The new templates management mechanism records information associated
to an event into an array of 'ima_field_data' structures and makes it
available through the 'template_data' field of the 'ima_template_entry'
structure (the element of the measurements list created by IMA).
Since 'ima_field_data' contains dynamically allocated data (which length
varies depending on the data associated to a selected template field),
it is not enough to just free the memory reserved for a
'ima_template_entry' structure if something goes wrong.
This patch creates the new function ima_free_template_entry() which
walks the array of 'ima_field_data' structures, frees the memory
referenced by the 'data' pointer and finally the space reserved for
the 'ima_template_entry' structure. Further, it replaces existing kfree()
that have a pointer to an 'ima_template_entry' structure as argument
with calls to the new function.
Fixes: a71dc65: ima: switch to new template management mechanism
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
7bc5f447ce (ima: define new function ima_alloc_init_template() to
API) moved the initialization of 'entry' in ima_add_boot_aggregate() a
bit more below, after the if (ima_used_chip).
So, 'entry' is not initialized while being inside this if-block. So, we
should not attempt to free it.
Found by Coverity (CID: 1131971)
Fixes: 7bc5f447ce (ima: define new function ima_alloc_init_template() to API)
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
This patch stores the address of the 'template_fmt_copy' variable in a new
variable, called 'template_fmt_ptr', so that the latter is passed as an
argument of strsep() instead of the former. This modification is needed
in order to correctly free the memory area referenced by
'template_fmt_copy' (strsep() modifies the pointer of the passed string).
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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>
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>
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>
Key pointers stored in the keyring are marked in bit 1 to indicate if they
point to a keyring. We need to strip off this bit before using the pointer
when iterating over the keyring for the purpose of looking for links to garbage
collect.
This means that expirable keyrings aren't correctly expiring because the
checker is seeing their key pointer with 2 added to it.
Since the fix for this involves knowing about the internals of the keyring,
key_gc_keyring() is moved to keyring.c and merged into keyring_gc().
This can be tested by:
echo 2 >/proc/sys/kernel/keys/gc_delay
keyctl timeout `keyctl add keyring qwerty "" @s` 2
cat /proc/keys
sleep 5; cat /proc/keys
which should see a keyring called "qwerty" appear in the session keyring and
then disappear after it expires, and:
echo 2 >/proc/sys/kernel/keys/gc_delay
a=`keyctl get_persistent @s`
b=`keyctl add keyring 0 "" $a`
keyctl add user a a $b
keyctl timeout $b 2
cat /proc/keys
sleep 5; cat /proc/keys
which should see a keyring called "0" with a key called "a" in it appear in the
user's persistent keyring (which will be attached to the session keyring) and
then both the "0" keyring and the "a" key should disappear when the "0" keyring
expires.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Simo Sorce <simo@redhat.com>
In the big_key_instantiate() function we return 0 if kernel_write() returns us
an error rather than returning an error. This can potentially lead to
dentry_open() giving a BUG when called from big_key_read() with an unset
tmpfile path.
------------[ cut here ]------------
kernel BUG at fs/open.c:798!
...
RIP: 0010:[<ffffffff8119bbd1>] dentry_open+0xd1/0xe0
...
Call Trace:
[<ffffffff812350c5>] big_key_read+0x55/0x100
[<ffffffff81231084>] keyctl_read_key+0xb4/0xe0
[<ffffffff81231e58>] SyS_keyctl+0xf8/0x1d0
[<ffffffff815bb799>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Stephen Gallagher <sgallagh@redhat.com>
If the UID is specified by userspace when calling the KEYCTL_GET_PERSISTENT
function and the process does not have the CAP_SETUID capability, then the
function will return -EPERM if the current process's uid, suid, euid and fsuid
all match the requested UID. This is incorrect.
Fix it such that when a non-privileged caller requests a persistent keyring by
a specific UID they can only request their own (ie. the specified UID matches
either then process's UID or the process's EUID).
