Commit Graph

212 Commits

Author SHA1 Message Date
Roberto Sassu
dbc335d2dc ima: make a copy of template_fmt in template_desc_init_fields()
This patch makes a copy of the 'template_fmt' function argument so that
the latter will not be modified by strsep(), which does the splitting by
replacing the given separator with '\0'.

 IMA: No TPM chip found, activating TPM-bypass!
 Unable to handle kernel pointer dereference at virtual kernel address 0000000000842000
 Oops: 0004 [#1] SMP
 Modules linked in:
 CPU: 3 PID: 1 Comm: swapper/0 Not tainted 3.12.0-rc2-00098-g3ce1217d6cd5 #17
 task: 000000003ffa0000 ti: 000000003ff84000 task.ti: 000000003ff84000
 Krnl PSW : 0704e00180000000 000000000044bf88 (strsep+0x7c/0xa0)
            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3
 Krnl GPRS: 000000000000007c 000000000000007c 000000003ff87d90 0000000000821fd8
            0000000000000000 000000000000007c 0000000000aa37e0 0000000000aa9008
            0000000000000051 0000000000a114d8 0000000100000002 0000000000842bde
            0000000000842bdf 00000000006f97f0 000000000040062c 000000003ff87cf0
 Krnl Code: 000000000044bf7c: a7f4000a           brc     15,44bf90
            000000000044bf80: b90200cc           ltgr    %r12,%r12
           #000000000044bf84: a7840006           brc     8,44bf90
           >000000000044bf88: 9200c000           mvi     0(%r12),0
            000000000044bf8c: 41c0c001           la      %r12,1(%r12)
            000000000044bf90: e3c020000024       stg     %r12,0(%r2)
            000000000044bf96: b904002b           lgr     %r2,%r11
            000000000044bf9a: ebbcf0700004       lmg     %r11,%r12,112(%r15)
 Call Trace:
 ([<00000000004005fe>] ima_init_template+0xa2/0x1bc)
  [<0000000000a7c896>] ima_init+0x7a/0xa8
  [<0000000000a7c938>] init_ima+0x24/0x40
  [<00000000001000e8>] do_one_initcall+0x68/0x128
  [<0000000000a4eb56>] kernel_init_freeable+0x20a/0x2b4
  [<00000000006a1ff4>] kernel_init+0x30/0x178
  [<00000000006b69fe>] kernel_thread_starter+0x6/0xc
  [<00000000006b69f8>] kernel_thread_starter+0x0/0xc
 Last Breaking-Event-Address:
  [<000000000044bf42>] strsep+0x36/0xa0

Fixes commit: adf53a7 ima: new templates management mechanism

Changelog v1:
- make template_fmt 'const char *' (reported-by James Morris)
- fix kstrdup memory leak (reported-by James Morris)

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2013-11-25 15:05:33 -05:00
Roberto Sassu
3e8e5503a3 ima: do not send field length to userspace for digest of ima template
This patch defines a new value for the 'ima_show_type' enumerator
(IMA_SHOW_BINARY_NO_FIELD_LEN) to prevent that the field length
is transmitted through the 'binary_runtime_measurements' interface
for the digest field of the 'ima' template.

Fixes commit: 3ce1217 ima: define template fields library and new helpers

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-11-25 07:31:14 -05:00
Roberto Sassu
b6f8f16f41 ima: do not include field length in template digest calc for ima template
To maintain compatibility with userspace tools, the field length must not
be included in the template digest calculation for the 'ima' template.

Fixes commit: a71dc65 ima: switch to new template management mechanism

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-11-25 07:26:28 -05:00
Linus Torvalds
34ef7bd382 Revert "ima: define '_ima' as a builtin 'trusted' keyring"
This reverts commit 217091dd7a, which
caused the following build error:

  security/integrity/digsig.c:70:5: error: redefinition of ‘integrity_init_keyring’
  security/integrity/integrity.h:149:12: note: previous definition of ‘integrity_init_keyring’ w
  security/integrity/integrity.h:149:12: warning: ‘integrity_init_keyring’ defined but not used

reported by Krzysztof Kolasa. Mimi says:

 "I made the classic mistake of requesting this patch to be upstreamed
  at the last second, rather than waiting until the next open window.

