Commit Graph

56 Commits

Author SHA1 Message Date
Matthew Garrett 1a3881d305 apparmor: Fix regression in profile conflict logic
The intended behaviour in apparmor profile matching is to flag a
conflict if two profiles match equally well. However, right now a
conflict is generated if another profile has the same match length even
if that profile doesn't actually match. Fix the logic so we only
generate a conflict if the profiles match.

Fixes: 844b8292b6 ("apparmor: ensure that undecidable profile attachments fail")
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-01-12 15:56:50 -08:00
John Johansen 5d7c44ef5e apparmor: fix locking when creating a new complain profile.
Break the per cpu buffer atomic section when creating a new null
complain profile. In learning mode this won't matter and we can
safely re-aquire the buffer.

This fixes the following lockdep BUG trace
   nov. 14 14:09:09 cyclope audit[7152]: AVC apparmor="ALLOWED" operation="exec" profile="/usr/sbin/sssd" name="/usr/sbin/adcli" pid=7152 comm="sssd_be" requested_mask="x" denied_mask="x" fsuid=0 ouid=0 target="/usr/sbin/sssd//null-/usr/sbin/adcli"
    nov. 14 14:09:09 cyclope kernel: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
    nov. 14 14:09:09 cyclope kernel: in_atomic(): 1, irqs_disabled(): 0, pid: 7152, name: sssd_be
    nov. 14 14:09:09 cyclope kernel: 1 lock held by sssd_be/7152:
    nov. 14 14:09:09 cyclope kernel:  #0:  (&sig->cred_guard_mutex){....}, at: [<ffffffff8182d53e>] prepare_bprm_creds+0x4e/0x100
    nov. 14 14:09:09 cyclope kernel: CPU: 3 PID: 7152 Comm: sssd_be Not tainted 4.14.0prahal+intel #150
    nov. 14 14:09:09 cyclope kernel: Hardware name: LENOVO 20CDCTO1WW/20CDCTO1WW, BIOS GQET53WW (1.33 ) 09/15/2017
    nov. 14 14:09:09 cyclope kernel: Call Trace:
    nov. 14 14:09:09 cyclope kernel:  dump_stack+0xb0/0x135
    nov. 14 14:09:09 cyclope kernel:  ? _atomic_dec_and_lock+0x15b/0x15b
    nov. 14 14:09:09 cyclope kernel:  ? lockdep_print_held_locks+0xc4/0x130
    nov. 14 14:09:09 cyclope kernel:  ___might_sleep+0x29c/0x320
    nov. 14 14:09:09 cyclope kernel:  ? rq_clock+0xf0/0xf0
    nov. 14 14:09:09 cyclope kernel:  ? __kernel_text_address+0xd/0x40
    nov. 14 14:09:09 cyclope kernel:  __might_sleep+0x95/0x190
    nov. 14 14:09:09 cyclope kernel:  ? aa_new_null_profile+0x50a/0x960
    nov. 14 14:09:09 cyclope kernel:  __mutex_lock+0x13e/0x1a20
    nov. 14 14:09:09 cyclope kernel:  ? aa_new_null_profile+0x50a/0x960
    nov. 14 14:09:09 cyclope kernel:  ? save_stack+0x43/0xd0
    nov. 14 14:09:09 cyclope kernel:  ? kmem_cache_alloc_trace+0x13f/0x290
    nov. 14 14:09:09 cyclope kernel:  ? mutex_lock_io_nested+0x1880/0x1880
    nov. 14 14:09:09 cyclope kernel:  ? profile_transition+0x932/0x2d40
    nov. 14 14:09:09 cyclope kernel:  ? apparmor_bprm_set_creds+0x1479/0x1f70
    nov. 14 14:09:09 cyclope kernel:  ? security_bprm_set_creds+0x5a/0x80
    nov. 14 14:09:09 cyclope kernel:  ? prepare_binprm+0x366/0x980
    nov. 14 14:09:09 cyclope kernel:  ? do_execveat_common.isra.30+0x12a9/0x2350
    nov. 14 14:09:09 cyclope kernel:  ? SyS_execve+0x2c/0x40
    nov. 14 14:09:09 cyclope kernel:  ? do_syscall_64+0x228/0x650
    nov. 14 14:09:09 cyclope kernel:  ? entry_SYSCALL64_slow_path+0x25/0x25
