Commit Graph

272 Commits

Author SHA1 Message Date
Linus Torvalds
ff30564411 Merge tag 'apparmor-pr-2024-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
 "Cleanups
   - optimization: try to avoid refing the label in apparmor_file_open
   - remove useless static inline function is_deleted
   - use kvfree_sensitive to free data->data
   - fix typo in kernel doc

  Bug fixes:
   - unpack transition table if dfa is not present
   - test: add MODULE_DESCRIPTION()
   - take nosymfollow flag into account
   - fix possible NULL pointer dereference
   - fix null pointer deref when receiving skb during sock creation"

* tag 'apparmor-pr-2024-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: unpack transition table if dfa is not present
  apparmor: try to avoid refing the label in apparmor_file_open
  apparmor: test: add MODULE_DESCRIPTION()
  apparmor: take nosymfollow flag into account
  apparmor: fix possible NULL pointer dereference
  apparmor: fix typo in kernel doc
  apparmor: remove useless static inline function is_deleted
  apparmor: use kvfree_sensitive to free data->data
  apparmor: Fix null pointer deref when receiving skb during sock creation
2024-07-27 13:28:39 -07:00
Mateusz Guzik
f4fee216df apparmor: try to avoid refing the label in apparmor_file_open
If the label is not stale (which is the common case), the fact that the
passed file object holds a reference can be leverged to avoid the
ref/unref cycle. Doing so reduces performance impact of apparmor on
parallel open() invocations.

When benchmarking on a 24-core vm using will-it-scale's open1_process
("Separate file open"), the results are (ops/s):
before: 6092196
after:  8309726 (+36%)

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2024-07-24 11:05:14 -07:00
GUO Zihua
9a95c5bfbf ima: Avoid blocking in RCU read-side critical section
A panic happens in ima_match_policy:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
               BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
      7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
      f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
      44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS:  00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ima_get_action+0x22/0x30
 process_measurement+0xb0/0x830
 ? page_add_file_rmap+0x15/0x170
 ? alloc_set_pte+0x269/0x4c0
 ? prep_new_page+0x81/0x140
 ? simple_xattr_get+0x75/0xa0
 ? selinux_file_open+0x9d/0xf0
 ima_file_check+0x64/0x90
 path_openat+0x571/0x1720
 do_filp_open+0x9b/0x110
 ? page_counter_try_charge+0x57/0xc0
 ? files_cgroup_alloc_fd+0x38/0x60
 ? __alloc_fd+0xd4/0x250
 ? do_sys_open+0x1bd/0x250
 do_sys_open+0x1bd/0x250
 do_syscall_64+0x5d/0x1d0
 entry_SYSCALL_64_after_hwframe+0x65/0xca

Commit c7423dbdbc ("ima: Handle -ESTALE returned by
ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.

Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.

The root cause of this issue could be described as follows:
|	Thread A	|	Thread B	|
|			|ima_match_policy	|
|			|  rcu_read_lock	|
|ima_lsm_update_rule	|			|
|  synchronize_rcu	|			|
|			|    kmalloc(GFP_KERNEL)|
|			|      sleep		|
==> synchronize_rcu returns early
|  kfree(entry)		|			|
|			|    entry = entry->next|
==> UAF happens and entry now becomes NULL (or could be anything).
|			|    entry->action	|
==> Accessing entry might cause panic.

To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.

Fixes: c7423dbdbc ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Cc: stable@vger.kernel.org
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-06-13 14:26:50 -04:00
Casey Schaufler
223981db9b AppArmor: Add selfattr hooks
Add hooks for setselfattr and getselfattr. These hooks are not very
different from their setprocattr and getprocattr equivalents, and
much of the code is shared.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
[PM: forward ported beyond v6.6 due merge window changes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-11-12 22:54:42 -05:00
John Johansen
157a3537d6 apparmor: Fix regression in mount mediation
commit 2db154b3ea ("vfs: syscall: Add move_mount(2) to move mounts around")

introduced a new move_mount(2) system call and a corresponding new LSM
security_move_mount hook but did not implement this hook for any
existing LSM. This creates a regression for AppArmor mediation of
mount. This patch provides a base mapping of the move_mount syscall to
the existing mount mediation. In the future we may introduce
additional mediations around the new mount calls.

