Right now security_get_user_sids() will pass in a NULL avd pointer to
avc_has_perm_noaudit(), which then forces that function to have a dummy
entry for that case and just generally test it.
Don't do it. The normal callers all pass a real avd pointer, and this
helper function is incredibly hot. So don't make avc_has_perm_noaudit()
do conditional stuff that isn't needed for the common case.
This also avoids some duplicated stack space.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To shorten the list we need to run if filename trans rules exist for the type
of the given parent directory I put them in a hashtable. Given the policy we
are expecting to use in Fedora this takes the worst case list run from about
5,000 entries to 17.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Right now we walk to filename trans rule list for every inode that is
created. First passes at policy using this facility creates around 5000
filename trans rules. Running a list of 5000 entries every time is a bad
idea. This patch adds a new ebitmap to policy which has a bit set for each
ttype that has at least 1 filename trans rule. Thus when an inode is
created we can quickly determine if any rules exist for this parent
directory type and can skip the list if we know there is definitely no
relevant entry.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
filename_compute_type() takes as arguments the numeric value of the type of
the subject and target. It does not take a context. Thus the names are
misleading. Fix the argument names.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
filename_compute_type used to take a qstr, but it now takes just a name.
Fix the comments to indicate it is an objname, not a qstr.
Signed-off-by: Eric Paris <eparis@redhat.com>
The len should be an size_t but is a ssize_t. Easy enough fix to silence
build warnings. We have no need for signed-ness.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Commit 6f5317e730 introduced a bug in the
handling of userspace object classes that is causing breakage for Xorg
when XSELinux is enabled. Fix the bug by changing map_class() to return
SECCLASS_NULL when the class cannot be mapped to a kernel object class.
Reported-by: "Justin P. Mattock" <justinmattock@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
The attached patch allows /selinux/create takes optional 4th argument
to support TYPE_TRANSITION with name extension for userspace object
managers.
If 4th argument is not supplied, it shall perform as existing kernel.
In fact, the regression test of SE-PostgreSQL works well on the patched
kernel.
Thanks,
Signed-off-by: KaiGai Kohei <kohei.kaigai@eu.nec.com>
[manually verify fuzz was not an issue, and it wasn't: eparis]
Signed-off-by: Eric Paris <eparis@redhat.com>
Commit 6f5317e730 introduced a bug in the
handling of userspace object classes that is causing breakage for Xorg
when XSELinux is enabled. Fix the bug by changing map_class() to return
SECCLASS_NULL when the class cannot be mapped to a kernel object class.
Reported-by: "Justin P. Mattock" <justinmattock@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Apply role_transition rules for all kinds of classes.
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>
The socket SID would be computed on creation and no longer inherit
its creator's SID by default. Socket may have a different type but
needs to retain the creator's role and MLS attribute in order not
to break labeled networking and network access control.
The kernel value for a class would be used to determine if the class
if one of socket classes. If security_compute_sid is called from
userspace the policy value for a class would be mapped to the relevant
kernel value first.
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Currently SELinux has rules which label new objects according to 3 criteria.
The label of the process creating the object, the label of the parent
directory, and the type of object (reg, dir, char, block, etc.) This patch
adds a 4th criteria, the dentry name, thus we can distinguish between
creating a file in an etc_t directory called shadow and one called motd.
There is no file globbing, regex parsing, or anything mystical. Either the
policy exactly (strcmp) matches the dentry name of the object or it doesn't.
This patch has no changes from today if policy does not implement the new
rules.
Signed-off-by: Eric Paris <eparis@redhat.com>
The sym_val_to_name type array can be quite large as it grows linearly with
the number of types. With known policies having over 5k types these
allocations are growing large enough that they are likely to fail. Convert
those to flex_array so no allocation is larger than PAGE_SIZE
Signed-off-by: Eric Paris <eparis@redhat.com>
In rawhide type_val_to_struct will allocate 26848 bytes, an order 3
allocations. While this hasn't been seen to fail it isn't outside the
realm of possibiliy on systems with severe memory fragmentation. Convert
to flex_array so no allocation will ever be bigger than PAGE_SIZE.
Signed-off-by: Eric Paris <eparis@redhat.com>
security_netlbl_secattr_to_sid is difficult to follow, especially the
return codes. Try to make the function obvious.
Signed-off-by: Eric Paris <eparis@redhat.com>
selinuxfs.c has lots of different standards on how to handle return paths on
error. For the most part transition to
rc=errno
if (failure)
goto out;
[...]
out:
cleanup()
return rc;
Instead of doing cleanup mid function, or having multiple returns or other
options. This doesn't do that for every function, but most of the complex
functions which have cleanup routines on error.