  At this point, the best course would probably be to revert the two
  commits and fix them for the next open window"

Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-23 16:36:35 -08:00
Mimi Zohar
217091dd7a 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:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2013-10-31 20:20:48 -04:00
Mimi Zohar
bcbc9b0cf6 ima: extend the measurement list to include the file signature
This patch defines a new template called 'ima-sig', which includes
the file signature in the template data, in addition to the file's
digest and pathname.

A template is composed of a set of fields.  Associated with each
field is an initialization and display function.  This patch defines
a new template field called 'sig', the initialization function
ima_eventsig_init(), and the display function ima_show_template_sig().

This patch modifies the .field_init() function definition to include
the 'security.ima' extended attribute and length.

Changelog:
- remove unused code (Dmitry Kasatkin)
- avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu)
- rename DATA_FMT_SIG to DATA_FMT_HEX
- cleanup ima_eventsig_init() based on Roberto's comments

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
2013-10-31 20:19:35 -04:00
Dmitry Kasatkin
3ea7a56067 ima: provide hash algo info in the xattr
All files labeled with 'security.ima' hashes, are hashed using the
same hash algorithm.  Changing from one hash algorithm to another,
requires relabeling the filesystem.  This patch defines a new xattr
type, which includes the hash algorithm, permitting different files
to be hashed with different algorithms.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-26 21:32:55 -04:00
Mimi Zohar
e7a2ad7eb6 ima: enable support for larger default filedata hash algorithms
The IMA measurement list contains two hashes - a template data hash
and a filedata hash.  The template data hash is committed to the TPM,
which is limited, by the TPM v1.2 specification, to 20 bytes.  The
filedata hash is defined as 20 bytes as well.

Now that support for variable length measurement list templates was
added, the filedata hash is not limited to 20 bytes.  This patch adds
Kconfig support for defining larger default filedata hash algorithms
and replacing the builtin default with one specified on the kernel
command line.

<uapi/linux/hash_info.h> contains a list of hash algorithms.  The
Kconfig default hash algorithm is a subset of this list, but any hash
algorithm included in the list can be specified at boot, using the
'ima_hash=' kernel command line option.

Changelog v2:
- update Kconfig

Changelog:
- support hashes that are configured
- use generic HASH_ALGO_ definitions
- add Kconfig support
- hash_setup must be called only once (Dmitry)
- removed trailing whitespaces (Roberto Sassu)

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
2013-10-26 21:32:55 -04:00
Roberto Sassu
9b9d4ce592 ima: define kernel parameter 'ima_template=' to change configured default
This patch allows users to specify from the kernel command line the
template descriptor, among those defined, that will be used to generate
and display measurement entries. If an user specifies a wrong template,
IMA reverts to the template descriptor set in the kernel configuration.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-26 21:32:54 -04:00
Mimi Zohar
4286587dcc ima: add Kconfig default measurement list template
This patch adds a Kconfig option to select the default IMA
measurement list template.  The 'ima' template limited the
filedata hash to 20 bytes and the pathname to 255 charaters.
The 'ima-ng' measurement list template permits larger hash
digests and longer pathnames.

Changelog:
- keep 'select CRYPTO_HASH_INFO' in 'config IMA' section (Kconfig)
  (Roberto Sassu);
- removed trailing whitespaces (Roberto Sassu).
- Lindent fixes

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
2013-10-26 21:32:54 -04:00
Roberto Sassu
add1c05dce ima: defer determining the appraisal hash algorithm for 'ima' template
The same hash algorithm should be used for calculating the file
data hash for the IMA measurement list, as for appraising the file
data integrity.  (The appraise hash algorithm is stored in the
'security.ima' extended attribute.)  The exception is when the
reference file data hash digest, stored in the extended attribute,
is larger than the one supported by the template.  In this case,
the file data hash needs to be calculated twice, once for the
measurement list and, again, for appraisal.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-26 21:32:53 -04:00
Mimi Zohar
5278aa52f3 ima: add audit log support for larger hashes
Different files might be signed based on different hash algorithms.
This patch prefixes the audit log measurement hash with the hash
algorithm.

