Commit Graph

267 Commits

Author SHA1 Message Date
Dmitry Kasatkin
e4a9c51965 ima: add missing '__init' keywords
Add missing keywords to the function definition to cleanup
to discard initialization code.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Reviewed-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09 10:28:50 -04:00
Dmitry Kasatkin
3a8a2eadc4 ima: remove unnecessary extra variable
'function' variable value can be changed instead of
allocating extra '_func' variable.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09 10:28:48 -04:00
Dmitry Kasatkin
f68c05f4d2 ima: simplify conditional statement to improve performance
Precede bit testing before string comparison makes code
faster. Also refactor statement as a single line pointer
assignment. Logic is following: we set 'xattr_ptr' to read
xattr value when we will do appraisal or in any case when
measurement template is other than 'ima'.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09 10:28:47 -04:00
Dmitry Kasatkin
65d98f3be2 integrity: remove declaration of non-existing functions
Commit f381c27 "integrity: move ima inode integrity data management"
(re)moved few functions but left their declarations in header files.
This patch removes them and also removes duplicated declaration of
integrity_iint_find().

Commit c7de7ad "ima: remove unused cleanup functions".  This patch
removes these definitions as well.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09 10:28:46 -04:00
Dmitry Kasatkin
d9a2e5d788 integrity: prevent flooding with 'Request for unknown key'
If file has IMA signature, IMA in enforce mode, but key is missing
then file access is blocked and single error message is printed.

If IMA appraisal is enabled in fix mode, then system runs as usual
but might produce tons of 'Request for unknown key' messages.

This patch switches 'pr_warn' to 'pr_err_ratelimited'.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09 10:28:44 -04:00
Dmitry Kasatkin
3034a14682 ima: pass 'opened' flag to identify newly created files
Empty files and missing xattrs do not guarantee that a file was
just created.  This patch passes FILE_CREATED flag to IMA to
reliably identify new files.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>  3.14+
2014-09-09 10:28:43 -04:00
Dmitry Kasatkin
3dcbad52cf evm: properly handle INTEGRITY_NOXATTRS EVM status
Unless an LSM labels a file during d_instantiate(), newly created
files are not labeled with an initial security.evm xattr, until
the file closes.  EVM, before allowing a protected, security xattr
to be written, verifies the existing 'security.evm' value is good.
For newly created files without a security.evm label, this
verification prevents writing any protected, security xattrs,
until the file closes.

Following is the example when this happens:
fd = open("foo", O_CREAT | O_WRONLY, 0644);
setxattr("foo", "security.SMACK64", value, sizeof(value), 0);
close(fd);

While INTEGRITY_NOXATTRS status is handled in other places, such
as evm_inode_setattr(), it does not handle it in all cases in
evm_protect_xattr().  By limiting the use of INTEGRITY_NOXATTRS to
newly created files, we can now allow setting "protected" xattrs.

Changelog:
- limit the use of INTEGRITY_NOXATTRS to IMA identified new files

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>  3.14+
2014-09-09 10:26:10 -04:00
Dmitry Kasatkin
b151d6b00b ima: provide flag to identify new empty files
On ima_file_free(), newly created empty files are not labeled with
an initial security.ima value, because the iversion did not change.
Commit dff6efc "fs: fix iversion handling" introduced a change in
iversion behavior.  To verify this change use the shell command:

  $ (exec >foo)
  $ getfattr -h -e hex -d -m security foo

This patch defines the IMA_NEW_FILE flag.  The flag is initially
set, when IMA detects that a new file is created, and subsequently
checked on the ima_file_free() hook to set the initial security.ima
value.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>  3.14+
2014-09-08 17:38:57 -04:00
Dmitry Kasatkin
1f1009791b evm: prevent passing integrity check if xattr read fails
This patch fixes a bug, where evm_verify_hmac() returns INTEGRITY_PASS
if inode->i_op->getxattr() returns an error in evm_find_protected_xattrs.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-09-08 17:36:10 -04:00
Dmitry Kasatkin
e7d021e283 evm: fix checkpatch warnings
This patch fixes checkpatch 'return' warnings introduced with commit
9819cf2 "checkpatch: warn on unnecessary void function return statements".

