Don't flush inherited SIGKILL during execve() in SELinux's post cred commit
hook. This isn't really a security problem: if the SIGKILL came before the
credentials were changed, then we were right to receive it at the time, and
should honour it; if it came after the creds were changed, then we definitely
should honour it; and in any case, all that will happen is that the process
will be scrapped before it ever returns to userspace.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
We are still calling secondary_ops->sysctl even though the capabilities
module does not define a sysctl operation.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
the following patch moves checks for SMACK xattr validity
from smack_inode_post_setxattr (which cannot return an error to the user)
to smack_inode_setxattr (which can return an error).
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
the following patch, add logging of Smack security decisions.
This is of course very useful to understand what your current smack policy does.
As suggested by Casey, it also now forbids labels with ', " or \
It introduces a '/smack/logging' switch :
0: no logging
1: log denied (default)
2: log accepted
3: log denied&accepted
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
This patch creates auditing functions usable by LSM to audit security
events. It provides standard dumping of FS, NET, task etc ... events
(code borrowed from SELinux)
and provides 2 callbacks to define LSM specific auditing, which should be
flexible enough to convert SELinux too.
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
cked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
When request_key() is called, without there being any standard process
keyrings on which to fall back if a destination keyring is not specified, an
oops is liable to occur when construct_alloc_key() calls down_write() on
dest_keyring's semaphore.
Due to function inlining this may be seen as an oops in down_write() as called
from request_key_and_link().
This situation crops up during boot, where request_key() is called from within
the kernel (such as in CIFS mounts) where nobody is actually logged in, and so
PAM has not had a chance to create a session keyring and user keyrings to act
as the fallback.
To fix this, make construct_alloc_key() not attempt to cache a key if there is
no fallback key if no destination keyring is given specifically.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One-liner: capsh --print is broken without this patch.
In certain cases, cap_prctl returns error > 0 for success. However,
the 'no_change' label was always setting error to 0. As a result,
for example, 'prctl(CAP_BSET_READ, N)' would always return 0.
It should return 1 if a process has N in its bounding set (as
by default it does).
I'm keeping the no_change label even though it's now functionally
the same as 'error'.
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Since TOMOYO's policy management tools does not use the "undelete domain"
command, we decided to remove that command.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Since TOMOYO's policy management tools does not use the "undelete domain"
command, we decided to remove that command.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Export a number of functions for CacheFiles's use.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
Remove two unneeded exports and make two symbols static in fs/mpage.c
Cleanup after commit 585d3bc06f
Trim includes of fdtable.h
Don't crap into descriptor table in binfmt_som
Trim includes in binfmt_elf
Don't mess with descriptor table in load_elf_binary()
Get rid of indirect include of fs_struct.h
New helper - current_umask()
check_unsafe_exec() doesn't care about signal handlers sharing
New locking/refcounting for fs_struct
Take fs_struct handling to new file (fs/fs_struct.c)
Get rid of bumping fs_struct refcount in pivot_root(2)
Kill unsharing fs_struct in __set_personality()
There is nothing special that has to be protected by cgroup_lock,
so introduce devcgroup_mtuex for it's own use.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Distributions face a backward compatibility problem with starting to use
file capabilities. For instance, removing setuid root from ping and
doing setcap cap_net_raw=pe means that booting with an older kernel
or one compiled without file capabilities means ping won't work for
non-root users.
In order to replace the setuid root bit on a capability-unaware
program, one has to set the effective, or legacy, file capability,
which makes the capability effective immediately. This patch
uses the legacy bit as a queue to not automatically add full
privilege to a setuid-root program.
So, with this patch, an ordinary setuid-root program will run with
privilege. But if /bin/ping has both setuid-root and cap_net_raw in
fP and fE, then ping (when run by non-root user) will not run
with only cap_net_raw.
Changelog:
Apr 2 2009: Print a message once when such a binary is loaded,
as per James Morris' suggestion.
Apr 2 2009: Fix the condition to only catch uid!=0 && euid==0.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
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>
Don't pull it in sched.h; very few files actually need it and those
can include directly. sched.h itself only needs forward declaration
of struct fs_struct;
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch adds a new special option '-CIPSO' to the Smack subsystem. When used
in the netlabel list, it means "use CIPSO networking". A use case is when your
local network speaks CIPSO and you want also to connect to the unlabeled
Internet. This patch also add some documentation describing that. The patch
also corrects an oops when setting a '' SMACK64 xattr to a file.
