring payloads · 6d528b08
      David Howells authored
      
      
      __key_link() should use the RCU deref wrapper rcu_dereference_locked_keyring()
      for accessing keyring payloads rather than calling rcu_dereference_protected()
      directly.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      6d528b08
    • David Howells's avatar
      KEYS: keyctl_get_keyring_ID() should create a session keyring if create flag set · 3ecf1b4f
      David Howells authored
      
      
      The keyctl call:
      
      	keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1)
      
      should create a session keyring if the process doesn't have one of its own
      because the create flag argument is set - rather than subscribing to and
      returning the user-session keyring as:
      
      	keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0)
      
      will do.
      
      This can be tested by commenting out pam_keyinit in the /etc/pam.d files and
      running the following program a couple of times in a row:
      
      	#include <stdio.h>
      	#include <stdlib.h>
      	#include <keyutils.h>
      	int main(int argc, char *argv[])
      	{
      		key_serial_t uk, usk, sk, nsk;
      		uk  = keyctl_get_keyring_ID(KEY_SPEC_USER_KEYRING, 0);
      		usk = keyctl_get_keyring_ID(KEY_SPEC_USER_SESSION_KEYRING, 0);
      		sk  = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0);
      		nsk = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1);
      		printf("keys: %08x %08x %08x %08x\n", uk, usk, sk, nsk);
      		return 0;
      	}
      
      Without this patch, I see:
      
      	keys: 3975ddc7 119c0c66 119c0c66 119c0c66
      	keys: 3975ddc7 119c0c66 119c0c66 119c0c66
      
      With this patch, I see:
      
      	keys: 2cb4997b 34112878 34112878 17db2ce3
      	keys: 2cb4997b 34112878 34112878 39f3c73e
      
      As can be seen, the session keyring starts off the same as the user-session
      keyring each time, but with the patch a new session keyring is created when
      the create flag is set.
      Reported-by: default avatarGreg Wettstein <greg@enjellic.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarGreg Wettstein <greg@enjellic.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      3ecf1b4f
    • David Howells's avatar
      KEYS: If install_session_keyring() is given a keyring, it should install it · 99599537
      David Howells authored
      If install_session_keyring() is given a keyring, it should install it rather
      than just creating a new one anyway.  This was accidentally broken in:
      
      	commit d84f4f99
      
      
      	Author: David Howells <dhowells@redhat.com>
      	Date:   Fri Nov 14 10:39:23 2008 +1100
      	Subject: CRED: Inaugurate COW credentials
      
      The impact of that commit is that pam_keyinit no longer works correctly if
      'force' isn't specified against a login process. This is because:
      
      	keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0)
      
      now always creates a new session keyring and thus the check whether the session
      keyring and the user-session keyring are the same is always false.  This leads
      pam_keyinit to conclude that a session keyring is installed and it shouldn't be
      revoked by pam_keyinit here if 'revoke' is specified.
      
      Any system that specifies 'force' against pam_keyinit in the PAM configuration
      files for login methods (login, ssh, su -l, kdm, etc.) is not affected since
      that bypasses the broken check and forces the creation of a new session keyring
      anyway (for which the revoke flag is not cleared) - and any subsequent call to
      pam_keyinit really does have a session keyring already installed, and so the
      check works correctly there.
      
      Reverting to the previous behaviour will cause the kernel to subscribe the
      process to the user-session keyring as its session keyring if it doesn't have a
      session keyring of its own.  pam_keyinit will detect this and install a new
      session keyring anyway (and won't clear the revert flag).
      
      This can be tested by commenting out pam_keyinit in the /etc/pam.d files and
      running the following program a couple of times in a row:
      
      	#include <stdio.h>
      	#include <stdlib.h>
      	#include <keyutils.h>
      	int main(int argc, char *argv[])
      	{
      		key_serial_t uk, usk, sk;
      		uk = keyctl_get_keyring_ID(KEY_SPEC_USER_KEYRING, 0);
      		usk = keyctl_get_keyring_ID(KEY_SPEC_USER_SESSION_KEYRING, 0);
      		sk = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0);
      		printf("keys: %08x %08x %08x\n", uk, usk, sk);
      		return 0;
      	}
      
      Without the patch, I see:
      
      	keys: 3884e281 24c4dfcf 22825f8e
      	keys: 3884e281 24c4dfcf 068772be
      
      With the patch, I see:
      
      	keys: 26be9c83 0e755ce0 0e755ce0
      	keys: 26be9c83 0e755ce0 0e755ce0
      
      As can be seen, with the patch, the session keyring is the same as the
      user-session keyring each time; without the patch a new session keyring is
      generated each time.
      Reported-by: default avatarGreg Wettstein <greg@enjellic.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarGreg Wettstein <greg@enjellic.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      99599537
  5. 18 Aug, 2011 2 commits
  6. 16 Aug, 2011 1 commit
  7. 15 Aug, 2011 2 commits
  8. 12 Aug, 2011 2 commits
    • Zhi Li's avatar
      capabilities: do not grant full privs for setuid w/ file caps + no effective caps · 4d49f671
      Zhi Li authored
      
      
      A task (when !SECURE_NOROOT) which executes a setuid-root binary will
      obtain root privileges while executing that binary.  If the binary also
      has effective capabilities set, then only those capabilities will be
      granted.  The rationale is that the same binary can carry both setuid-root
      and the minimal file capability set, so that on a filesystem not
      supporting file caps the binary can still be executed with privilege,
      while on a filesystem supporting file caps it will run with minimal
      privilege.
      
      This special case currently does NOT happen if there are file capabilities
      but no effective capabilities.  Since capability-aware programs can very
      well start with empty pE but populated pP and move those caps to pE when
      needed.  In other words, if the file has file capabilities but NOT
      effective capabilities, then we should do the same thing as if there
      were file capabilities, and not grant full root privileges.
      
      This patchset does that.
      
      (Changelog by Serge Hallyn).
      Signed-off-by: default avatarZhi Li <lizhi1215@gmail.com>
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      4d49f671
    • Mimi Zohar's avatar
      CIFS: remove local xattr definitions · f995e740
      Mimi Zohar authored
      Local XATTR_TRUSTED_PREFIX_LEN and XATTR_SECURITY_PREFIX_LEN definitions
      redefined ones in 'linux/xattr.h'. This was caused by commit 9d8f13ba
      
      
      ("security: new security_inode_init_security API adds function callback")
      including 'linux/xattr.h' in 'linux/security.h'.
      
      In file included from include/linux/security.h:39,
                       from include/net/sock.h:54,
                       from fs/cifs/cifspdu.h:25,
                       from fs/cifs/xattr.c:26:
      
      This patch removes the local definitions.
      Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarMimi Zohar <zohar@us.ibm.com>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      f995e740
  9. 11 Aug, 2011 2 commits
  10. 09 Aug, 2011 1 commit