Fixes: 2db154b3ea ("vfs: syscall: Add move_mount(2) to move mounts around")
CC: stable@vger.kernel.org
Reported-by: Andreas Steinmetz <anstein99@googlemail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 16:01:32 -07:00
Georgia Garcia
c4371d9063 apparmor: add io_uring mediation
For now, the io_uring mediation is limited to sqpoll and
override_creds.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:58:49 -07:00
John Johansen
fa9b63adab apparmor: add user namespace creation mediation
Unprivileged user namespace creation is often used as a first step
in privilege escalation attacks. Instead of disabling it at the
sysrq level, which blocks its legitimate use as for setting up a sandbox,
allow control on a per domain basis.

This allows an admin to quickly lock down a system while also still
allowing legitimate use.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:49:02 -07:00
John Johansen
2d9da9b188 apparmor: allow restricting unprivileged change_profile
unprivileged unconfined can use change_profile to alter the confinement
set by the mac admin.

Allow restricting unprivileged unconfined by still allowing change_profile
but stacking the change against unconfined. This allows unconfined to
still apply system policy but allows the task to enter the new confinement.

If unprivileged unconfined is required a sysctl is provided to switch
to the previous behavior.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:48:44 -07:00
John Johansen
98b824ff89 apparmor: refcount the pdb
With the move to permission tables the dfa is no longer a stand
alone entity when used, needing a minimum of a permission table.
However it still could be shared among different pdbs each using
a different permission table.

Instead of duping the permission table when sharing a pdb, add a
refcount to the pdb so it can be easily shared.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:30:47 -07:00
John Johansen
90c436a64a apparmor: pass cred through to audit info.
The cred is needed to properly audit some messages, and will be needed
in the future for uid conditional mediation. So pass it through to
where the apparmor_audit_data struct gets defined.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:30:38 -07:00
John Johansen
d20f5a1a6e apparmor: rename audit_data->label to audit_data->subj_label
rename audit_data's label field to subj_label to better reflect its
use. Also at the same time drop unneeded assignments to ->subj_label
as the later call to aa_check_perms will do the assignment if needed.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:30:34 -07:00
John Johansen
bd7bd201ca apparmor: combine common_audit_data and apparmor_audit_data
Everywhere where common_audit_data is used apparmor audit_data is also
used. We can simplify the code and drop the use of the aad macro
everywhere by combining the two structures.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:30:29 -07:00
John Johansen
79ddd4a7c5 apparmor: rename SK_CTX() to aa_sock and make it an inline fn
In preparation for LSM stacking rework the macro to an inline fn

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:29:55 -07:00
Xiu Jianfeng
fee5304a9c apparmor: remove unused functions in policy_ns.c/.h
These functions are not used now, remove them.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-15 21:44:31 -07:00
GONG, Ruiqi
efea5b0dcc apparmor: remove unused PROF_* macros
The last usage of PROF_{ADD,REPLACE} were removed by commit 18e99f191a
("apparmor: provide finer control over policy management"). So remove
these two unused macros.

Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-08-08 13:24:48 -07:00
Xiu Jianfeng
980a580868 apparmor: cleanup unused functions in file.h
After changes in commit 33bf60cabc ("LSM: Infrastructure management of
the file security"), aa_alloc_file_ctx() and aa_free_file_ctx() are no
longer used, so remove them, and also remove aa_get_file_label() because
it seems that it's never been used before.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-08-08 13:16:13 -07:00
Xiu Jianfeng
9a0dbdbff0 apparmor: cleanup unused declarations in policy.h
The implementions of these declarations do not exist, remove them all.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-08-08 13:15:39 -07:00
GONG, Ruiqi
8de4a7de19 apparmor: remove unused macro
SOCK_ctx() doesn't seem to be used anywhere in the code, so remove it.

Signed-off-by: GONG, Ruiqi <gongruiqi@huaweicloud.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-09 17:31:11 -07:00
Quanfa Fu
0897fcb1c1 apparmor: make aa_set_current_onexec return void
Change the return type to void since it always return 0, and no need
to do the checking in aa_set_current_onexec.