Use scripts/checkpatch.pl --file security/integrity/evm/evm_main.c
to produce the warnings.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-02 17:03:37 -04:00
Dmitry Kasatkin
27cd1fc3ae ima: fix fallback to use new_sync_read()
3.16 commit aad4f8bb42
'switch simple generic_file_aio_read() users to ->read_iter()'
replaced ->aio_read with ->read_iter in most of the file systems
and introduced new_sync_read() as a replacement for do_sync_read().

Most of file systems set '->read' and ima_kernel_read is not affected.
When ->read is not set, this patch adopts fallback call changes from the
vfs_read.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>  3.16+
2014-09-02 17:03:36 -04:00
Dmitry Kasatkin
23c19e2ca7 ima: prevent buffer overflow in ima_alloc_tfm()
This patch fixes the case where the file's signature/hash xattr contains
an invalid hash algorithm.  Although we can not verify the xattr, we still
need to measure the file.  Use the default IMA hash algorithm.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-02 17:03:36 -04:00
Mimi Zohar
9a8d289fbc ima: fix ima_alloc_atfm()
The patch 3bcced39ea: "ima: use ahash API for file hash
calculation" from Feb 26, 2014, leads to the following static checker
warning:

security/integrity/ima/ima_crypto.c:204 ima_alloc_atfm()
         error: buffer overflow 'hash_algo_name' 17 <= 17

Unlike shash tfm memory, which is allocated on initialization, the
ahash tfm memory allocation is deferred until needed.

This patch fixes the case where ima_ahash_tfm has not yet been
allocated and the file's signature/hash xattr contains an invalid hash
algorithm.  Although we can not verify the xattr, we still need to
measure the file.  Use the default IMA hash algorithm.

Changelog:
- set valid algo before testing tfm - based on Dmitry's comment

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-09-02 17:03:35 -04:00
Mimi Zohar
5a9196d715 ima: add support for measuring and appraising firmware
The "security: introduce kernel_fw_from_file hook" patch defined a
new security hook to evaluate any loaded firmware that wasn't built
into the kernel.

This patch defines ima_fw_from_file(), which is called from the new
security hook, to measure and/or appraise the loaded firmware's
integrity.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2014-07-25 11:47:46 -07:00
Mimi Zohar
7d2ce2320e ima: define '.ima' as a builtin 'trusted' keyring
Require all keys added to the IMA keyring be signed by an
existing trusted key on the system trusted keyring.

Changelog v6:
- remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry
- update Kconfig dependency and help
- select KEYS_DEBUG_PROC_KEYS - Dmitry

Changelog v5:
- Move integrity_init_keyring() to init_ima() - Dmitry
- reset keyring[id] on failure - Dmitry

Changelog v1:
- don't link IMA trusted keyring to user keyring

Changelog:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)
- only make the IMA keyring a trusted keyring (reported-by D. Kastatkin)
- define stub integrity_init_keyring() definition based on
  CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS.
  (reported-by Jim Davis)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: David Howells <dhowells@redhat.com>
2014-07-17 09:35:17 -04:00
Dmitry Kasatkin
32c2e6752f ima: provide double buffering for hash calculation
The asynchronous hash API allows initiating a hash calculation and
then performing other tasks, while waiting for the hash calculation
to complete.

This patch introduces usage of double buffering for simultaneous
hashing and reading of the next chunk of data from storage.

Changes in v3:
- better comments

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:11 -04:00
Dmitry Kasatkin
6edf7a8926 ima: introduce multi-page collect buffers
Use of multiple-page collect buffers reduces:
1) the number of block IO requests
2) the number of asynchronous hash update requests

Second is important for HW accelerated hashing, because significant
amount of time is spent for preparation of hash update operation,
which includes configuring acceleration HW, DMA engine, etc...
Thus, HW accelerators are more efficient when working on large
chunks of data.

This patch introduces usage of multi-page collect buffers. Buffer size
can be specified using 'ahash_bufsize' module parameter. Default buffer
size is 4096 bytes.