    nov. 14 14:09:09 cyclope kernel:  ? deactivate_slab.isra.62+0x49d/0x5e0
    nov. 14 14:09:09 cyclope kernel:  ? save_stack_trace+0x16/0x20
    nov. 14 14:09:09 cyclope kernel:  ? init_object+0x88/0x90
    nov. 14 14:09:09 cyclope kernel:  ? ___slab_alloc+0x520/0x590
    nov. 14 14:09:09 cyclope kernel:  ? ___slab_alloc+0x520/0x590
    nov. 14 14:09:09 cyclope kernel:  ? aa_alloc_proxy+0xab/0x200
    nov. 14 14:09:09 cyclope kernel:  ? lock_downgrade+0x7e0/0x7e0
    nov. 14 14:09:09 cyclope kernel:  ? memcg_kmem_get_cache+0x970/0x970
    nov. 14 14:09:09 cyclope kernel:  ? kasan_unpoison_shadow+0x35/0x50
    nov. 14 14:09:09 cyclope kernel:  ? kasan_unpoison_shadow+0x35/0x50
    nov. 14 14:09:09 cyclope kernel:  ? kasan_kmalloc+0xad/0xe0
    nov. 14 14:09:09 cyclope kernel:  ? aa_alloc_proxy+0xab/0x200
    nov. 14 14:09:09 cyclope kernel:  ? kmem_cache_alloc_trace+0x13f/0x290
    nov. 14 14:09:09 cyclope kernel:  ? aa_alloc_proxy+0xab/0x200
    nov. 14 14:09:09 cyclope kernel:  ? aa_alloc_proxy+0xab/0x200
    nov. 14 14:09:09 cyclope kernel:  ? _raw_spin_unlock+0x22/0x30
    nov. 14 14:09:09 cyclope kernel:  ? vec_find+0xa0/0xa0
    nov. 14 14:09:09 cyclope kernel:  ? aa_label_init+0x6f/0x230
    nov. 14 14:09:09 cyclope kernel:  ? __label_insert+0x3e0/0x3e0
    nov. 14 14:09:09 cyclope kernel:  ? kmem_cache_alloc_trace+0x13f/0x290
    nov. 14 14:09:09 cyclope kernel:  ? aa_alloc_profile+0x58/0x200
    nov. 14 14:09:09 cyclope kernel:  mutex_lock_nested+0x16/0x20
    nov. 14 14:09:09 cyclope kernel:  ? mutex_lock_nested+0x16/0x20
    nov. 14 14:09:09 cyclope kernel:  aa_new_null_profile+0x50a/0x960
    nov. 14 14:09:09 cyclope kernel:  ? aa_fqlookupn_profile+0xdc0/0xdc0
    nov. 14 14:09:09 cyclope kernel:  ? aa_compute_fperms+0x4b5/0x640
    nov. 14 14:09:09 cyclope kernel:  ? disconnect.isra.2+0x1b0/0x1b0
    nov. 14 14:09:09 cyclope kernel:  ? aa_str_perms+0x8d/0xe0
    nov. 14 14:09:09 cyclope kernel:  profile_transition+0x932/0x2d40
    nov. 14 14:09:09 cyclope kernel:  ? up_read+0x1a/0x40
    nov. 14 14:09:09 cyclope kernel:  ? ext4_xattr_get+0x15c/0xaf0 [ext4]
    nov. 14 14:09:09 cyclope kernel:  ? x_table_lookup+0x190/0x190
    nov. 14 14:09:09 cyclope kernel:  ? ext4_xattr_ibody_get+0x590/0x590 [ext4]
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? ext4_xattr_security_get+0x1a/0x20 [ext4]
    nov. 14 14:09:09 cyclope kernel:  ? __vfs_getxattr+0x6d/0xa0
    nov. 14 14:09:09 cyclope kernel:  ? get_vfs_caps_from_disk+0x114/0x720
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? tsc_resume+0x10/0x10
    nov. 14 14:09:09 cyclope kernel:  ? get_vfs_caps_from_disk+0x720/0x720
    nov. 14 14:09:09 cyclope kernel:  ? native_sched_clock_from_tsc+0x201/0x2b0
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock_cpu+0x1b/0x170
    nov. 14 14:09:09 cyclope kernel:  ? find_held_lock+0x3c/0x1e0
    nov. 14 14:09:09 cyclope kernel:  ? rb_insert_color_cached+0x1660/0x1660
    nov. 14 14:09:09 cyclope kernel:  apparmor_bprm_set_creds+0x1479/0x1f70
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? handle_onexec+0x31d0/0x31d0
    nov. 14 14:09:09 cyclope kernel:  ? tsc_resume+0x10/0x10
    nov. 14 14:09:09 cyclope kernel:  ? graph_lock+0xd0/0xd0
    nov. 14 14:09:09 cyclope kernel:  ? tsc_resume+0x10/0x10