Signed-off-by: Quanfa Fu <quanfafu@gmail.com>
Reviewed-by: "Tyler Hicks (Microsoft)" <code@tyhicks.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-09 17:30:51 -07:00
Peter Zijlstra
9a1f37ebcf apparmor: Free up __cleanup() name
In order to use __cleanup for __attribute__((__cleanup__(func))) the
name must not be used for anything else. Avoid the conflict.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Link: https://lkml.kernel.org/r/20230612093537.536441207%40infradead.org
2023-06-26 11:14:18 +02:00
Linus Torvalds
93761c93e9 Merge tag 'apparmor-pr-2022-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
 "Features:
   - switch to zstd compression for profile raw data

  Cleanups:
   - simplify obtaining the newest label on a cred
   - remove useless static inline functions
   - compute permission conversion on policy unpack
   - refactor code to share common permissins
   - refactor unpack to group policy backwards compatiblity code
   - add __init annotation to aa_{setup/teardown}_dfa_engine()

  Bug Fixes:
   - fix a memleak in
       - multi_transaction_new()
       - free_ruleset()
       - unpack_profile()
       - alloc_ns()
   - fix lockdep warning when removing a namespace
   - fix regression in stacking due to label flags
   - fix loading of child before parent
   - fix kernel-doc comments that differ from fns
   - fix spelling errors in comments
   - store return value of unpack_perms_table() to signed variable"

* tag 'apparmor-pr-2022-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: (64 commits)
  apparmor: Fix uninitialized symbol 'array_size' in policy_unpack_test.c
  apparmor: Add __init annotation to aa_{setup/teardown}_dfa_engine()
  apparmor: Fix memleak in alloc_ns()
  apparmor: Fix memleak issue in unpack_profile()
  apparmor: fix a memleak in free_ruleset()
  apparmor: Fix spelling of function name in comment block
  apparmor: Use pointer to struct aa_label for lbs_cred
  AppArmor: Fix kernel-doc
  LSM: Fix kernel-doc
  AppArmor: Fix kernel-doc
  apparmor: Fix loading of child before parent
  apparmor: refactor code that alloc null profiles
  apparmor: fix obsoleted comments for aa_getprocattr() and audit_resource()
  apparmor: remove useless static inline functions
  apparmor: Fix unpack_profile() warn: passing zero to 'ERR_PTR'
  apparmor: fix uninitialize table variable in error in unpack_trans_table
  apparmor: store return value of unpack_perms_table() to signed variable
  apparmor: Fix kunit test for out of bounds array
  apparmor: Fix decompression of rawdata for read back to userspace
  apparmor: Fix undefined references to zstd_ symbols
  ...
2022-12-14 13:42:09 -08:00
Rae Moar
b11e51dd70 apparmor: test: make static symbols visible during kunit testing
Use macros, VISIBLE_IF_KUNIT and EXPORT_SYMBOL_IF_KUNIT, to allow
static symbols to be conditionally set to be visible during
apparmor_policy_unpack_test, which removes the need to include the testing
file in the implementation file.

Change the namespace of the symbols that are now conditionally visible (by
adding the prefix aa_) to avoid confusion with symbols of the same name.

Allow the test to be built as a module and namespace the module name from
policy_unpack_test to apparmor_policy_unpack_test to improve clarity of
the module name.

Provide an example of how static symbols can be dealt with in testing.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-12-12 14:13:48 -07:00
John Johansen
58f89ce58b apparmor: refactor code that alloc null profiles
Bother unconfined and learning profiles use the null profile as their
base. Refactor so they are share a common base routine. This doesn't
save much atm but will be important when the feature set of the
parent is inherited.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-10-24 22:35:36 -07:00
John Johansen
70f24a9f90 apparmor: Fix undefined references to zstd_ symbols
Unfortunately the switch to using zstd compression did not properly
ifdef all the code that uses zstd_ symbols. So that if exporting of
binary policy is disabled in the config the compile will fail with the
following errors

security/apparmor/lsm.c:1545: undefined reference to `zstd_min_clevel'
aarch64-linux-ld: security/apparmor/lsm.c:1545: undefined reference to `zstd_max_clevel'

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 52ccc20c652b ("apparmor: use zstd compression for profile data")
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Jon Tourville <jon.tourville@canonical.com>
2022-10-03 14:49:04 -07:00
Xiu Jianfeng
65f7f666f2 apparmor: make __aa_path_perm() static
Make __aa_path_perm() static as it's only used inside apparmor/file.c.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-10-03 14:49:04 -07:00