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
This patch cleans up a lot of the Smack network access control code. The
largest changes are to fix the labeling of incoming TCP connections in a
manner similar to the recent SELinux changes which use the
security_inet_conn_request() hook to label the request_sock and let the label
move to the child socket via the normal network stack mechanisms. In addition
to the incoming TCP connection fixes this patch also removes the smk_labled
field from the socket_smack struct as the minor optimization advantage was
outweighed by the difficulty in maintaining it's proper state.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
The socket_post_accept() hook is not currently used by any in-tree modules
and its existence continues to cause problems by confusing people about
what can be safely accomplished using this hook. If a legitimate need for
this hook arises in the future it can always be reintroduced.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The SELinux "compat_net" is marked as deprecated, the time has come to
finally remove it from the kernel. Further code simplifications are
likely in the future, but this patch was intended to be a simple,
straight-up removal of the compat_net code.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The current NetLabel/SELinux behavior for incoming TCP connections works but
only through a series of happy coincidences that rely on the limited nature of
standard CIPSO (only able to convey MLS attributes) and the write equality
imposed by the SELinux MLS constraints. The problem is that network sockets
created as the result of an incoming TCP connection were not on-the-wire
labeled based on the security attributes of the parent socket but rather based
on the wire label of the remote peer. The issue had to do with how IP options
were managed as part of the network stack and where the LSM hooks were in
relation to the code which set the IP options on these newly created child
sockets. While NetLabel/SELinux did correctly set the socket's on-the-wire
label it was promptly cleared by the network stack and reset based on the IP
options of the remote peer.
This patch, in conjunction with a prior patch that adjusted the LSM hook
locations, works to set the correct on-the-wire label format for new incoming
connections through the security_inet_conn_request() hook. Besides the
correct behavior there are many advantages to this change, the most significant
is that all of the NetLabel socket labeling code in SELinux now lives in hooks
which can return error codes to the core stack which allows us to finally get
ride of the selinux_netlbl_inode_permission() logic which greatly simplfies
the NetLabel/SELinux glue code. In the process of developing this patch I
also ran into a small handful of AF_INET6 cleanliness issues that have been
fixed which should make the code safer and easier to extend in the future.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
the following patch (on top of 2.6.29) converts Smack lists to standard linux lists
Please review and consider for inclusion in 2.6.30-rc
regards,
Etienne
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Drop the printk message when an inode is found without an associated
dentry. This should only happen when userspace can't be accessing those
inodes and those labels will get set correctly on the next d_instantiate.
Thus there is no reason to send this message.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
New selinux permission to separate the ability to turn on tty auditing from
the ability to set audit rules.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
When I did open permissions I didn't think any sockets would have an open.
Turns out AF_UNIX sockets can have an open when they are bound to the
filesystem namespace. This patch adds a new SOCK_FILE__OPEN permission.
It's safe to add this as the open perms are already predicated on
capabilities and capabilities means we have unknown perm handling so
systems should be as backwards compatible as the policy wants them to
be.
https://bugzilla.redhat.com/show_bug.cgi?id=475224
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
The following patch (against 2.6.29rc5) fixes a few issues in the
smack/netlabel "unlabeled host support" functionnality that was added in
2.6.29rc. It should go in before -final.
1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label),
preventing 'tagged' tasks to access Internet (many systems drop packets with
IP options)
2) netmasks were not handled correctly, they were stored in a way _not
equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24,
/32 masks but not other masks)
3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not
done), so there could have been different list entries for the same IP
prefix; if those entries had different labels, well ...
4) they were not sorted
1) 2) 3) are bugs, 4) is a more cosmetic issue.
The patch :
-creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr,
-sorted by netmask length
-use the new sorted nature of smack_netlbladdrs list to simplify
smack_host_label : the first match _will_ be the more specific
-corrects endianness issues in smk_write_netlbladdr & netlbladdr_seq_show
Signed-off-by: <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The following patch (against 2.6.29rc5) fixes a few issues in the
smack/netlabel "unlabeled host support" functionnality that was added in
2.6.29rc. It should go in before -final.
1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label),
preventing 'tagged' tasks to access Internet (many systems drop packets with
IP options)
2) netmasks were not handled correctly, they were stored in a way _not
equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24,
/32 masks but not other masks)
3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not
done), so there could have been different list entries for the same IP
prefix; if those entries had different labels, well ...
4) they were not sorted
1) 2) 3) are bugs, 4) is a more cosmetic issue.