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock_cpu+0x1b/0x170
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock+0x9/0x10
    nov. 14 14:09:09 cyclope kernel:  ? sched_clock_cpu+0x1b/0x170
    nov. 14 14:09:09 cyclope kernel:  ? find_held_lock+0x3c/0x1e0
    nov. 14 14:09:09 cyclope kernel:  security_bprm_set_creds+0x5a/0x80
    nov. 14 14:09:09 cyclope kernel:  prepare_binprm+0x366/0x980
    nov. 14 14:09:09 cyclope kernel:  ? install_exec_creds+0x150/0x150
    nov. 14 14:09:09 cyclope kernel:  ? __might_fault+0x89/0xb0
    nov. 14 14:09:09 cyclope kernel:  ? up_read+0x40/0x40
    nov. 14 14:09:09 cyclope kernel:  ? get_user_arg_ptr.isra.18+0x2c/0x70
    nov. 14 14:09:09 cyclope kernel:  ? count.isra.20.constprop.32+0x7c/0xf0
    nov. 14 14:09:09 cyclope kernel:  do_execveat_common.isra.30+0x12a9/0x2350
    nov. 14 14:09:09 cyclope kernel:  ? prepare_bprm_creds+0x100/0x100
    nov. 14 14:09:09 cyclope kernel:  ? _raw_spin_unlock+0x22/0x30
    nov. 14 14:09:09 cyclope kernel:  ? deactivate_slab.isra.62+0x49d/0x5e0
    nov. 14 14:09:09 cyclope kernel:  ? save_stack_trace+0x16/0x20
    nov. 14 14:09:09 cyclope kernel:  ? init_object+0x88/0x90
    nov. 14 14:09:09 cyclope kernel:  ? ___slab_alloc+0x520/0x590
    nov. 14 14:09:09 cyclope kernel:  ? ___slab_alloc+0x520/0x590
    nov. 14 14:09:09 cyclope kernel:  ? kasan_check_write+0x14/0x20
    nov. 14 14:09:09 cyclope kernel:  ? memcg_kmem_get_cache+0x970/0x970
    nov. 14 14:09:09 cyclope kernel:  ? kasan_unpoison_shadow+0x35/0x50
    nov. 14 14:09:09 cyclope kernel:  ? glob_match+0x730/0x730
    nov. 14 14:09:09 cyclope kernel:  ? kmem_cache_alloc+0x225/0x280
    nov. 14 14:09:09 cyclope kernel:  ? getname_flags+0xb8/0x510
    nov. 14 14:09:09 cyclope kernel:  ? mm_fault_error+0x2e0/0x2e0
    nov. 14 14:09:09 cyclope kernel:  ? getname_flags+0xf6/0x510
    nov. 14 14:09:09 cyclope kernel:  ? ptregs_sys_vfork+0x10/0x10
    nov. 14 14:09:09 cyclope kernel:  SyS_execve+0x2c/0x40
    nov. 14 14:09:09 cyclope kernel:  do_syscall_64+0x228/0x650
    nov. 14 14:09:09 cyclope kernel:  ? syscall_return_slowpath+0x2f0/0x2f0
    nov. 14 14:09:09 cyclope kernel:  ? syscall_return_slowpath+0x167/0x2f0
    nov. 14 14:09:09 cyclope kernel:  ? prepare_exit_to_usermode+0x220/0x220
    nov. 14 14:09:09 cyclope kernel:  ? prepare_exit_to_usermode+0xda/0x220
    nov. 14 14:09:09 cyclope kernel:  ? perf_trace_sys_enter+0x1060/0x1060
    nov. 14 14:09:09 cyclope kernel:  ? __put_user_4+0x1c/0x30
    nov. 14 14:09:09 cyclope kernel:  entry_SYSCALL64_slow_path+0x25/0x25
    nov. 14 14:09:09 cyclope kernel: RIP: 0033:0x7f9320f23637
    nov. 14 14:09:09 cyclope kernel: RSP: 002b:00007fff783be338 EFLAGS: 00000202 ORIG_RAX: 000000000000003b
    nov. 14 14:09:09 cyclope kernel: RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9320f23637
    nov. 14 14:09:09 cyclope kernel: RDX: 0000558c35002a70 RSI: 0000558c3505bd10 RDI: 0000558c35018b90
    nov. 14 14:09:09 cyclope kernel: RBP: 0000558c34b63ae8 R08: 0000558c3505bd10 R09: 0000000000000080
    nov. 14 14:09:09 cyclope kernel: R10: 0000000000000095 R11: 0000000000000202 R12: 0000000000000001
    nov. 14 14:09:09 cyclope kernel: R13: 0000558c35018b90 R14: 0000558c3505bd18 R15: 0000558c3505bd10