Changes in v3:
- kernel parameter replaced with module parameter

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:11 -04:00
Dmitry Kasatkin
3bcced39ea ima: use ahash API for file hash calculation
Async hash API allows the use of HW acceleration for hash calculation.
It may give significant performance gain and/or reduce power consumption,
which might be very beneficial for battery powered devices.

This patch introduces hash calculation using ahash API. ahash performance
depends on the data size and the particular HW. Depending on the specific
system, shash performance may be better.

This patch defines 'ahash_minsize' module parameter, which is used to
define the minimal file size to use with ahash.  If this minimum file size
is not set or the file is smaller than defined by the parameter, shash will
be used.

Changes in v3:
- kernel parameter replaced with module parameter
- pr_crit replaced with pr_crit_ratelimited
- more comment changes - Mimi

Changes in v2:
- ima_ahash_size became as ima_ahash
- ahash pre-allocation moved out from __init code to be able to use
  ahash crypto modules. Ahash allocated once on the first use.
- hash calculation falls back to shash if ahash allocation/calculation fails
- complex initialization separated from variable declaration
- improved comments

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:10 -04:00
Richard Guy Briggs
7e9001f663 audit: fix dangling keywords in integrity ima message output
Replace spaces in op keyword labels in log output since userspace audit tools
can't parse orphaned keywords.

Reported-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:10 -04:00
Dmitry Kasatkin
209b43ca64 ima: delay template descriptor lookup until use
process_measurement() always calls ima_template_desc_current(),
including when an IMA policy has not been defined.

This patch delays template descriptor lookup until action is
determined.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:09 -04:00
Dmitry Kasatkin
2c50b96482 ima: remove unnecessary i_mutex locking from ima_rdwr_violation_check()
Before 2.6.39 inode->i_readcount was maintained by IMA. It was not atomic
and protected using spinlock. For 2.6.39, i_readcount was converted to
atomic and maintaining was moved VFS layer. Spinlock for some unclear
reason was replaced by i_mutex.

After analyzing the code, we came to conclusion that i_mutex locking is
unnecessary, especially when an IMA policy has not been defined.

This patch removes i_mutex locking from ima_rdwr_violation_check().

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:09 -04:00
Dmitry Kasatkin
0430e49b6e ima: introduce ima_kernel_read()
Commit 8aac62706 "move exit_task_namespaces() outside of exit_notify"
introduced the kernel opps since the kernel v3.10, which happens when
Apparmor and IMA-appraisal are enabled at the same time.