The patch :
-creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr,
-sorted by netmask length
-use the new sorted nature of smack_netlbladdrs list to simplify
smack_host_label : the first match _will_ be the more specific
-corrects endianness issues in smk_write_netlbladdr & netlbladdr_seq_show
Signed-off-by: <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Rick McNeal from LSI identified a panic in selinux_netlbl_inode_permission()
caused by a certain sequence of SUNRPC operations. The problem appears to be
due to the lack of NULL pointer checking in the function; this patch adds the
pointer checks so the function will exit safely in the cases where the socket
is not completely initialized.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Restrict the /proc/keys and /proc/key-users output to keys
belonging to the same user namespace as the reading task.
We may want to make this more complicated - so that any
keys in a user-namespace which is belongs to the reading
task are also shown. But let's see if anyone wants that
first.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
When listing keys, do not return keys belonging to the
same uid in another user namespace. Otherwise uid 500
in another user namespace will return keyrings called
uid.500 for another user namespace.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
If a key is owned by another user namespace, then treat the
key as though it is owned by both another uid and gid.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
per-uid keys were looked by uid only. Use the user namespace
to distinguish the same uid in different namespaces.
This does not address key_permission. So a task can for instance
try to join a keyring owned by the same uid in another namespace.
That will be handled by a separate patch.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
At some point we (okay, I) managed to break the ability for users to use the
setsockopt() syscall to set IPv4 options when NetLabel was not active on the
socket in question. The problem was noticed by someone trying to use the
"-R" (record route) option of ping:
# ping -R 10.0.0.1
ping: record route: No message of desired type
The solution is relatively simple, we catch the unlabeled socket case and
clear the error code, allowing the operation to succeed. Please note that we
still deny users the ability to override IPv4 options on socket's which have
NetLabel labeling active; this is done to ensure the labeling remains intact.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Based on Andrew Morton's comments:
- add missing locks around radix_tree_lookup in ima_iint_insert()
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
tomoyo_realpath_init() is unconditionally called by security_initcall().
But nobody will use realpath related functions if TOMOYO is not registered.
So, let tomoyo_init() call tomoyo_realpath_init().
This patch saves 4KB of memory allocation if TOMOYO is not registered.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Fix/add kernel-doc notation and fix typos in security/smack/.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
We do not need O(1) access to the tail of the avc cache lists and so we are
wasting lots of space using struct list_head instead of struct hlist_head.
This patch converts the avc cache to use hlists in which there is a single
pointer from the head which saves us about 4k of global memory.
Resulted in about a 1.5% decrease in time spent in avc_has_perm_noaudit based
on oprofile sampling of tbench. Although likely within the noise....
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The code making use of struct avc_cache was not easy to read thanks to liberal
use of &avc_cache.{slots_lock,slots}[hvalue] throughout. This patch simply
creates local pointers and uses those instead of the long global names.
Signed-off-by: Eric Paris <eparis@redhat.com>
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>
we are often needlessly jumping through hoops when it comes to avd
entries in avc_has_perm_noaudit and we have extra initialization and memcpy
which are just wasting performance. Try to clean the function up a bit.
This patch resulted in a 13% drop in time spent in avc_has_perm_noaudit in my
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>
Currently SELinux code has an atomic which was intended to track how many
times an avc entry was used and to evict entries when they haven't been
used recently. Instead we never let this atomic get above 1 and evict when
it is first checked for eviction since it hits zero. This is a total waste
of time so I'm completely dropping ae.used.
This change resulted in about a 3% faster avc_has_perm_noaudit when running
oprofile against 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>
The avc update node callbacks do not check the seqno of the caller with the
seqno of the node found. It is possible that a policy change could happen
(although almost impossibly unlikely) in which a permissive or
permissive_domain decision is not valid for the entry found. Simply pass
and check that the seqno of the caller and the seqno of the node found
match.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
When a context is pulled in from disk we don't know that it is null
terminated. This patch forecebly null terminates contexts when we pull
them from disk.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Currently when an inode is read into the kernel with an invalid label
string (can often happen with removable media) we output a string like:
SELinux: inode_doinit_with_dentry: context_to_sid([SOME INVALID LABEL])
returned -22 dor dev=[blah] ino=[blah]
Which is all but incomprehensible to all but a couple of us. Instead, on
EINVAL only, I plan to output a much more user friendly string and I plan to
ratelimit the printk since many of these could be generated very rapidly.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
For cleanliness and efficiency remove all calls to secondary-> and instead
call capabilities code directly. capabilities are the only module that
selinux stacks with and so the code should not indicate that other stacking
might be possible.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
IMA_LSM_RULES requires AUDIT. This is automatic if SECURITY_SELINUX=y
but not when SECURITY_SMACK=y (and SECURITY_SELINUX=n), so make the
dependency explicit. This fixes the following build error:
security/integrity/ima/ima_policy.c:111:error: implicit declaration of function 'security_audit_rule_match'
security/integrity/ima/ima_policy.c:230:error: implicit declaration of function 'security_audit_rule_init'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
LSMs need to be linked before root_plug to ensure the security=
boot parameter works with them. Do this for Tomoyo.