Changelog:
- use generic HASH_ALGO defintions
- use ':' as delimiter between the hash algorithm and the digest
  (Roberto Sassu)
- always include the hash algorithm used when audit-logging a measurement

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Peter Moody <pmoody@google.com>
2013-10-26 21:32:46 -04:00
Roberto Sassu
a71dc65d30 ima: switch to new template management mechanism
This patch performs the switch to the new template mechanism by modifying
the functions ima_alloc_init_template(), ima_measurements_show() and
ima_ascii_measurements_show(). The old function ima_template_show() was
removed as it is no longer needed. Also, if the template descriptor used
to generate a measurement entry is not 'ima', the whole length of field
data stored for an entry is provided before the data itself through the
binary_runtime_measurement interface.

Changelog:
- unnecessary to use strncmp() (Mimi Zohar)
- create new variable 'field' in ima_alloc_init_template() (Roberto Sassu)
- use GFP_NOFS flag in ima_alloc_init_template() (Roberto Sassu)
- new variable 'num_fields' in ima_store_template() (Roberto Sassu,
  proposed by Mimi Zohar)
- rename ima_calc_buffer_hash/template_hash() to ima_calc_field_array_hash(),
  something more generic (Mimi, requested by Dmitry)
- sparse error fix - Fengguang Wu
- fix lindent warnings
- always include the field length in the template data length
- include the template field length variable size in the template data length
- include both the template field data and field length in the template digest
  calculation. Simplifies verifying the template digest. (Mimi)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:06 -04:00
Roberto Sassu
4d7aeee73f ima: define new template ima-ng and template fields d-ng and n-ng
This patch adds support for the new template 'ima-ng', whose format
is defined as 'd-ng|n-ng'.  These new field definitions remove the
size limitations of the original 'ima' template.  Further, the 'd-ng'
field prefixes the inode digest with the hash algorithim, when
displaying the new larger digest sizes.

Change log:
- scripts/Lindent fixes  - Mimi
- "always true comparison" - reported by Fengguang Wu, resolved Dmitry
- initialize hash_algo variable to HASH_ALGO__LAST
- always prefix digest with hash algorithm - Mimi

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:05 -04:00
Roberto Sassu
3ce1217d6c ima: define template fields library and new helpers
This patch defines a library containing two initial template fields,
inode digest (d) and file name (n), the 'ima' template descriptor,
whose format is 'd|n', and two helper functions,
ima_write_template_field_data() and ima_show_template_field_data().

Changelog:
- replace ima_eventname_init() parameter NULL checking with BUG_ON.
  (suggested by Mimi)
- include "new template fields for inode digest (d) and file name (n)"
  definitions to fix a compiler warning.  - Mimi
- unnecessary to prefix static function names with 'ima_'. remove
  prefix to resolve Lindent formatting changes. - Mimi
- abbreviated/removed inline comments - Mimi
- always send the template field length - Mimi

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:05 -04:00
Roberto Sassu
adf53a778a ima: new templates management mechanism
The original 'ima' template is fixed length, containing the filedata hash
and pathname.  The filedata hash is limited to 20 bytes (md5/sha1).  The
pathname is a null terminated string, limited to 255 characters.  To
overcome these limitations and to add additional file metadata, it is
necessary to extend the current version of IMA by defining additional
templates.

The main reason to introduce this feature is that, each time a new
template is defined, the functions that generate and display the
measurement list would include the code for handling a new format and,
thus, would significantly grow over time.

This patch set solves this problem by separating the template management
from the remaining IMA code. The core of this solution is the definition
of two new data structures: a template descriptor, to determine which
information should be included in the measurement list, and a template
field, to generate and display data of a given type.

To define a new template field, developers define the field identifier
and implement two functions, init() and show(), respectively to generate
and display measurement entries.  Initially, this patch set defines the
following template fields (support for additional data types will be
added later):
 - 'd': the digest of the event (i.e. the digest of a measured file),
        calculated with the SHA1 or MD5 hash algorithm;
 - 'n': the name of the event (i.e. the file name), with size up to
        255 bytes;
 - 'd-ng': the digest of the event, calculated with an arbitrary hash
           algorithm (field format: [<hash algo>:]digest, where the digest
           prefix is shown only if the hash algorithm is not SHA1 or MD5);
 - 'n-ng': the name of the event, without size limitations.

