Commit Graph

18 Commits

Author SHA1 Message Date
John Johansen f567e7fada apparmor: extend policydb permission set by making use of the xbits
The policydb permission set has left the xbits unused. Make them available
for mediation.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-07-19 02:57:15 -07:00
Xin Xiong 11c3627ec6 apparmor: fix reference count leak in aa_pivotroot()
The aa_pivotroot() function has a reference counting bug in a specific
path. When aa_replace_current_label() returns on success, the function
forgets to decrement the reference count of “target”, which is
increased earlier by build_pivotroot(), causing a reference leak.

Fix it by decreasing the refcount of “target” in that path.

Fixes: 2ea3ffb778 ("apparmor: add mount mediation")
Co-developed-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Co-developed-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-07-09 15:13:59 -07:00
Yang Li e21851b349 apparmor: Fix match_mnt_path_str() and match_mnt() kernel-doc comment
Fix a spelling problem and change @mntpath to @path to remove warnings
found by running scripts/kernel-doc, which is caused by using 'make W=1'.

security/apparmor/mount.c:321: warning: Function parameter or member
'devname' not described in 'match_mnt_path_str'
security/apparmor/mount.c:321: warning: Excess function parameter
'devnme' description in 'match_mnt_path_str'
security/apparmor/mount.c:377: warning: Function parameter or member
'path' not described in 'match_mnt'
security/apparmor/mount.c:377: warning: Excess function parameter
'mntpath' description in 'match_mnt'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-07-09 15:13:59 -07:00
John Johansen ec240b5905 apparmor: Fix failed mount permission check error message
When the mount check fails due to a permission check failure instead
of explicitly at one of the subcomponent checks, AppArmor is reporting
a failure in the flags match. However this is not true and AppArmor
can not attribute the error at this point to any particular component,
and should only indicate the mount failed due to missing permissions.

Fixes: 2ea3ffb778 ("apparmor: add mount mediation")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-07-09 15:13:59 -07:00
Al Viro 64b2f34f38 apparmor:match_mn() - constify devpath argument
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-03-24 14:11:29 -04:00
Patrick Steinhardt 9c95a278ba apparmor: fix bind mounts aborting with -ENOMEM
With commit df323337e5 ("apparmor: Use a memory pool instead per-CPU
caches, 2019-05-03"), AppArmor code was converted to use memory pools. In
that conversion, a bug snuck into the code that polices bind mounts that
causes all bind mounts to fail with -ENOMEM, as we erroneously error out
if `aa_get_buffer` returns a pointer instead of erroring out when it
does _not_ return a valid pointer.

Fix the issue by correctly checking for valid pointers returned by
`aa_get_buffer` to fix bind mounts with AppArmor.

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-02 05:31:40 -08:00
Linus Torvalds 79e178a57d + Features
- increase left match history buffer size to provide inproved conflict
     resolution in overlapping execution rules.
   - switch buffer allocation to use a memory pool and GFP_KERNEL
     where possible.
   - add compression of policy blobs to reduce memory usage.
 + Cleanups
   - fix spelling mistake "immutible" -> "immutable"
 + Bug fixes
   - fix unsigned len comparison in update_for_len macro
   - fix sparse warning for type-casting of current->real_cred
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Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features:

   - increase left match history buffer size to provide improved
     conflict resolution in overlapping execution rules.

   - switch buffer allocation to use a memory pool and GFP_KERNEL where
     possible.

   - add compression of policy blobs to reduce memory usage.

  Cleanups:

   - fix spelling mistake "immutible" -> "immutable"

  Bug fixes:

   - fix unsigned len comparison in update_for_len macro

   - fix sparse warning for type-casting of current->real_cred"

* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: make it so work buffers can be allocated from atomic context
  apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
  apparmor: fix wrong buffer allocation in aa_new_mount
  apparmor: fix unsigned len comparison with less than zero
  apparmor: increase left match history buffer size
  apparmor: Switch to GFP_KERNEL where possible
  apparmor: Use a memory pool instead per-CPU caches
  apparmor: Force type-casting of current->real_cred
  apparmor: fix spelling mistake "immutible" -> "immutable"
  apparmor: fix blob compression when ns is forced on a policy load
  apparmor: fix missing ZLIB defines
  apparmor: fix blob compression build failure on ppc
  apparmor: Initial implementation of raw policy blob compression
2019-12-03 12:51:35 -08:00
John Johansen 341c1fda5e apparmor: make it so work buffers can be allocated from atomic context
In some situations AppArmor needs to be able to use its work buffers
from atomic context. Add the ability to specify when in atomic context
and hold a set of work buffers in reserve for atomic context to
reduce the chance that a large work buffer allocation will need to
be done.