(root_plug probably needs to be taken out and shot at some point,
too).
Signed-off-by: James Morris <jmorris@namei.org>
TOMOYO uses LSM hooks for pathname based access control and securityfs support.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
DAC's permissions and TOMOYO's permissions are not one-to-one mapping.
Regarding DAC, there are "read", "write", "execute" permissions.
Regarding TOMOYO, there are "allow_read", "allow_write", "allow_read/write",
"allow_execute", "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
"allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
"allow_truncate", "allow_symlink", "allow_rewrite", "allow_link",
"allow_rename" permissions.
+----------------------------------+----------------------------------+
| requested operation | required TOMOYO's permission |
+----------------------------------+----------------------------------+
| sys_open(O_RDONLY) | allow_read |
+----------------------------------+----------------------------------+
| sys_open(O_WRONLY) | allow_write |
+----------------------------------+----------------------------------+
| sys_open(O_RDWR) | allow_read/write |
+----------------------------------+----------------------------------+
| open_exec() from do_execve() | allow_execute |
+----------------------------------+----------------------------------+
| open_exec() from !do_execve() | allow_read |
+----------------------------------+----------------------------------+
| sys_read() | (none) |
+----------------------------------+----------------------------------+
| sys_write() | (none) |
+----------------------------------+----------------------------------+
| sys_mmap() | (none) |
+----------------------------------+----------------------------------+
| sys_uselib() | allow_read |
+----------------------------------+----------------------------------+
| sys_open(O_CREAT) | allow_create |
+----------------------------------+----------------------------------+
| sys_open(O_TRUNC) | allow_truncate |
+----------------------------------+----------------------------------+
| sys_truncate() | allow_truncate |
+----------------------------------+----------------------------------+
| sys_ftruncate() | allow_truncate |
+----------------------------------+----------------------------------+
| sys_open() without O_APPEND | allow_rewrite |
+----------------------------------+----------------------------------+
| setfl() without O_APPEND | allow_rewrite |
+----------------------------------+----------------------------------+
| sys_sysctl() for writing | allow_write |
+----------------------------------+----------------------------------+
| sys_sysctl() for reading | allow_read |
+----------------------------------+----------------------------------+
| sys_unlink() | allow_unlink |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFREG) | allow_create |
+----------------------------------+----------------------------------+
| sys_mknod(0) | allow_create |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFIFO) | allow_mkfifo |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFSOCK) | allow_mksock |
+----------------------------------+----------------------------------+
| sys_bind(AF_UNIX) | allow_mksock |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFBLK) | allow_mkblock |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFCHR) | allow_mkchar |
+----------------------------------+----------------------------------+
| sys_symlink() | allow_symlink |
+----------------------------------+----------------------------------+
| sys_mkdir() | allow_mkdir |
+----------------------------------+----------------------------------+
| sys_rmdir() | allow_rmdir |
+----------------------------------+----------------------------------+
| sys_link() | allow_link |
+----------------------------------+----------------------------------+
| sys_rename() | allow_rename |
+----------------------------------+----------------------------------+
TOMOYO requires "allow_execute" permission of a pathname passed to do_execve()
but does not require "allow_read" permission of that pathname.
Let's consider 3 patterns (statically linked, dynamically linked,
shell script). This description is to some degree simplified.
$ cat hello.c
#include <stdio.h>
int main() {
printf("Hello\n");
return 0;
}
$ cat hello.sh
#! /bin/sh
echo "Hello"
$ gcc -static -o hello-static hello.c
$ gcc -o hello-dynamic hello.c
$ chmod 755 hello.sh
Case 1 -- Executing hello-static from bash.
(1) The bash process calls fork() and the child process requests
do_execve("hello-static").
(2) The kernel checks "allow_execute hello-static" from "bash" domain.
(3) The kernel calculates "bash hello-static" as the domain to transit to.
(4) The kernel overwrites the child process by "hello-static".
(5) The child process transits to "bash hello-static" domain.
(6) The "hello-static" starts and finishes.
Case 2 -- Executing hello-dynamic from bash.
(1) The bash process calls fork() and the child process requests
do_execve("hello-dynamic").
(2) The kernel checks "allow_execute hello-dynamic" from "bash" domain.
(3) The kernel calculates "bash hello-dynamic" as the domain to transit to.