----------------------------------------------------------------------
[  106.750167] BUG: unable to handle kernel NULL pointer dereference at
0000000000000018
[  106.750221] IP: [<ffffffff811ec7da>] our_mnt+0x1a/0x30
[  106.750241] PGD 0
[  106.750254] Oops: 0000 [#1] SMP
[  106.750272] Modules linked in: cuse parport_pc ppdev bnep rfcomm
bluetooth rpcsec_gss_krb5 nfsd auth_rpcgss nfs_acl nfs lockd sunrpc
fscache dm_crypt intel_rapl x86_pkg_temp_thermal intel_powerclamp
kvm_intel snd_hda_codec_hdmi kvm crct10dif_pclmul crc32_pclmul
ghash_clmulni_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul
ablk_helper cryptd snd_hda_codec_realtek dcdbas snd_hda_intel
snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_seq_midi
snd_seq_midi_event snd_rawmidi psmouse snd_seq microcode serio_raw
snd_timer snd_seq_device snd soundcore video lpc_ich coretemp mac_hid lp
parport mei_me mei nbd hid_generic e1000e usbhid ahci ptp hid libahci
pps_core
[  106.750658] CPU: 6 PID: 1394 Comm: mysqld Not tainted 3.13.0-rc7-kds+ #15
[  106.750673] Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A08
09/19/2012
[  106.750689] task: ffff8800de804920 ti: ffff880400fca000 task.ti:
ffff880400fca000
[  106.750704] RIP: 0010:[<ffffffff811ec7da>]  [<ffffffff811ec7da>]
our_mnt+0x1a/0x30
[  106.750725] RSP: 0018:ffff880400fcba60  EFLAGS: 00010286
[  106.750738] RAX: 0000000000000000 RBX: 0000000000000100 RCX:
ffff8800d51523e7
[  106.750764] RDX: ffffffffffffffea RSI: ffff880400fcba34 RDI:
ffff880402d20020
[  106.750791] RBP: ffff880400fcbae0 R08: 0000000000000000 R09:
0000000000000001
[  106.750817] R10: 0000000000000000 R11: 0000000000000001 R12:
ffff8800d5152300
[  106.750844] R13: ffff8803eb8df510 R14: ffff880400fcbb28 R15:
ffff8800d51523e7
[  106.750871] FS:  0000000000000000(0000) GS:ffff88040d200000(0000)
knlGS:0000000000000000
[  106.750910] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  106.750935] CR2: 0000000000000018 CR3: 0000000001c0e000 CR4:
00000000001407e0
[  106.750962] Stack:
[  106.750981]  ffffffff813434eb ffff880400fcbb20 ffff880400fcbb18
0000000000000000
[  106.751037]  ffff8800de804920 ffffffff8101b9b9 0001800000000000
0000000000000100
[  106.751093]  0000010000000000 0000000000000002 000000000000000e
ffff8803eb8df500
[  106.751149] Call Trace:
[  106.751172]  [<ffffffff813434eb>] ? aa_path_name+0x2ab/0x430
[  106.751199]  [<ffffffff8101b9b9>] ? sched_clock+0x9/0x10
[  106.751225]  [<ffffffff8134a68d>] aa_path_perm+0x7d/0x170
[  106.751250]  [<ffffffff8101b945>] ? native_sched_clock+0x15/0x80
[  106.751276]  [<ffffffff8134aa73>] aa_file_perm+0x33/0x40
[  106.751301]  [<ffffffff81348c5e>] common_file_perm+0x8e/0xb0
[  106.751327]  [<ffffffff81348d78>] apparmor_file_permission+0x18/0x20
[  106.751355]  [<ffffffff8130c853>] security_file_permission+0x23/0xa0
[  106.751382]  [<ffffffff811c77a2>] rw_verify_area+0x52/0xe0
[  106.751407]  [<ffffffff811c789d>] vfs_read+0x6d/0x170
[  106.751432]  [<ffffffff811cda31>] kernel_read+0x41/0x60
[  106.751457]  [<ffffffff8134fd45>] ima_calc_file_hash+0x225/0x280
[  106.751483]  [<ffffffff8134fb52>] ? ima_calc_file_hash+0x32/0x280
[  106.751509]  [<ffffffff8135022d>] ima_collect_measurement+0x9d/0x160
[  106.751536]  [<ffffffff810b552d>] ? trace_hardirqs_on+0xd/0x10
[  106.751562]  [<ffffffff8134f07c>] ? ima_file_free+0x6c/0xd0
[  106.751587]  [<ffffffff81352824>] ima_update_xattr+0x34/0x60
[  106.751612]  [<ffffffff8134f0d0>] ima_file_free+0xc0/0xd0
[  106.751637]  [<ffffffff811c9635>] __fput+0xd5/0x300
[  106.751662]  [<ffffffff811c98ae>] ____fput+0xe/0x10
[  106.751687]  [<ffffffff81086774>] task_work_run+0xc4/0xe0
[  106.751712]  [<ffffffff81066fad>] do_exit+0x2bd/0xa90
[  106.751738]  [<ffffffff8173c958>] ? retint_swapgs+0x13/0x1b
[  106.751763]  [<ffffffff8106780c>] do_group_exit+0x4c/0xc0
[  106.751788]  [<ffffffff81067894>] SyS_exit_group+0x14/0x20
[  106.751814]  [<ffffffff8174522d>] system_call_fastpath+0x1a/0x1f
[  106.751839] Code: c3 0f 1f 44 00 00 55 48 89 e5 e8 22 fe ff ff 5d c3
0f 1f 44 00 00 55 65 48 8b 04 25 c0 c9 00 00 48 8b 80 28 06 00 00 48 89
e5 5d <48> 8b 40 18 48 39 87 c0 00 00 00 0f 94 c0 c3 0f 1f 80 00 00 00
[  106.752185] RIP  [<ffffffff811ec7da>] our_mnt+0x1a/0x30
[  106.752214]  RSP <ffff880400fcba60>
[  106.752236] CR2: 0000000000000018
[  106.752258] ---[ end trace 3c520748b4732721 ]---
----------------------------------------------------------------------