Signed-off-by: Eric Paris <eparis@redhat.com>
/selinux/policy allows a user to copy the policy back out of the kernel.
This patch allows userspace to actually mmap that file and use it directly.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
There is interest in being able to see what the actual policy is that was
loaded into the kernel. The patch creates a new selinuxfs file
/selinux/policy which can be read by userspace. The actual policy that is
loaded into the kernel will be written back out to userspace.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
With the (long ago) interface change to have the secid_to_secctx functions
do the string allocation instead of having the caller do the allocation we
lost the ability to query the security server for the length of the
upcoming string. The SECMARK code would like to allocate a netlink skb
with enough length to hold the string but it is just too unclean to do the
string allocation twice or to do the allocation the first time and hold
onto the string and slen. This patch adds the ability to call
security_secid_to_secctx() with a NULL data pointer and it will just set
the slen pointer.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
This patch provides a new /selinux/status entry which allows applications
read-only mmap(2).
This region reflects selinux_kernel_status structure in kernel space.
struct selinux_kernel_status
{
u32 length; /* length of this structure */
u32 sequence; /* sequence number of seqlock logic */
u32 enforcing; /* current setting of enforcing mode */
u32 policyload; /* times of policy reloaded */
u32 deny_unknown; /* current setting of deny_unknown */
};
When userspace object manager caches access control decisions provided
by SELinux, it needs to invalidate the cache on policy reload and setenforce
to keep consistency.
However, the applications need to check the kernel state for each accesses
on userspace avc, or launch a background worker process.
In heuristic, frequency of invalidation is much less than frequency of
making access control decision, so it is annoying to invoke a system call
to check we don't need to invalidate the userspace cache.
If we can use a background worker thread, it allows to receive invalidation
messages from the kernel. But it requires us an invasive coding toward the
base application in some cases; E.g, when we provide a feature performing
with SELinux as a plugin module, it is unwelcome manner to launch its own
worker thread from the module.
If we could map /selinux/status to process memory space, application can
know updates of selinux status; policy reload or setenforce.
A typical application checks selinux_kernel_status::sequence when it tries
to reference userspace avc. If it was changed from the last time when it
checked userspace avc, it means something was updated in the kernel space.
Then, the application can reset userspace avc or update current enforcing
mode, without any system call invocations.
This sequence number is updated according to the seqlock logic, so we need
to wait for a while if it is odd number.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Eric Paris <eparis@redhat.com>
--
security/selinux/include/security.h | 21 ++++++
security/selinux/selinuxfs.c | 56 +++++++++++++++
security/selinux/ss/Makefile | 2 +-
security/selinux/ss/services.c | 3 +
security/selinux/ss/status.c | 129 +++++++++++++++++++++++++++++++++++
5 files changed, 210 insertions(+), 1 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>
Current selinux policy can have over 3000 types. The type_attr_map in
policy is an array sized by the number of types times sizeof(struct ebitmap)
(12 on x86_64). Basic math tells us the array is going to be of length
3000 x 12 = 36,000 bytes. The largest 'safe' allocation on a long running
system is 16k. Most of the time a 32k allocation will work. But on long
running systems a 64k allocation (what we need) can fail quite regularly.
In order to deal with this I am converting the type_attr_map to use
flex_arrays. Let the library code deal with breaking this into PAGE_SIZE
pieces.
-v2
rework some of the if(!obj) BUG() to be BUG_ON(!obj)
drop flex_array_put() calls and just use a _get() object directly
-v3
make apply to James' tree (drop the policydb_write changes)
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
policy load failure always return EINVAL even if the failure was for some
other reason (usually ENOMEM). This patch passes error codes back up the
stack where they will make their way to userspace. This might help in
debugging future problems with policy load.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
This patch revert the commit of 7d52a155e3
which removed a part of type_attribute_bounds_av as a dead code.
However, at that time, we didn't find out the target side boundary allows
to handle some of pseudo /proc/<pid>/* entries with its process's security
context well.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
--
security/selinux/ss/services.c | 43 ++++++++++++++++++++++++++++++++++++---
1 files changed, 39 insertions(+), 4 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>
Fix a couple of sparse warnings for callers of
context_struct_to_string, which takes a *u32, not an *int.
These cases are harmless as the values are not used.
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Allow runtime switching between different policy types (e.g. from a MLS/MCS
policy to a non-MLS/non-MCS policy or viceversa).