(4) The kernel checks "allow_read ld-linux.so" from "bash hello-dynamic"
domain. I think permission to access ld-linux.so should be charged
hello-dynamic program, for "hello-dynamic needs ld-linux.so" is not
a fault of bash program.
(5) The kernel overwrites the child process by "hello-dynamic".
(6) The child process transits to "bash hello-dynamic" domain.
(7) The "hello-dynamic" starts and finishes.
Case 3 -- Executing hello.sh from bash.
(1) The bash process calls fork() and the child process requests
do_execve("hello.sh").
(2) The kernel checks "allow_execute hello.sh" from "bash" domain.
(3) The kernel calculates "bash hello.sh" as the domain to transit to.
(4) The kernel checks "allow_read /bin/sh" from "bash hello.sh" domain.
I think permission to access /bin/sh should be charged hello.sh program,
for "hello.sh needs /bin/sh" is not a fault of bash program.
(5) The kernel overwrites the child process by "/bin/sh".
(6) The child process transits to "bash hello.sh" domain.
(7) The "/bin/sh" requests open("hello.sh").
(8) The kernel checks "allow_read hello.sh" from "bash hello.sh" domain.
(9) The "/bin/sh" starts and finishes.
Whether a file is interpreted as a program or not depends on an application.
The kernel cannot know whether the file is interpreted as a program or not.
Thus, TOMOYO treats "hello-static" "hello-dynamic" "ld-linux.so" "hello.sh"
"/bin/sh" equally as merely files; no distinction between executable and
non-executable. Therefore, TOMOYO doesn't check DAC's execute permission.
TOMOYO checks "allow_read" permission instead.
Calling do_execve() is a bold gesture that an old program's instance (i.e.
current process) is ready to be overwritten by a new program and is ready to
transfer control to the new program. To split purview of programs, TOMOYO
requires "allow_execute" permission of the new program against the old
program's instance and performs domain transition. If do_execve() succeeds,
the old program is no longer responsible against the consequence of the new
program's behavior. Only the new program is responsible for all consequences.
But TOMOYO doesn't require "allow_read" permission of the new program.
If TOMOYO requires "allow_read" permission of the new program, TOMOYO will
allow an attacker (who hijacked the old program's instance) to open the new
program and steal data from the new program. Requiring "allow_read" permission
will widen purview of the old program.
Not requiring "allow_read" permission of the new program against the old
program's instance is my design for reducing purview of the old program.
To be able to know whether the current process is in do_execve() or not,
I want to add in_execve flag to "task_struct".
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This file controls domain creation/deletion/transition.
Every process belongs to a domain in TOMOYO Linux.
Domain transition occurs when execve(2) is called
and the domain is expressed as 'process invocation history',
such as '<kernel> /sbin/init /etc/init.d/rc'.
Domain information is stored in current->cred->security field.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This file controls file related operations of TOMOYO Linux.
tomoyo/tomoyo.c calls the following six functions in this file.
Each function handles the following access types.
* tomoyo_check_file_perm
sysctl()'s "read" and "write".
* tomoyo_check_exec_perm
"execute".
* tomoyo_check_open_permission
open(2) for "read" and "write".
* tomoyo_check_1path_perm
"create", "unlink", "mkdir", "rmdir", "mkfifo",
"mksock", "mkblock", "mkchar", "truncate" and "symlink".
* tomoyo_check_2path_perm
"rename" and "unlink".
* tomoyo_check_rewrite_permission
"rewrite".
("rewrite" are operations which may lose already recorded data of a file,
i.e. open(!O_APPEND) || open(O_TRUNC) || truncate() || ftruncate())
The functions which actually checks ACLs are the following three functions.
Each function handles the following access types.
ACL directive is expressed by "allow_<access type>".
* tomoyo_check_file_acl
Open() operation and execve() operation.
("read", "write", "read/write" and "execute")
* tomoyo_check_single_write_acl
Directory modification operations with 1 pathname.
("create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock",
"mkblock", "mkchar", "truncate", "symlink" and "rewrite")
* tomoyo_check_double_write_acl
Directory modification operations with 2 pathname.
("link" and "rename")
Also, this file contains handlers of some utility directives
for file related operations.
* "allow_read": specifies globally (for all domains) readable files.
* "path_group": specifies pathname macro.
* "deny_rewrite": restricts rewrite operation.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This file contains common functions (e.g. policy I/O, pattern matching).
-------------------- About pattern matching --------------------
Since TOMOYO Linux is a name based access control, TOMOYO Linux seriously
considers "safe" string representation.