The reason for the oops is that IMA-appraisal uses "kernel_read()" when
file is closed. kernel_read() honors LSM security hook which calls
Apparmor handler, which uses current->nsproxy->mnt_ns. The 'guilty'
commit changed the order of cleanup code so that nsproxy->mnt_ns was
not already available for Apparmor.

Discussion about the issue with Al Viro and Eric W. Biederman suggested
that kernel_read() is too high-level for IMA. Another issue, except
security checking, that was identified is mandatory locking. kernel_read
honors it as well and it might prevent IMA from calculating necessary hash.
It was suggested to use simplified version of the function without security
and locking checks.

This patch introduces special version ima_kernel_read(), which skips security
and mandatory locking checking. It prevents the kernel oops to happen.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
2014-06-12 17:58:08 -04:00
Mimi Zohar
2fb1c9a4f2 evm: prohibit userspace writing 'security.evm' HMAC value
Calculating the 'security.evm' HMAC value requires access to the
EVM encrypted key.  Only the kernel should have access to it.  This
patch prevents userspace tools(eg. setfattr, cp --preserve=xattr)
from setting/modifying the 'security.evm' HMAC value directly.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
2014-06-12 17:58:07 -04:00
Dmitry Kasatkin
14503eb994 ima: check inode integrity cache in violation check
When IMA did not support ima-appraisal, existance of the S_IMA flag
clearly indicated that the file was measured. With IMA appraisal S_IMA
flag indicates that file was measured and/or appraised. Because of
this, when measurement is not enabled by the policy, violations are
still reported.

To differentiate between measurement and appraisal policies this
patch checks the inode integrity cache flags.  The IMA_MEASURED
flag indicates whether the file was actually measured, while the
IMA_MEASURE flag indicates whether the file should be measured.
Unfortunately, the IMA_MEASURED flag is reset to indicate the file
needs to be re-measured.  Thus, this patch checks the IMA_MEASURE
flag.

This patch limits the false positive violation reports, but does
not fix it entirely.  The IMA_MEASURE/IMA_MEASURED flags are
indications that, at some point in time, the file opened for read
was in policy, but might not be in policy now (eg. different uid).
Other changes would be needed to further limit false positive
violation reports.

Changelog:
- expanded patch description based on conversation with Roberto (Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12 17:58:07 -04:00
Dmitry Kasatkin
b882fae2d3 ima: prevent unnecessary policy checking
ima_rdwr_violation_check is called for every file openning.
The function checks the policy even when violation condition
is not met. It causes unnecessary policy checking.

This patch does policy checking only if violation condition is met.

Changelog:
- check writecount is greater than zero (Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12 17:58:06 -04:00
Dmitry Kasatkin
3e38df56e6 evm: provide option to protect additional SMACK xattrs
Newer versions of SMACK introduced following security xattrs:
SMACK64EXEC, SMACK64TRANSMUTE and SMACK64MMAP.

To protect these xattrs, this patch includes them in the HMAC
calculation.  However, for backwards compatibility with existing
labeled filesystems, including these xattrs needs to be
configurable.

Changelog:
- Add SMACK dependency on new option (Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12 17:58:06 -04:00
Dmitry Kasatkin
d3b3367948 evm: replace HMAC version with attribute mask
Using HMAC version limits the posibility to arbitrarily add new
attributes such as SMACK64EXEC to the hmac calculation.

This patch replaces hmac version with attribute mask.
Desired attributes can be enabled with configuration parameter.
It allows to build kernels which works with previously labeled
filesystems.