This can be tested by logging in as the user and doing:
keyctl get_persistent @p
keyctl get_persistent @p `id -u`
keyctl get_persistent @p 0
The first two should successfully print the same key ID. The third should do
the same if called by UID 0 or indicate Operation Not Permitted otherwise.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephen Gallagher <sgallagh@redhat.com>
Supress the stock memory allocation failure warnings for audit buffers
since audit alreay takes care of memory allocation failure warnings, including
rate-limiting, in audit_log_start().
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
We use the read check to get the feature set (like AUDIT_GET) and the
write check to set the features (like AUDIT_SET).
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
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>
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>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David Howells <dhowells@redhat.com>
If a key is displaced from a keyring by a matching one, then four more bytes
of quota are allocated to the keyring - despite the fact that the keyring does
not change in size.
Further, when a key is unlinked from a keyring, the four bytes of quota
allocated the link isn't recovered and returned to the user's pool.
The first can be tested by repeating:
keyctl add big_key a fred @s
cat /proc/key-users
(Don't put it in a shell loop otherwise the garbage collector won't have time
to clear the displaced keys, thus affecting the result).
This was causing the kerberos keyring to run out of room fairly quickly.
The second can be tested by:
cat /proc/key-users
a=`keyctl add user a a @s`
cat /proc/key-users
keyctl unlink $a
sleep 1 # Give RCU a chance to delete the key
cat /proc/key-users
assuming no system activity that otherwise adds/removes keys, the amount of
key data allocated should go up (say 40/20000 -> 47/20000) and then return to
the original value at the end.
Reported-by: Stephen Gallagher <sgallagh@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Having the big_keys functionality as a module is very marginally useful.
The userspace code that would use this functionality will get odd error
messages from the keys layer if the module isn't loaded. The code itself
is fairly small, so just have this as a boolean option and not a tristate.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Unless task == current ptrace_parent(task) is not safe even under
rcu_read_lock() and most of the current users are not right.
So may_change_ptraced_domain(task) looks wrong as well. However it
is always called with task == current so the code is actually fine.
Remove this argument to make this fact clear.
Note: perhaps we should simply kill ptrace_parent(), it buys almost
nothing. And it is obviously racy, perhaps this should be fixed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
The reporting of the parent task info is a vestage from old versions of
apparmor. The need for this information was removed by unique null-
profiles before apparmor was upstreamed so remove this info from logging.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Now that aa_capabile no longer sets the task field it can be removed
and the lsm_audit version of the field can be used.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Mediation is based off of the cred but auditing includes the current
task which may not be related to the actual request.
Signed-off-by: John Johansen <john.johansen@canonical.com>
When the ptrace security hooks were split the addition of
a mode parameter was not taken advantage of in the Smack
ptrace access check. This changes the access check from
always looking for read and write access to using the
passed mode. This will make use of /proc much happier.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
All files on the filesystem, currently, are hashed using the same hash
algorithm. In preparation for files from different packages being
signed using different hash algorithms, this patch adds support for
reading the signature hash algorithm from the 'security.ima' extended
attribute and calculates the appropriate file data hash based on it.
Changelog:
- fix scripts Lindent and checkpatch msgs - Mimi
- fix md5 support for older version, which occupied 20 bytes in the
xattr, not the expected 16 bytes. Fix the comparison to compare
only the first 16 bytes.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
In preparation of supporting more hash algorithms with larger hash sizes
needed for signature verification, this patch replaces the 20 byte sized
digest, with a more flexible structure. The new structure includes the
hash algorithm, digest size, and digest.
Changelog:
- recalculate filedata hash for the measurement list, if the signature
hash digest size is greater than 20 bytes.
- use generic HASH_ALGO_
- make ima_calc_file_hash static
- scripts lindent and checkpatch fixes
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This reverts commit 4c2c392763.
Everything in the initramfs should be measured and appraised,
but until the initramfs has extended attribute support, at
least measured.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Cc: Stable Kernel <stable@kernel.org>
It is really only wanting to duplicate a check which is already done by the
cgroup subsystem.