TOMOYO Linux's string manipulation functions make reviewers feel crazy,
but there are reasons why TOMOYO Linux needs its own string manipulation
functions.
----- Part 1 : preconditions -----
People definitely want to use wild card.
To support pattern matching, we have to support wild card characters.
In a typical Linux system, filenames are likely consists of only alphabets,
numbers, and some characters (e.g. + - ~ . / ).
But theoretically, the Linux kernel accepts all characters but NUL character
(which is used as a terminator of a string).
Some Linux systems can have filenames which contain * ? ** etc.
Therefore, we have to somehow modify string so that we can distinguish
wild card characters and normal characters.
It might be possible for some application's configuration files to restrict
acceptable characters.
It is impossible for kernel to restrict acceptable characters.
We can't accept approaches which will cause troubles for applications.
----- Part 2 : commonly used approaches -----
Text formatted strings separated by space character (0x20) and new line
character (0x0A) is more preferable for users over array of NUL-terminated
string.
Thus, people use text formatted configuration files separated by space
character and new line.
We sometimes need to handle non-printable characters.
Thus, people use \ character (0x5C) as escape character and represent
non-printable characters using octal or hexadecimal format.
At this point, we remind (at least) 3 approaches.
(1) Shell glob style expression
(2) POSIX regular expression (UNIX style regular expression)
(3) Maverick wild card expression
On the surface, (1) and (2) sound good choices. But they have a big pitfall.
All meta-characters in (1) and (2) are legal characters for representing
a pathname, and users easily write incorrect expression. What is worse, users
unlikely notice incorrect expressions because characters used for regular
pathnames unlikely contain meta-characters. This incorrect use of
meta-characters in pathname representation reveals vulnerability
(e.g. unexpected results) only when irregular pathname is specified.
The authors of TOMOYO Linux think that approaches which adds some character
for interpreting meta-characters as normal characters (i.e. (1) and (2)) are
not suitable for security use.
Therefore, the authors of TOMOYO Linux propose (3).
----- Part 3: consideration points -----
We need to solve encoding problem.
A single character can be represented in several ways using encodings.
For Japanese language, there are "ShiftJIS", "ISO-2022-JP", "EUC-JP",
"UTF-8" and more.
Some languages (e.g. Japanese language) supports multi-byte characters
(where a single character is represented using several bytes).
Some multi-byte characters may match the escape character.
For Japanese language, some characters in "ShiftJIS" encoding match
\ character, and bothering Web's CGI developers.
It is important that the kernel string is not bothered by encoding problem.
Linus said, "I really would expect that kernel strings don't have
an encoding. They're just C strings: a NUL-terminated stream of bytes."
http://lkml.org/lkml/2007/11/6/142
Yes. The kernel strings are just C strings.
We are talking about how to store and carry "kernel strings" safely.
If we store "kernel string" into policy file as-is, the "kernel string" will
be interpreted differently depending on application's encoding settings.
One application may interpret "kernel string" as "UTF-8",
another application may interpret "kernel string" as "ShiftJIS".
Therefore, we propose to represent strings using ASCII encoding.
In this way, we are no longer bothered by encoding problems.
We need to avoid information loss caused by display.
It is difficult to input and display non-printable characters, but we have to
be able to handle such characters because the kernel string is a C string.
If we use only ASCII printable characters (from 0x21 to 0x7E) and space
character (0x20) and new line character (0x0A), it is easy to input from
keyboard and display on all terminals which is running Linux.
Therefore, we propose to represent strings using only characters which value
is one of "from 0x21 to 0x7E", "0x20", "0x0A".
We need to consider ease of splitting strings from a line.
If we use an approach which uses "\ " for representing a space character
within a string, we have to count the string from the beginning to check
whether this space character is accompanied with \ character or not.
As a result, we cannot monotonically split a line using space character.
If we use an approach which uses "\040" for representing a space character
within a string, we can monotonically split a line using space character.
If we use an approach which uses NUL character as a delimiter, we cannot
use string manipulation functions for splitting strings from a line.
Therefore, we propose that we represent space character as "\040".
We need to avoid wrong designations (incorrect use of special characters).
Not all users can understand and utilize POSIX's regular expressions
correctly and perfectly.
If a character acts as a wild card by default, the user will get unexpected
result if that user didn't know the meaning of that character.
Therefore, we propose that all characters but \ character act as
a normal character and let the user add \ character to make a character
act as a wild card.
In this way, users needn't to know all wild card characters beforehand.
They can learn when they encountered an unseen wild card character
for their first time.
----- Part 4: supported wild card expressions -----
At this point, we have wild card expressions listed below.