Currently supported attribute is 'fsuuid' which is equivalent of
the former version 2.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12 17:58:06 -04:00
Mimi Zohar
060bdebfb0 ima: prevent new digsig xattr from being replaced
Even though a new xattr will only be appraised on the next access,
set the DIGSIG flag to prevent a signature from being replaced with
a hash on file close.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12 17:58:05 -04:00
Linus Torvalds
fad0701eaa Merge branch 'serge-next-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security
Pull security layer updates from Serge Hallyn:
 "This is a merge of James Morris' security-next tree from 3.14 to
  yesterday's master, plus four patches from Paul Moore which are in
  linux-next, plus one patch from Mimi"

* 'serge-next-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security:
  ima: audit log files opened with O_DIRECT flag
  selinux: conditionally reschedule in hashtab_insert while loading selinux policy
  selinux: conditionally reschedule in mls_convert_context while loading selinux policy
  selinux: reject setexeccon() on MNT_NOSUID applications with -EACCES
  selinux:  Report permissive mode in avc: denied messages.
  Warning in scanf string typing
  Smack: Label cgroup files for systemd
  Smack: Verify read access on file open - v3
  security: Convert use of typedef ctl_table to struct ctl_table
  Smack: bidirectional UDS connect check
  Smack: Correctly remove SMACK64TRANSMUTE attribute
  SMACK: Fix handling value==NULL in post setxattr
  bugfix patch for SMACK
  Smack: adds smackfs/ptrace interface
  Smack: unify all ptrace accesses in the smack
  Smack: fix the subject/object order in smack_ptrace_traceme()
  Minor improvement of 'smack_sb_kern_mount'
  smack: fix key permission verification
  KEYS: Move the flags representing required permission to linux/key.h
2014-06-10 10:05:36 -07:00
Mimi Zohar
f9b2a735bd ima: audit log files opened with O_DIRECT flag
Files are measured or appraised based on the IMA policy.  When a
file, in policy, is opened with the O_DIRECT flag, a deadlock
occurs.

The first attempt at resolving this lockdep temporarily removed the
O_DIRECT flag and restored it, after calculating the hash.  The
second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this
flag, do_blockdev_direct_IO() would skip taking the i_mutex a second
time.  The third attempt, by Dmitry Kasatkin, resolves the i_mutex
locking issue, by re-introducing the IMA mutex, but uncovered
another problem.  Reading a file with O_DIRECT flag set, writes
directly to userspace pages.  A second patch allocates a user-space
like memory.  This works for all IMA hooks, except ima_file_free(),
which is called on __fput() to recalculate the file hash.

Until this last issue is addressed, do not 'collect' the
measurement for measuring, appraising, or auditing files opened
with the O_DIRECT flag set.  Based on policy, permit or deny file
access.  This patch defines a new IMA policy rule option named
'permit_directio'.  Policy rules could be defined, based on LSM
or other criteria, to permit specific applications to open files
with the O_DIRECT flag set.

Changelog v1:
- permit or deny file access based IMA policy rules

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Cc: <stable@vger.kernel.org>
2014-06-03 14:21:50 -05:00
Linus Torvalds
5166701b36 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The first vfs pile, with deep apologies for being very late in this
  window.

  Assorted cleanups and fixes, plus a large preparatory part of iov_iter
  work.  There's a lot more of that, but it'll probably go into the next
  merge window - it *does* shape up nicely, removes a lot of
  boilerplate, gets rid of locking inconsistencie between aio_write and
  splice_write and I hope to get Kent's direct-io rewrite merged into
  the same queue, but some of the stuff after this point is having
  (mostly trivial) conflicts with the things already merged into
  mainline and with some I want more testing.