Fixes: 4227c333f6 ("apparmor: Move path lookup to using preallocated buffers")
BugLink: http://bugs.launchpad.net/bugs/173228
Reported-by: Alban Browaeys <prahal@yahoo.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-11-21 02:17:15 -08:00
John Johansen 06d426d113 apparmor: fix profile attachment for special unconfined profiles
It used to be that unconfined would never attach. However that is not
the case anymore as some special profiles can be marked as unconfined,
that are not the namespaces unconfined profile, and may have an
attachment.

Fixes: f1bd904175 ("apparmor: add the base fns() for domain labels")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-11-21 02:17:15 -08:00
John Johansen 844b8292b6 apparmor: ensure that undecidable profile attachments fail
Profiles that have an undecidable overlap in their attachments are
being incorrectly handled. Instead of failing to attach the first one
encountered is being used.

eg.
  profile A /** { .. }
  profile B /*foo { .. }

have an unresolvable longest left attachment, they both have an exact
match on / and then have an overlapping expression that has no clear
winner.

Currently the winner will be the profile that is loaded first which
can result in non-deterministic behavior. Instead in this situation
the exec should fail.

Fixes: 898127c34e ("AppArmor: functions for domain transitions")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-11-21 02:17:14 -08:00
Linus Torvalds 79444df4e7 + Features
- in preparation for secid mapping add support for absolute root view
     based labels
   - add base infastructure for socket mediation
   - add mount mediation
   - add signal mediation
 
 + minor cleanups and changes
   - be defensive, ensure unconfined profiles have dfas initialized
   - add more debug asserts to apparmorfs
   - enable policy unpacking to audit different reasons for failure
   - cleanup conditional check for label in label_print
   - Redundant condition: prev_ns. in [label.c:1498]
 
 + Bug Fixes
   - fix regression in apparmorfs DAC access permissions
   - fix build failure on sparc caused by undeclared signals
   - fix sparse report of incorrect type assignment when freeing label proxies
   - fix race condition in null profile creation
   - Fix an error code in aafs_create()
   - Fix logical error in verify_header()
   - Fix shadowed local variable in unpack_trans_table()
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Merge tag 'apparmor-pr-2017-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "This is the apparmor pull request, similar to SELinux and seccomp.

  It's the same series that I was sent to James' security tree + one
  regression fix that was found after the series was sent to James and
  would have been sent for v4.14-rc2.

  Features:
  - in preparation for secid mapping add support for absolute root view
    based labels
  - add base infastructure for socket mediation
  - add mount mediation
  - add signal mediation

  minor cleanups and changes:
  - be defensive, ensure unconfined profiles have dfas initialized
  - add more debug asserts to apparmorfs
  - enable policy unpacking to audit different reasons for failure
  - cleanup conditional check for label in label_print
  - Redundant condition: prev_ns. in [label.c:1498]

  Bug Fixes:
  - fix regression in apparmorfs DAC access permissions
  - fix build failure on sparc caused by undeclared signals
  - fix sparse report of incorrect type assignment when freeing label proxies
  - fix race condition in null profile creation
  - Fix an error code in aafs_create()
  - Fix logical error in verify_header()
  - Fix shadowed local variable in unpack_trans_table()"