+-----------+--------------------------------------------------------------+
| Wild card | Meaning and example |
+-----------+--------------------------------------------------------------+
| \* | More than or equals to 0 character other than '/'. |
| | /var/log/samba/\* |
+-----------+--------------------------------------------------------------+
| \@ | More than or equals to 0 character other than '/' or '.'. |
| | /var/www/html/\@.html |
+-----------+--------------------------------------------------------------+
| \? | 1 byte character other than '/'. |
| | /tmp/mail.\?\?\?\?\?\? |
+-----------+--------------------------------------------------------------+
| \$ | More than or equals to 1 decimal digit. |
| | /proc/\$/cmdline |
+-----------+--------------------------------------------------------------+
| \+ | 1 decimal digit. |
| | /var/tmp/my_work.\+ |
+-----------+--------------------------------------------------------------+
| \X | More than or equals to 1 hexadecimal digit. |
| | /var/tmp/my-work.\X |
+-----------+--------------------------------------------------------------+
| \x | 1 hexadecimal digit. |
| | /tmp/my-work.\x |
+-----------+--------------------------------------------------------------+
| \A | More than or equals to 1 alphabet character. |
| | /var/log/my-work/\$-\A-\$.log |
+-----------+--------------------------------------------------------------+
| \a | 1 alphabet character. |
| | /home/users/\a/\*/public_html/\*.html |
+-----------+--------------------------------------------------------------+
| \- | Pathname subtraction operator. |
| | +---------------------+------------------------------------+ |
| | | Example | Meaning | |
| | +---------------------+------------------------------------+ |
| | | /etc/\* | All files in /etc/ directory. | |
| | +---------------------+------------------------------------+ |
| | | /etc/\*\-\*shadow\* | /etc/\* other than /etc/\*shadow\* | |
| | +---------------------+------------------------------------+ |
| | | /\*\-proc\-sys/ | /\*/ other than /proc/ /sys/ | |
| | +---------------------+------------------------------------+ |
+-----------+--------------------------------------------------------------+
+----------------+---------------------------------------------------------+
| Representation | Meaning and example |
+----------------+---------------------------------------------------------+
| \\ | backslash character itself. |
+----------------+---------------------------------------------------------+
| \ooo | 1 byte character. |
| | ooo is 001 <= ooo <= 040 || 177 <= ooo <= 377. |
| | |
| | \040 for space character. |
| | \177 for del character. |
| | |
+----------------+---------------------------------------------------------+
----- Part 5: Advantages -----
We can obtain extensibility.
Since our proposed approach adds \ to a character to interpret as a wild
card, we can introduce new wild card in future while maintaining backward
compatibility.
We can process monotonically.
Since our proposed approach separates strings using a space character,
we can split strings using existing string manipulation functions.
We can reliably analyze access logs.
It is guaranteed that a string doesn't contain space character (0x20) and
new line character (0x0A).
It is guaranteed that a string won't be converted by FTP and won't be damaged
by a terminal's settings.
It is guaranteed that a string won't be affected by encoding converters
(except encodings which insert NUL character (e.g. UTF-16)).
----- Part 6: conclusion -----
TOMOYO Linux is using its own encoding with reasons described above.
There is a disadvantage that we need to introduce a series of new string
manipulation functions. But TOMOYO Linux's encoding is useful for all users
(including audit and AppArmor) who want to perform pattern matching and
safely exchange string information between the kernel and the userspace.
-------------------- About policy interface --------------------
TOMOYO Linux creates the following files on securityfs (normally
mounted on /sys/kernel/security) as interfaces between kernel and
userspace. These files are for TOMOYO Linux management tools *only*,
not for general programs.
* profile
* exception_policy
* domain_policy
* manager
* meminfo
* self_domain
* version
* .domain_status
* .process_status
** /sys/kernel/security/tomoyo/profile **
This file is used to read or write profiles.
"profile" means a running mode of process. A profile lists up
functions and their modes in "$number-$variable=$value" format. The
$number is profile number between 0 and 255. Each domain is assigned
one profile. To assign profile to domains, use "ccs-setprofile" or
"ccs-editpolicy" or "ccs-loadpolicy" commands.