  This one passes LTP and xfstests without regressions, in addition to
  usual beating.  BTW, readahead02 in ltp syscalls testsuite has started
  giving failures since "mm/readahead.c: fix readahead failure for
  memoryless NUMA nodes and limit readahead pages" - might be a false
  positive, might be a real regression..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  kill generic_file_buffered_write()
  ocfs2_file_aio_write(): switch to generic_perform_write()
  ceph_aio_write(): switch to generic_perform_write()
  xfs_file_buffered_aio_write(): switch to generic_perform_write()
  export generic_perform_write(), start getting rid of generic_file_buffer_write()
  generic_file_direct_write(): get rid of ppos argument
  btrfs_file_aio_write(): get rid of ppos
  kill the 5th argument of generic_file_buffered_write()
  kill the 4th argument of __generic_file_aio_write()
  lustre: don't open-code kernel_recvmsg()
  ocfs2: don't open-code kernel_recvmsg()
  drbd: don't open-code kernel_recvmsg()
  constify blk_rq_map_user_iov() and friends
  lustre: switch to kernel_sendmsg()
  ocfs2: don't open-code kernel_sendmsg()
  take iov_iter stuff to mm/iov_iter.c
  process_vm_access: tidy up a bit
  ...
2014-04-12 14:49:50 -07:00
Linus Torvalds
0b747172dc Merge git://git.infradead.org/users/eparis/audit
Pull audit updates from Eric Paris.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
  audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
  audit: do not cast audit_rule_data pointers pointlesly
  AUDIT: Allow login in non-init namespaces
  audit: define audit_is_compat in kernel internal header
  kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
  sched: declare pid_alive as inline
  audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
  syscall_get_arch: remove useless function arguments
  audit: remove stray newline from audit_log_execve_info() audit_panic() call
  audit: remove stray newlines from audit_log_lost messages
  audit: include subject in login records
  audit: remove superfluous new- prefix in AUDIT_LOGIN messages
  audit: allow user processes to log from another PID namespace
  audit: anchor all pid references in the initial pid namespace
  audit: convert PPIDs to the inital PID namespace.
  pid: get pid_t ppid of task in init_pid_ns
  audit: rename the misleading audit_get_context() to audit_take_context()
  audit: Add generic compat syscall support
  audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
  ...
2014-04-12 12:38:53 -07:00
Al Viro
627bf81ac6 get rid of pointless checks for NULL ->i_op
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:16 -04:00
Richard Guy Briggs
f1dc4867ff audit: anchor all pid references in the initial pid namespace
Store and log all PIDs with reference to the initial PID namespace and
use the access functions task_pid_nr() and task_tgid_nr() for task->pid
and task->tgid.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
(informed by ebiederman's c776b5d2)
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
2014-03-20 10:11:55 -04:00
Dmitry Kasatkin
a3aef94b31 evm: enable key retention service automatically
If keys are not enabled, EVM is not visible in the configuration menu.
It may be difficult to figure out what to do unless you really know.
Other subsystems as NFS, CIFS select keys automatically. This patch does
the same.

This patch also removes '(TRUSTED_KEYS=y || TRUSTED_KEYS=n)' dependency,
which is unnecessary. EVM does not depend on trusted keys, but on
encrypted keys. evm.h provides compile time dependency.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:49 -05:00
Dmitry Kasatkin
1d91ac6213 ima: skip memory allocation for empty files
Memory allocation is unnecessary for empty files.
This patch calculates the hash without memory allocation.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:48 -05:00
Dmitry Kasatkin
e0420039b6 evm: EVM does not use MD5
EVM does not use MD5 HMAC. Selection of CRYPTO_MD5 can be safely removed.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:47 -05:00
Dmitry Kasatkin
61997c4383 ima: return d_name.name if d_path fails
This is a small refactoring so ima_d_path() returns dentry name
if path reconstruction fails. It simplifies callers actions
and removes code duplication.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:46 -05:00
Dmitry Kasatkin
2bb930abcf integrity: fix checkpatch errors
Between checkpatch changes (eg. sizeof) and inconsistencies between
Lindent and checkpatch, unfixed checkpatch errors make it difficult
to see new errors. This patch fixes them. Some lines with over 80 chars
remained unchanged to improve code readability.

The "extern" keyword is removed from internal evm.h to make it consistent
with internal ima.h.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:45 -05:00
Dmitry Kasatkin
09b1148ef5 ima: fix erroneous removal of security.ima xattr
ima_inode_post_setattr() calls ima_must_appraise() to check if the
file needs to be appraised. If it does not then it removes security.ima
xattr. With original policy matching code it might happen that even
file needs to be appraised with FILE_CHECK hook, it might not be
for POST_SETATTR hook. 'security.ima' might be erronously removed.