Signed-off-by: Guido Trentalancia <guido@trentalancia.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Always load the initial SIDs, even in the case of a policy
reload and not just at the initial policy load. This comes
particularly handy after the introduction of a recent
patch for enabling runtime switching between different
policy types, although this patch is in theory independent
from that feature.
Signed-off-by: Guido Trentalancia <guido@trentalancia.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
This patch removes dead code in type_attribute_bounds_av().
Due to the historical reason, the type boundary feature is delivered
from hierarchical types in libsepol, it has supported boundary features
both of subject type (domain; in most cases) and target type.
However, we don't have any actual use cases in bounded target types,
and it tended to make conceptual confusion.
So, this patch removes the dead code to apply boundary checks on the
target types. I makes clear the TYPEBOUNDS restricts privileges of
a certain domain bounded to any other domain.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
--
security/selinux/ss/services.c | 43 +++------------------------------------
1 files changed, 4 insertions(+), 39 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>
If allow_unknown==deny, SELinux treats an undefined kernel security
class as an error condition rather than as a typical permission denial
and thus does not allow permissions on undefined classes even when in
permissive mode. Change the SELinux logic so that this case is handled
as a typical permission denial, subject to the usual permissive mode and
permissive domain handling.
Also drop the 'requested' argument from security_compute_av() and
helpers as it is a legacy of the original security server interface and
is unused.
Changes:
- Handle permissive domains consistently by moving up the test for a
permissive domain.
- Make security_compute_av_user() consistent with security_compute_av();
the only difference now is that security_compute_av() performs mapping
between the kernel-private class and permission indices and the policy
values. In the userspace case, this mapping is handled by libselinux.
- Moved avd_init inside the policy lock.
Based in part on a patch by Paul Moore <paul.moore@hp.com>.
Reported-by: Andrew Worsley <amworsley@gmail.com>
Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The size argument to kcalloc should be the size of desired structure,
not the pointer to it.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@expression@
expression *x;
@@
x =
<+...
-sizeof(x)
+sizeof(*x)
...+>// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Historically we've seen cases where permissions are requested for classes
where they do not exist. In particular we have seen CIFS forget to set
i_mode to indicate it is a directory so when we later check something like
remove_name we have problems since it wasn't defined in tclass file. This
used to result in a avc which included the permission 0x2000 or something.
Currently the kernel will deny the operations (good thing) but will not
print ANY information (bad thing). First the auditdeny field is no
extended to include unknown permissions. After that is fixed the logic in
avc_dump_query to output this information isn't right since it will remove
the permission from the av and print the phrase "<NULL>". This takes us
back to the behavior before the classmap rewrite.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Ensure that we release the policy read lock on all exit paths from
security_compute_av.
Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Drop remapping of netlink classes and bypass of permission checking
based on netlink message type for policy version < 18. This removes
compatibility code introduced when the original single netlink
security class used for all netlink sockets was split into
finer-grained netlink classes based on netlink protocol and when
permission checking was added based on netlink message type in Linux
2.6.8. The only known distribution that shipped with SELinux and
policy < 18 was Fedora Core 2, which was EOL'd on 2005-04-11.
Given that the remapping code was never updated to address the
addition of newer netlink classes, that the corresponding userland
support was dropped in 2005, and that the assumptions made by the
remapping code about the fixed ordering among netlink classes in the
policy may be violated in the future due to the dynamic class/perm
discovery support, we should drop this compatibility code now.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Modify SELinux to dynamically discover class and permission values
upon policy load, based on the dynamic object class/perm discovery
logic from libselinux. A mapping is created between kernel-private
class and permission indices used outside the security server and the
policy values used within the security server.
The mappings are only applied upon kernel-internal computations;
similar mappings for the private indices of userspace object managers
is handled on a per-object manager basis by the userspace AVC. The
interfaces for compute_av and transition_sid are split for kernel
vs. userspace; the userspace functions are distinguished by a _user
suffix.
The kernel-private class indices are no longer tied to the policy
values and thus do not need to skip indices for userspace classes;
thus the kernel class index values are compressed. The flask.h
definitions were regenerated by deleting the userspace classes from
refpolicy's definitions and then regenerating the headers. Going
forward, we can just maintain the flask.h, av_permissions.h, and
classmap.h definitions separately from policy as they are no longer
tied to the policy values. The next patch introduces a utility to
automate generation of flask.h and av_permissions.h from the
classmap.h definitions.