* tag 'apparmor-pr-2017-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: fix apparmorfs DAC access permissions
  apparmor: fix build failure on sparc caused by undeclared signals
  apparmor: fix incorrect type assignment when freeing proxies
  apparmor: ensure unconfined profiles have dfas initialized
  apparmor: fix race condition in null profile creation
  apparmor: move new_null_profile to after profile lookup fns()
  apparmor: add base infastructure for socket mediation
  apparmor: add more debug asserts to apparmorfs
  apparmor: make policy_unpack able to audit different info messages
  apparmor: add support for absolute root view based labels
  apparmor: cleanup conditional check for label in label_print
  apparmor: add mount mediation
  apparmor: add the ability to mediate signals
  apparmor: Redundant condition: prev_ns. in [label.c:1498]
  apparmor: Fix an error code in aafs_create()
  apparmor: Fix logical error in verify_header()
  apparmor: Fix shadowed local variable in unpack_trans_table()
2017-09-23 05:33:29 -10:00
John Johansen 2ea3ffb778 apparmor: add mount mediation
Add basic mount mediation. That allows controlling based on basic
mount parameters. It does not include special mount parameters for
apparmor, super block labeling, or any triggers for apparmor namespace
parameter modifications on pivot root.

default userspace policy rules have the form of
  MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT )

  MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ]
          [ '->' MOUNTPOINT FILEGLOB ]

  REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ]
            MOUNTPOINT FILEGLOB

  UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB

  MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' )
                       MOUNT FSTYPE EXPRESSION ]
		       [ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ]

  MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION )

  MOUNT FSTYPE LIST = Comma separated list of valid filesystem and
                      virtual filesystem types (eg ext4, debugfs, etc)

  MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION )

  MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS.

  MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' |
                  'noexec' | 'exec' | 'sync' | 'async' | 'remount' |
		  'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' |
		  'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' |
		  'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' |
		  'unbindable' | 'runbindable' | 'private' | 'rprivate' |
		  'slave' | 'rslave' | 'shared' | 'rshared' |
		  'relatime' | 'norelatime' | 'iversion' | 'noiversion' |
		  'strictatime' | 'nouser' | 'user' )

  MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ...

  PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ]
                    [ NEW ROOT FILEGLOB ]

  SOURCE FILEGLOB = FILEGLOB

  MOUNTPOINT FILEGLOB = FILEGLOB

eg.
  mount,
  mount /dev/foo,
  mount options=ro /dev/foo -> /mnt/,
  mount options in (ro,atime) /dev/foo -> /mnt/,
  mount options=ro options=atime,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:57 -07:00
Kees Cook 993b3ab064 apparmor: Refactor to remove bprm_secureexec hook
The AppArmor bprm_secureexec hook can be merged with the bprm_set_creds
hook since it's dealing with the same information, and all of the details
are finalized during the first call to the bprm_set_creds hook via
prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored
via bprm->called_set_creds).

Here, all the comments describe how secureexec is actually calculated
during bprm_set_creds, so this actually does it, drops the bprm flag that
was being used internally by AppArmor, and drops the bprm_secureexec hook.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
2017-08-01 12:03:06 -07:00
Kees Cook ddb4a1442d exec: Rename bprm->cred_prepared to called_set_creds
The cred_prepared bprm flag has a misleading name. It has nothing to do
with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has
been called. Rename this flag and improve its comment.

Cc: David Howells <dhowells@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
2017-08-01 12:02:48 -07:00
John Johansen e00b02bb6a apparmor: move change_profile mediation to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:47 -07:00
John Johansen 89dbf1962a apparmor: move change_hat mediation to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:46 -07:00
John Johansen 93c98a484c apparmor: move exec domain mediation to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:46 -07:00
John Johansen 98c3d18232 apparmor: update aa_audit_file() to use labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:43 -07:00
John Johansen b2d09ae449 apparmor: move ptrace checks to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:41 -07:00
John Johansen 637f688dc3 apparmor: switch from profiles to using labels on contexts
Begin the actual switch to using domain labels by storing them on
the context and converting the label to a singular profile where
possible.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:38 -07:00
John Johansen df8073c67f apparmor: convert aa_change_XXX bool parameters to flags
Instead of passing multiple booleans consolidate on a single flags
field.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:36 -07:00
John Johansen cf797c0e5e apparmor: convert to profile block critical sections
There are still a few places where profile replacement fails to update
and a stale profile is used for mediation. Fix this by moving to
accessing the current label through a critical section that will
always ensure mediation is using the current label regardless of
whether the tasks cred has been updated or not.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:34 -07:00
John Johansen fe864821d5 apparmor: move bprm_committing_creds/committed_creds to lsm.c
There is no reason to have the small stubs that don't use domain
private functions in domain.c, instead move them to lsm.c and make
them static.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:34 -07:00
John Johansen 2d679f3cb0 apparmor: switch from file_perms to aa_perms
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:30 -07:00
John Johansen 4227c333f6 apparmor: Move path lookup to using preallocated buffers
Dynamically allocating buffers is problematic and is an extra layer
that is a potntial point of failure and can slow down mediation.
Change path lookup to use the preallocated per cpu buffers.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:34 -07:00
John Johansen 72c8a76864 apparmor: allow profiles to provide info to disconnected paths
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:34 -07:00
Linus Torvalds f1ef09fde1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman:
 "There is a lot here. A lot of these changes result in subtle user
  visible differences in kernel behavior. I don't expect anything will
  care but I will revert/fix things immediately if any regressions show
  up.