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-22 16:41:08 -08:00
John Johansen 8f21a62475 apparmor: fix wrong buffer allocation in aa_new_mount
Fix the following trace caused by the dev_path buffer not being
allocated.

[  641.044262] AppArmor WARN match_mnt: ((devpath && !devbuffer)):
[  641.044284] WARNING: CPU: 1 PID: 30709 at ../security/apparmor/mount.c:385 match_mnt+0x133/0x180
[  641.044286] Modules linked in: snd_hda_codec_generic ledtrig_audio snd_hda_intel snd_hda_codec snd_hda_core qxl ttm snd_hwdep snd_pcm drm_kms_helper snd_seq_midi snd_seq_midi_event drm snd_rawmidi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel iptable_mangle aesni_intel aes_x86_64 xt_tcpudp crypto_simd snd_seq cryptd bridge stp llc iptable_filter glue_helper snd_seq_device snd_timer joydev input_leds snd serio_raw fb_sys_fops 9pnet_virtio 9pnet syscopyarea sysfillrect soundcore sysimgblt qemu_fw_cfg mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 8139too psmouse 8139cp i2c_piix4 pata_acpi mii floppy
[  641.044318] CPU: 1 PID: 30709 Comm: mount Tainted: G      D W         5.1.0-rc4+ #223
[  641.044320] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  641.044323] RIP: 0010:match_mnt+0x133/0x180
[  641.044325] Code: 41 5d 41 5e 41 5f c3 48 8b 4c 24 18 eb b1 48 c7 c6 08 84 26 83 48 c7 c7 f0 56 54 83 4c 89 54 24 08 48 89 14 24 e8 7d d3 bb ff <0f> 0b 4c 8b 54 24 08 48 8b 14 24 e9 25 ff ff ff 48 c7 c6 08 84 26
[  641.044327] RSP: 0018:ffffa9b34ac97d08 EFLAGS: 00010282
[  641.044329] RAX: 0000000000000000 RBX: ffff9a86725a8558 RCX: 0000000000000000
[  641.044331] RDX: 0000000000000002 RSI: 0000000000000001 RDI: 0000000000000246
[  641.044333] RBP: ffffa9b34ac97db0 R08: 0000000000000000 R09: 0000000000000000
[  641.044334] R10: 0000000000000000 R11: 00000000000077f5 R12: 0000000000000000
[  641.044336] R13: ffffa9b34ac97e98 R14: ffff9a865e000008 R15: ffff9a86c4cf42b8
[  641.044338] FS:  00007fab73969740(0000) GS:ffff9a86fbb00000(0000) knlGS:0000000000000000
[  641.044340] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  641.044342] CR2: 000055f90bc62035 CR3: 00000000aab5f006 CR4: 00000000003606e0
[  641.044346] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  641.044348] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  641.044349] Call Trace:
[  641.044355]  aa_new_mount+0x119/0x2c0
[  641.044363]  apparmor_sb_mount+0xd4/0x430
[  641.044367]  security_sb_mount+0x46/0x70
[  641.044372]  do_mount+0xbb/0xeb0
[  641.044377]  ? memdup_user+0x4b/0x70
[  641.044380]  ksys_mount+0x7e/0xd0
[  641.044384]  __x64_sys_mount+0x21/0x30
[  641.044388]  do_syscall_64+0x5a/0x1a0
[  641.044392]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  641.044394] RIP: 0033:0x7fab73a8790a
[  641.044397] Code: 48 8b 0d 89 85 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 56 85 0c 00 f7 d8 64 89 01 48
[  641.044399] RSP: 002b:00007ffe0ffe4238 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[  641.044401] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fab73a8790a
[  641.044429] RDX: 000055f90bc6203b RSI: 00007ffe0ffe57b1 RDI: 00007ffe0ffe57a5
[  641.044431] RBP: 00007ffe0ffe4250 R08: 0000000000000000 R09: 00007fab73b51d80
[  641.044433] R10: 00000000c0ed0004 R11: 0000000000000206 R12: 000055f90bc610b0
[  641.044434] R13: 00007ffe0ffe4330 R14: 0000000000000000 R15: 0000000000000000
[  641.044457] irq event stamp: 0
[  641.044460] hardirqs last  enabled at (0): [<0000000000000000>]           (null)
[  641.044463] hardirqs last disabled at (0): [<ffffffff82290114>] copy_process.part.30+0x734/0x23f0
[  641.044467] softirqs last  enabled at (0): [<ffffffff82290114>] copy_process.part.30+0x734/0x23f0
[  641.044469] softirqs last disabled at (0): [<0000000000000000>]           (null)
[  641.044470] ---[ end trace c0d54bdacf6af6b2 ]---