With this patch, user jdoe still cannot move pid 1 into a devices cgroup
he owns, but now he can move his own other tasks into devices cgroups.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Aristeu Rozanski <aris@redhat.com>
Linux file locking does not follow the same rules
as other mechanisms. Even though it is a write operation
a process can set a read lock on files which it has open
only for read access. Two programs with read access to
a file can use read locks to communicate.
This is not acceptable in a Mandatory Access Control
environment. Smack treats setting a read lock as the
write operation that it is. Unfortunately, many programs
assume that setting a read lock is a read operation.
These programs are unhappy in the Smack environment.
This patch introduces a new access mode (lock) to address
this problem. A process with lock access to a file can
set a read lock. A process with write access to a file can
set a read lock or a write lock. This prevents a situation
where processes are granted write access just so they can
set read locks.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
BugLink: http://bugs.launchpad.net/bugs/1235977
The profile introspection seq file has a locking bug when policy is viewed
from a virtual root (task in a policy namespace), introspection from the
real root is not affected.
The test for root
while (parent) {
is correct for the real root, but incorrect for tasks in a policy namespace.
This allows the task to walk backup the policy tree past its virtual root
causing it to be unlocked before the virtual root should be in the p_stop
fn.
This results in the following lockdep back trace:
[ 78.479744] [ BUG: bad unlock balance detected! ]
[ 78.479792] 3.11.0-11-generic #17 Not tainted
[ 78.479838] -------------------------------------
[ 78.479885] grep/2223 is trying to release lock (&ns->lock) at:
[ 78.479952] [<ffffffff817bf3be>] mutex_unlock+0xe/0x10
[ 78.480002] but there are no more locks to release!
[ 78.480037]
[ 78.480037] other info that might help us debug this:
[ 78.480037] 1 lock held by grep/2223:
[ 78.480037] #0: (&p->lock){+.+.+.}, at: [<ffffffff812111bd>] seq_read+0x3d/0x3d0
[ 78.480037]
[ 78.480037] stack backtrace:
[ 78.480037] CPU: 0 PID: 2223 Comm: grep Not tainted 3.11.0-11-generic #17
[ 78.480037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 78.480037] ffffffff817bf3be ffff880007763d60 ffffffff817b97ef ffff8800189d2190
[ 78.480037] ffff880007763d88 ffffffff810e1c6e ffff88001f044730 ffff8800189d2190
[ 78.480037] ffffffff817bf3be ffff880007763e00 ffffffff810e5bd6 0000000724fe56b7
[ 78.480037] Call Trace:
[ 78.480037] [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10
[ 78.480037] [<ffffffff817b97ef>] dump_stack+0x54/0x74
[ 78.480037] [<ffffffff810e1c6e>] print_unlock_imbalance_bug+0xee/0x100
[ 78.480037] [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10
[ 78.480037] [<ffffffff810e5bd6>] lock_release_non_nested+0x226/0x300
[ 78.480037] [<ffffffff817bf2fe>] ? __mutex_unlock_slowpath+0xce/0x180
[ 78.480037] [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10
[ 78.480037] [<ffffffff810e5d5c>] lock_release+0xac/0x310
[ 78.480037] [<ffffffff817bf2b3>] __mutex_unlock_slowpath+0x83/0x180
[ 78.480037] [<ffffffff817bf3be>] mutex_unlock+0xe/0x10
[ 78.480037] [<ffffffff81376c91>] p_stop+0x51/0x90
[ 78.480037] [<ffffffff81211408>] seq_read+0x288/0x3d0
[ 78.480037] [<ffffffff811e9d9e>] vfs_read+0x9e/0x170
[ 78.480037] [<ffffffff811ea8cc>] SyS_read+0x4c/0xa0
[ 78.480037] [<ffffffff817ccc9d>] system_call_fastpath+0x1a/0x1f
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Roberto Sassu