  From Seth Forshee there is a continuation of the work to make the vfs
  ready for unpriviled mounts. We had thought the previous changes
  prevented the creation of files outside of s_user_ns of a filesystem,
  but it turns we missed the O_CREAT path. Ooops.

  Pavel Tikhomirov and Oleg Nesterov worked together to fix a long
  standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only
  children that are forked after the prctl are considered and not
  children forked before the prctl. The only known user of this prctl
  systemd forks all children after the prctl. So no userspace
  regressions will occur. Holding earlier forked children to the same
  rules as later forked children creates a semantic that is sane enough
  to allow checkpoing of processes that use this feature.

  There is a long delayed change by Nikolay Borisov to limit inotify
  instances inside a user namespace.

  Michael Kerrisk extends the API for files used to maniuplate
  namespaces with two new trivial ioctls to allow discovery of the
  hierachy and properties of namespaces.

  Konstantin Khlebnikov with the help of Al Viro adds code that when a
  network namespace exits purges it's sysctl entries from the dcache. As
  in some circumstances this could use a lot of memory.

  Vivek Goyal fixed a bug with stacked filesystems where the permissions
  on the wrong inode were being checked.

  I continue previous work on ptracing across exec. Allowing a file to
  be setuid across exec while being ptraced if the tracer has enough
  credentials in the user namespace, and if the process has CAP_SETUID
  in it's own namespace. Proc files for setuid or otherwise undumpable
  executables are now owned by the root in the user namespace of their
  mm. Allowing debugging of setuid applications in containers to work
  better.

  A bug I introduced with permission checking and automount is now
  fixed. The big change is to mark the mounts that the kernel initiates
  as a result of an automount. This allows the permission checks in sget
  to be safely suppressed for this kind of mount. As the permission
  check happened when the original filesystem was mounted.

  Finally a special case in the mount namespace is removed preventing
  unbounded chains in the mount hash table, and making the semantics
  simpler which benefits CRIU.

  The vfs fix along with related work in ima and evm I believe makes us
  ready to finish developing and merge fully unprivileged mounts of the
  fuse filesystem. The cleanups of the mount namespace makes discussing
  how to fix the worst case complexity of umount. The stacked filesystem
  fixes pave the way for adding multiple mappings for the filesystem
  uids so that efficient and safer containers can be implemented"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  proc/sysctl: Don't grab i_lock under sysctl_lock.
  vfs: Use upper filesystem inode in bprm_fill_uid()
  proc/sysctl: prune stale dentries during unregistering
  mnt: Tuck mounts under others instead of creating shadow/side mounts.
  prctl: propagate has_child_subreaper flag to every descendant
  introduce the walk_process_tree() helper
  nsfs: Add an ioctl() to return owner UID of a userns
  fs: Better permission checking for submounts
  exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction
  vfs: open() with O_CREAT should not create inodes with unknown ids
  nsfs: Add an ioctl() to return the namespace type
  proc: Better ownership of files for non-dumpable tasks in user namespaces
  exec: Remove LSM_UNSAFE_PTRACE_CAP
  exec: Test the ptracer's saved cred to see if the tracee can gain caps
  exec: Don't reset euid and egid when the tracee has CAP_SETUID
  inotify: Convert to using per-namespace limits
2017-02-23 20:33:51 -08:00
Eric W. Biederman 9227dd2a84 exec: Remove LSM_UNSAFE_PTRACE_CAP
With previous changes every location that tests for
LSM_UNSAFE_PTRACE_CAP also tests for LSM_UNSAFE_PTRACE making the
LSM_UNSAFE_PTRACE_CAP redundant, so remove it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-01-24 12:03:08 +13:00
John Johansen aa9a39ad8f apparmor: convert change_profile to use fqname later to give better control
Moving the use of fqname to later allows learning profiles to be based
on the fqname request instead of just the hname. It also allows cleaning
up some of the name parsing and lookup by allowing the use of
the fqlookupn_profile() lib fn.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:49 -08:00
John Johansen ef88a7ac55 apparmor: change aad apparmor_audit_data macro to a fn macro
The aad macro can replace aad strings when it is not intended to. Switch
to a fn macro so it is only applied when intended.