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-22 16:39:32 -08:00
Sebastian Andrzej Siewior 8ac2ca328e apparmor: Switch to GFP_KERNEL where possible
After removing preempt_disable() from get_buffers() it is possible to
replace a few GFP_ATOMIC allocations with GFP_KERNEL.

Replace GFP_ATOMIC allocations with GFP_KERNEL where the context looks
to bee preepmtible.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-06-20 10:33:31 -07:00
Sebastian Andrzej Siewior df323337e5 apparmor: Use a memory pool instead per-CPU caches
The get_buffers() macro may provide one or two buffers to the caller.
Those buffers are pre-allocated on init for each CPU. By default it
allocates
	2* 2 * MAX_PATH * POSSIBLE_CPU

which equals 64KiB on a system with 4 CPUs or 1MiB with 64 CPUs and so
on.

Replace the per-CPU buffers with a common memory pool which is shared
across all CPUs. The pool grows on demand and never shrinks. The pool
starts with two (UP) or four (SMP) elements. By using this pool it is
possible to request a buffer and keeping preemption enabled which avoids
the hack in profile_transition().

It has been pointed out by Tetsuo Handa that GFP_KERNEL allocations for
small amount of memory do not fail. In order not to have an endless
retry, __GFP_RETRY_MAYFAIL is passed (so the memory allocation is not
repeated until success) and retried once hoping that in the meantime a
buffer has been returned to the pool. Since now NULL is possible all
allocation paths check the buffer pointer and return -ENOMEM on failure.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-06-20 10:33:31 -07:00
Thomas Gleixner b886d83c5b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:17 +02:00
David Howells e262e32d6b vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled
Only the mount namespace code that implements mount(2) should be using the
MS_* flags.  Suppress them inside the kernel unless uapi/linux/mount.h is
included.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Howells <dhowells@redhat.com>
2018-12-20 16:32:56 +00:00
Zygmunt Krynicki 68a1a0c68c apparmor: fix typo "independent"
Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-05-03 00:50:30 -07:00
John Johansen d8889d49e4 apparmor: move context.h to cred.h
Now that file contexts have been moved into file, and task context
fns() and data have been split from the context, only the cred context
remains in context.h so rename to cred.h to better reflect what it
deals with.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen 5b9f57cf47 apparmor: fix regression in mount mediation when feature set is pinned
When the mount code was refactored for Labels it was not correctly
updated to check whether policy supported mediation of the mount
class.  This causes a regression when the kernel feature set is
reported as supporting mount and policy is pinned to a feature set
that does not support mount mediation.

BugLink: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=882697#41
Fixes: 2ea3ffb778 ("apparmor: add mount mediation")
Reported-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-01-05 15:07:42 -08:00
Arnd Bergmann 7bba39ae52 apparmor: initialized returned struct aa_perms
gcc-4.4 points out suspicious code in compute_mnt_perms, where
the aa_perms structure is only partially initialized before getting
returned:

security/apparmor/mount.c: In function 'compute_mnt_perms':
security/apparmor/mount.c:227: error: 'perms.prompt' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.hide' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.cond' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.complain' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.stop' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.deny' is used uninitialized in this function

Returning or assigning partially initialized structures is a bit tricky,
in particular it is explicitly allowed in c99 to assign a partially
initialized structure to another, as long as only members are read that
have been initialized earlier. Looking at what various compilers do here,
the version that produced the warning copied uninitialized stack data,
while newer versions (and also clang) either set the other members to
zero or don't update the parts of the return buffer that are not modified
in the temporary structure, but they never warn about this.

In case of apparmor, it seems better to be a little safer and always
initialize the aa_perms structure. Most users already do that, this
changes the remaining ones, including the one instance that I got the
warning for.

Fixes: fa488437d0f9 ("apparmor: add mount mediation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-11-21 02:15:50 -08:00
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