Defining a new template descriptor requires specifying the template format,
a string of field identifiers separated by the '|' character.  This patch
set defines the following template descriptors:
 - "ima": its format is 'd|n';
 - "ima-ng" (default): its format is 'd-ng|n-ng'

Further details about the new template architecture can be found in
Documentation/security/IMA-templates.txt.

Changelog:
- don't defer calling ima_init_template() - Mimi
- don't define ima_lookup_template_desc() until used - Mimi
- squashed with documentation patch - Mimi

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:04 -04:00
Roberto Sassu
7bc5f447ce ima: define new function ima_alloc_init_template() to API
Instead of allocating and initializing the template entry from multiple
places (eg. boot aggregate, violation, and regular measurements), this
patch defines a new function called ima_alloc_init_template().  The new
function allocates and initializes the measurement entry with the inode
digest and the filename.

In respect to the current behavior, it truncates the file name passed
in the 'filename' argument if the latter's size is greater than 255 bytes
and the passed file descriptor is NULL.

Changelog:
- initialize 'hash' variable for non TPM case - Mimi
- conform to expectation for 'iint' to be defined as a pointer. - Mimi
- add missing 'file' dependency for recalculating file hash. - Mimi

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:04 -04:00
Roberto Sassu
9803d413f4 ima: pass the filename argument up to ima_add_template_entry()
Pass the filename argument to ima_add_template_entry() in order to
eliminate a dependency on template specific data (third argument of
integrity_audit_msg).

This change is required because, with the new template management
mechanism, the generation of a new measurement entry will be performed
by new specific functions (introduced in next patches) and the current IMA
code will not be aware anymore of how data is stored in the entry payload.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:03 -04:00
Roberto Sassu
7d802a227b ima: pass the file descriptor to ima_add_violation()
Pass the file descriptor instead of the inode to ima_add_violation(),
to make the latter consistent with ima_store_measurement() in
preparation for the new template architecture.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:02 -04:00
Dmitry Kasatkin
09ef54359c ima: ima_calc_boot_agregate must use SHA1
With multiple hash algorithms, ima_hash_tfm is no longer guaranteed to be sha1.
Need to force to use sha1.

Changelog:
- pass ima_digest_data to ima_calc_boot_aggregate() instead of char *
  (Roberto Sassu);
- create an ima_digest_data structure in ima_add_boot_aggregate()
  (Roberto Sassu);
- pass hash->algo to ima_alloc_tfm() (Roberto Sassu, reported by Dmitry).
- "move hash definition in ima_add_boot_aggregate()" commit hunk to here.
- sparse warning fix - Fengguang Wu

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:02 -04:00
Dmitry Kasatkin
ea593993d3 ima: support arbitrary hash algorithms in ima_calc_buffer_hash
ima_calc_buffer_hash will be used with different hash algorithms.
This patch provides support for arbitrary hash algorithms in
ima_calc_buffer_hash.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:01 -04:00
Dmitry Kasatkin
723326b927 ima: provide dedicated hash algo allocation function
This patch provides dedicated hash algo allocation and
deallocation function which can be used by different clients.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:01 -04:00
Mimi Zohar
140d802240 ima: differentiate between template hash and file data hash sizes
The TPM v1.2 limits the template hash size to 20 bytes.  This
patch differentiates between the template hash size, as defined
in the ima_template_entry, and the file data hash size, as
defined in the ima_template_data.  Subsequent patches add support
for different file data hash algorithms.

Change log:
- hash digest definition in ima_store_template() should be TPM_DIGEST_SIZE

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2013-10-25 17:17:00 -04:00
Dmitry Kasatkin
a35c3fb649 ima: use dynamically allocated hash storage
For each inode in the IMA policy, an iint is allocated.  To support
larger hash digests, the iint digest size changed from 20 bytes to
the maximum supported hash digest size.  Instead of allocating the
maximum size, which most likely is not needed, this patch dynamically
allocates the needed hash storage.

Changelog:
- fix krealloc bug

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:17:00 -04:00
Dmitry Kasatkin
b1aaab22e2 ima: pass full xattr with the signature
For possibility to use xattr type for new signature formats,
pass full xattr to the signature verification function.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:16:59 -04:00