Also at the same time cleanup audit_data initialization by putting
common boiler plate behind a macro, and dropping the gfp_t parameter
which will become useless.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:47 -08:00
John Johansen 47f6e5cc73 apparmor: change op from int to const char *
Having ops be an integer that is an index into an op name table is
awkward and brittle. Every op change requires an edit for both the
op constant and a string in the table. Instead switch to using const
strings directly, eliminating the need for the table that needs to
be kept in sync.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:46 -08:00
John Johansen 55a26ebf63 apparmor: rename context abreviation cxt to the more standard ctx
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:45 -08:00
John Johansen 181f7c9776 apparmor: name null-XXX profiles after the executable
When possible its better to name a learning profile after the missing
profile in question. This allows for both more informative names and
for profile reuse.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:30 -08:00
John Johansen 98849dff90 apparmor: rename namespace to ns to improve code line lengths
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 00:42:16 -08:00
John Johansen cff281f686 apparmor: split apparmor policy namespaces code into its own file
Policy namespaces will be diverging from profile management and
expanding so put it in its own file.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 00:42:15 -08:00
John Johansen 3d40658c97 apparmor: fix change_hat not finding hat after policy replacement
After a policy replacement, the task cred may be out of date and need
to be updated. However change_hat is using the stale profiles from
the out of date cred resulting in either: a stale profile being applied
or, incorrect failure when searching for a hat profile as it has been
migrated to the new parent profile.

Fixes: 01e2b670aa (failure to find hat)
Fixes: 898127c34e (stale policy being applied)
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1000287
Cc: stable@vger.kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-11-21 18:01:28 +11:00
John Johansen f7da2de011 apparmor: ensure the target profile name is always audited
The target profile name was not being correctly audited in a few
cases because the target variable was not being set and gotos
passed the code to set it at apply:

Since it is always based on new_profile just drop the target var
and conditionally report based on new_profile.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen 9049a79221 apparmor: exec should not be returning ENOENT when it denies
The current behavior is confusing as it causes exec failures to report
the executable is missing instead of identifying that apparmor
caused the failure.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
Casey Schaufler b1d9e6b064 LSM: Switch to lists of hooks
Instead of using a vector of security operations
with explicit, special case stacking of the capability
and yama hooks use lists of hooks with capability and
yama hooks included as appropriate.

The security_operations structure is no longer required.
Instead, there is a union of the function pointers that
allows all the hooks lists to use a common mechanism for
list management while retaining typing. Each module
supplies an array describing the hooks it provides instead
of a sparsely populated security_operations structure.
The description includes the element that gets put on
the hook list, avoiding the issues surrounding individual
element allocation.

The method for registering security modules is changed to
reflect the information available. The method for removing
a module, currently only used by SELinux, has also changed.
It should be generic now, however if there are potential
race conditions based on ordering of hook removal that needs
to be addressed by the calling module.

The security hooks are called from the lists and the first
failure is returned.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2015-05-12 15:00:41 +10:00
Kees Cook 1d4457f999 sched: move no_new_privs into new atomic flags
Since seccomp transitions between threads requires updates to the
no_new_privs flag to be atomic, the flag must be part of an atomic flag
set. This moves the nnp flag into a separate task field, and introduces
accessors.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
2014-07-18 12:13:38 -07:00
Oleg Nesterov 51775fe736 apparmor: remove the "task" arg from may_change_ptraced_domain()
Unless task == current ptrace_parent(task) is not safe even under
rcu_read_lock() and most of the current users are not right.

So may_change_ptraced_domain(task) looks wrong as well. However it
is always called with task == current so the code is actually fine.
Remove this argument to make this fact clear.

Note: perhaps we should simply kill ptrace_parent(), it buys almost
nothing. And it is obviously racy, perhaps this should be fixed.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-10-29 21:34:18 -07:00
John Johansen dd0c6e86f6 apparmor: fix capability to not use the current task, during reporting
Mediation is based off of the cred but auditing includes the current
task which may not be related to the actual request.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-10-29 21:33:37 -07:00
John Johansen 038165070a apparmor: allow setting any profile into the unconfined state
Allow emulating the default profile behavior from boot, by allowing
loading of a profile in the unconfined state into a new NS.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:07 -07:00
John Johansen fa2ac468db apparmor: update how unconfined is handled
ns->unconfined is being used read side without locking, nor rcu but is
being updated when a namespace is removed. This works for the root ns
which is never removed but has a race window and can cause failures when
children namespaces are removed.