The older kernel class and permission string tables are removed and
replaced by a single security class mapping table that is walked at
policy load to generate the mapping. The old kernel class validation
logic is completely replaced by the mapping logic.
The handle unknown logic is reworked. reject_unknown=1 is handled
when the mappings are computed at policy load time, similar to the old
handling by the class validation logic. allow_unknown=1 is handled
when computing and mapping decisions - if the permission was not able
to be mapped (i.e. undefined, mapped to zero), then it is
automatically added to the allowed vector. If the class was not able
to be mapped (i.e. undefined, mapped to zero), then all permissions
are allowed for it if allow_unknown=1.
avc_audit leverages the new security class mapping table to lookup the
class and permission names from the kernel-private indices.
The mdp program is updated to use the new table when generating the
class definitions and allow rules for a minimal boot policy for the
kernel. It should be noted that this policy will not include any
userspace classes, nor will its policy index values for the kernel
classes correspond with the ones in refpolicy (they will instead match
the kernel-private indices).
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
The attached patch adds support to generate audit messages on two cases.
The first one is a case when a multi-thread process tries to switch its
performing security context using setcon(3), but new security context is
not bounded by the old one.
type=SELINUX_ERR msg=audit(1245311998.599:17): \
op=security_bounded_transition result=denied \
oldcontext=system_u:system_r:httpd_t:s0 \
newcontext=system_u:system_r:guest_webapp_t:s0
The other one is a case when security_compute_av() masked any permissions
due to the type boundary violation.
type=SELINUX_ERR msg=audit(1245312836.035:32): \
op=security_compute_av reason=bounds \
scontext=system_u:object_r:user_webapp_t:s0 \
tcontext=system_u:object_r:shadow_t:s0:c0 \
tclass=file perms=getattr,open
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
It is a cleanup patch to cut down a line within 80 columns.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
--
security/selinux/ss/services.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>
This patch enables applications to handle permissive domain correctly.
Since the v2.6.26 kernel, SELinux has supported an idea of permissive
domain which allows certain processes to work as if permissive mode,
even if the global setting is enforcing mode.
However, we don't have an application program interface to inform
what domains are permissive one, and what domains are not.
It means applications focuses on SELinux (XACE/SELinux, SE-PostgreSQL
and so on) cannot handle permissive domain correctly.
This patch add the sixth field (flags) on the reply of the /selinux/access
interface which is used to make an access control decision from userspace.
If the first bit of the flags field is positive, it means the required
access control decision is on permissive domain, so application should
allow any required actions, as the kernel doing.
This patch also has a side benefit. The av_decision.flags is set at
context_struct_compute_av(). It enables to check required permissions
without read_lock(&policy_rwlock).
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
--
security/selinux/avc.c | 2 +-
security/selinux/include/security.h | 4 +++-
security/selinux/selinuxfs.c | 4 ++--
security/selinux/ss/services.c | 30 +++++-------------------------
4 files changed, 11 insertions(+), 29 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>
It appears there was an intention to have the security server only decide
certain permissions and leave other for later as some sort of a portential
performance win. We are currently always deciding all 32 bits of
permissions and this is a useless couple of branches and wasted space.
This patch completely drops the av.decided concept.
This in a 17% reduction in the time spent in avc_has_perm_noaudit
based on oprofile sampling of a tbench benchmark.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Don't store the field->op in the messy (and very inconvenient for e.g.
audit_comparator()) form; translate to dense set of values and do full
validation of userland-submitted value while we are at it.
->audit_init_rule() and ->audit_match_rule() get new values now; in-tree
instances updated.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch provides support for including the LSM's secid in addition to
the LSM's MLS information in the NetLabel security attributes structure.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Currently when SELinux fails to allocate memory in
security_netlbl_sid_to_secattr() the NetLabel LSM domain field is set to
NULL which triggers the default NetLabel LSM domain mapping which may not
always be the desired mapping. This patch fixes this by returning an error
when the kernel is unable to allocate memory. This could result in more
failures on a system with heavy memory pressure but it is the "correct"
thing to do.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
At some point during the 2.6.27 development cycle two new fields were added
to the SELinux context structure, a string pointer and a length field. The
code in selinux_secattr_to_sid() was not modified and as a result these two
fields were left uninitialized which could result in erratic behavior,
including kernel panics, when NetLabel is used. This patch fixes the
problem by fully initializing the context in selinux_secattr_to_sid() before
use and reducing the level of direct context manipulation done to help
prevent future problems.
Please apply this to the 2.6.27-rcX release stream.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Linus Torvalds