This patch treats POST_SETATTR as special wildcard function and will
cause ima_must_appraise() to be true if any of the hooks rules matches.
security.ima will not be removed if any of the hooks would require
appraisal.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:44 -05:00
Joe Perches
20ee451f5a security: integrity: Use a more current logging style
Convert printks to pr_<level>.
Add pr_fmt.
Remove embedded prefixes.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 12:15:21 -05:00
Roberto Sassu
e3b64c268b ima: reduce memory usage when a template containing the n field is used
Before this change, to correctly calculate the template digest for the
'ima' template, the event name field (id: 'n') length was set to the fixed
size of 256 bytes.

This patch reduces the length of the event name field to the string
length incremented of one (to make room for the termination character '\0')
and handles the specific case of the digest calculation for the 'ima'
template directly in ima_calc_field_array_hash_tfm().

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 11:32:30 -05:00
Roberto Sassu
c019e307ad ima: restore the original behavior for sending data with ima template
With the new template mechanism introduced in IMA since kernel 3.13,
the format of data sent through the binary_runtime_measurements interface
is slightly changed. Now, for a generic measurement, the format of
template data (after the template name) is:

template_len | field1_len | field1 | ... | fieldN_len | fieldN

In addition, fields containing a string now include the '\0' termination
character.

Instead, the format for the 'ima' template should be:

SHA1 digest | event name length | event name

It must be noted that while in the IMA 3.13 code 'event name length' is
'IMA_EVENT_NAME_LEN_MAX + 1' (256 bytes), so that the template digest
is calculated correctly, and 'event name' contains '\0', in the pre 3.13
code 'event name length' is exactly the string length and 'event name'
does not contain the termination character.

The patch restores the behavior of the IMA code pre 3.13 for the 'ima'
template so that legacy userspace tools obtain a consistent behavior
when receiving data from the binary_runtime_measurements interface
regardless of which kernel version is used.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: <stable@vger.kernel.org> # 3.3.13: 3ce1217 ima: define template fields library
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 11:32:29 -05:00
Tetsuo Handa
73a6b44a00 Integrity: Pass commname via get_task_comm()
When we pass task->comm to audit_log_untrustedstring(), we need to pass it
via get_task_comm() because task->comm can be changed to contain untrusted
string by other threads after audit_log_untrustedstring() confirmed that
task->comm does not contain untrusted string.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07 11:32:28 -05:00
Mimi Zohar
52a1328484 ima: use static const char array definitions
A const char pointer allocates memory for a pointer as well as for
a string,  This patch replaces a number of the const char pointers
throughout IMA, with a static const char array.

Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
2014-03-07 11:30:36 -05:00
Libo Chen
31d4b76189 ima: new helper: file_inode(file)
Replace "file->f_dentry->d_inode" with the new file_inode() helper
function.

Signed-off-by: Libo Chen <clbchenlibo.chen@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-04 16:53:03 -05:00
Sam Ravnborg
e0c2de2b15 security: cleanup Makefiles to use standard syntax for specifying sub-directories
The Makefiles in security/ uses a non-standard way to
specify sub-directories for building.

Fix it up so the normal (and documented) approach is used.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-02-17 11:08:04 +11:00
Jingoo Han
29707b206c security: replace strict_strto*() with kstrto*()
The usage of strict_strto*() is not preferred, because
strict_strto*() is obsolete. Thus, kstrto*() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-02-06 19:11:04 +11:00
James Morris
38fd2c202a Merge to v3.13-rc7 for prerequisite changes in the Xen code for TPM 2014-01-06 22:23:01 +11:00
Roberto Sassu
dcf4e39286 ima: remove unneeded size_limit argument from ima_eventdigest_init_common()
This patch removes the 'size_limit' argument from
ima_eventdigest_init_common(). Since the 'd' field will never include
the hash algorithm as prefix and the 'd-ng' will always have it, we can
use the hash algorithm to differentiate the two cases in the modified
function (it is equal to HASH_ALGO__LAST in the first case, the opposite
in the second).

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-01-03 07:43:00 -05:00