Also ns and ns->unconfined have a circular refcounting dependency that
is problematic and must be broken. Currently this is done incorrectly
when the namespace is destroyed.

Fix this by forward referencing unconfined via the replacedby infrastructure
instead of directly updating the ns->unconfined pointer.

Remove the circular refcount dependency by making the ns and its unconfined
profile share the same refcount.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen 77b071b340 apparmor: change how profile replacement update is done
remove the use of replaced by chaining and move to profile invalidation
and lookup to handle task replacement.

Replacement chaining can result in large chains of profiles being pinned
in memory when one profile in the chain is use. With implicit labeling
this will be even more of a problem, so move to a direct lookup method.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen 01e2b670aa apparmor: convert profile lists to RCU based locking
Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen 214beacaa7 apparmor: localize getting the security context to a few macros
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-04-28 00:39:35 -07:00
John Johansen 7a2871b566 apparmor: use common fn to clear task_context for domain transitions
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2013-04-28 00:36:20 -07:00
John Johansen 3cfcc19e0b apparmor: add utility function to get an arbitrary tasks profile.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2013-04-28 00:35:53 -07:00
John Johansen 04266236b1 apparmor: Remove -W1 warnings
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-By: Steve Beattie <sbeattie@ubuntu.com>
2013-04-28 00:35:18 -07:00
John Johansen 17322cc3f9 apparmor: fix auditing of domain transition failures due to incomplete policy
When policy specifies a transition to a profile that is not currently
loaded, it result in exec being denied.  However the failure is not being
audited correctly because the audit code is treating this as an allowed
permission and thus not reporting it.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-By: Steve Beattie <sbeattie@ubuntu.com>
2013-04-28 00:35:04 -07:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Eric W. Biederman 2db8145293 userns: Convert apparmor to use kuid and kgid where appropriate
Cc: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-21 03:13:21 -07:00
John Johansen c29bceb396 Fix execve behavior apparmor for PR_{GET,SET}_NO_NEW_PRIVS
Add support for AppArmor to explicitly fail requested domain transitions
if NO_NEW_PRIVS is set and the task is not unconfined.

Transitions from unconfined are still allowed because this always results
in a reduction of privileges.

Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>

v18: new acked-by, new description
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-14 11:13:18 +10:00
Andy Lutomirski 259e5e6c75 Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privs
With this change, calling
  prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)
disables privilege granting operations at execve-time.  For example, a
process will not be able to execute a setuid binary to change their uid
or gid if this bit is set.  The same is true for file capabilities.

Additionally, LSM_UNSAFE_NO_NEW_PRIVS is defined to ensure that
LSMs respect the requested behavior.

To determine if the NO_NEW_PRIVS bit is set, a task may call
  prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
It returns 1 if set and 0 if it is not set. If any of the arguments are
non-zero, it will return -1 and set errno to -EINVAL.
(PR_SET_NO_NEW_PRIVS behaves similarly.)

This functionality is desired for the proposed seccomp filter patch
series.  By using PR_SET_NO_NEW_PRIVS, it allows a task to modify the
system call behavior for itself and its child tasks without being
able to impact the behavior of a more privileged task.

Another potential use is making certain privileged operations
unprivileged.  For example, chroot may be considered "safe" if it cannot
affect privileged tasks.

Note, this patch causes execve to fail when PR_SET_NO_NEW_PRIVS is
set and AppArmor is in use.  It is fixed in a subsequent patch.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>

v18: updated change desc
v17: using new define values as per 3.4
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-14 11:13:18 +10:00
John Johansen 0421ea91dd apparmor: Fix change_onexec when called from a confined task
Fix failure in aa_change_onexec api when the request is made from a confined
task.  This failure was caused by two problems

 The AA_MAY_ONEXEC perm was not being mapped correctly for this case.

 The executable name was being checked as second time instead of using the
 requested onexec profile name, which may not be the same as the exec
 profile name. This mistake can not be exploited to grant extra permission
 because of the above flaw where the ONEXEC permission was not being mapped
 so it will not be granted.

BugLink: http://bugs.launchpad.net/bugs/963756

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-03-28 01:00:05 +11:00