(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/profile
0-COMMENT=-----Disabled Mode-----
0-MAC_FOR_FILE=disabled
0-MAX_ACCEPT_ENTRY=2048
0-TOMOYO_VERBOSE=disabled
1-COMMENT=-----Learning Mode-----
1-MAC_FOR_FILE=learning
1-MAX_ACCEPT_ENTRY=2048
1-TOMOYO_VERBOSE=disabled
2-COMMENT=-----Permissive Mode-----
2-MAC_FOR_FILE=permissive
2-MAX_ACCEPT_ENTRY=2048
2-TOMOYO_VERBOSE=enabled
3-COMMENT=-----Enforcing Mode-----
3-MAC_FOR_FILE=enforcing
3-MAX_ACCEPT_ENTRY=2048
3-TOMOYO_VERBOSE=enabled
- MAC_FOR_FILE:
Specifies access control level regarding file access requests.
- MAX_ACCEPT_ENTRY:
Limits the max number of ACL entries that are automatically appended
during learning mode. Default is 2048.
- TOMOYO_VERBOSE:
Specifies whether to print domain policy violation messages or not.
** /sys/kernel/security/tomoyo/manager **
This file is used to read or append the list of programs or domains
that can write to /sys/kernel/security/tomoyo interface. By default,
only processes with both UID = 0 and EUID = 0 can modify policy via
/sys/kernel/security/tomoyo interface. You can use keyword
"manage_by_non_root" to allow policy modification by non root user.
(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/manager
/usr/lib/ccs/loadpolicy
/usr/lib/ccs/editpolicy
/usr/lib/ccs/setlevel
/usr/lib/ccs/setprofile
/usr/lib/ccs/ld-watch
/usr/lib/ccs/ccs-queryd
** /sys/kernel/security/tomoyo/exception_policy **
This file is used to read and write system global settings. Each line
has a directive and operand pair. Directives are listed below.
- initialize_domain:
To initialize domain transition when specific program is executed,
use initialize_domain directive.
* initialize_domain "program" from "domain"
* initialize_domain "program" from "the last program part of domain"
* initialize_domain "program"
If the part "from" and after is not given, the entry is applied to
all domain. If the "domain" doesn't start with "<kernel>", the entry
is applied to all domain whose domainname ends with "the last program
part of domain".
This directive is intended to aggregate domain transitions for daemon
program and program that are invoked by the kernel on demand, by
transiting to different domain.
- keep_domain
To prevent domain transition when program is executed from specific
domain, use keep_domain directive.
* keep_domain "program" from "domain"
* keep_domain "program" from "the last program part of domain"
* keep_domain "domain"
* keep_domain "the last program part of domain"
If the part "from" and before is not given, this entry is applied to
all program. If the "domain" doesn't start with "<kernel>", the entry
is applied to all domain whose domainname ends with "the last program
part of domain".
This directive is intended to reduce total number of domains and
memory usage by suppressing unneeded domain transitions.
To declare domain keepers, use keep_domain directive followed by
domain definition.
Any process that belongs to any domain declared with this directive,
the process stays at the same domain unless any program registered
with initialize_domain directive is executed.
In order to control domain transition in detail, you can use
no_keep_domain/no_initialize_domain keywrods.
- alias:
To allow executing programs using the name of symbolic links, use
alias keyword followed by dereferenced pathname and reference
pathname. For example, /sbin/pidof is a symbolic link to
/sbin/killall5 . In normal case, if /sbin/pidof is executed, the
domain is defined as if /sbin/killall5 is executed. By specifying
"alias /sbin/killall5 /sbin/pidof", you can run /sbin/pidof in the
domain for /sbin/pidof .
(Example)
alias /sbin/killall5 /sbin/pidof
- allow_read:
To grant unconditionally readable permissions, use allow_read keyword
followed by canonicalized file. This keyword is intended to reduce
size of domain policy by granting read access to library files such
as GLIBC and locale files. Exception is, if ignore_global_allow_read
keyword is given to a domain, entries specified by this keyword are
ignored.
(Example)
allow_read /lib/libc-2.5.so
- file_pattern:
To declare pathname pattern, use file_pattern keyword followed by
pathname pattern. The pathname pattern must be a canonicalized
Pathname. This keyword is not applicable to neither granting execute
permissions nor domain definitions.
For example, canonicalized pathname that contains a process ID
(i.e. /proc/PID/ files) needs to be grouped in order to make access
control work well.
(Example)
file_pattern /proc/\$/cmdline
- path_group
To declare pathname group, use path_group keyword followed by name of
the group and pathname pattern. For example, if you want to group all
files under home directory, you can define
path_group HOME-DIR-FILE /home/\*/\*
path_group HOME-DIR-FILE /home/\*/\*/\*
path_group HOME-DIR-FILE /home/\*/\*/\*/\*
in the exception policy and use like
allow_read @HOME-DIR-FILE
to grant file access permission.
- deny_rewrite:
To deny overwriting already written contents of file (such as log
files) by default, use deny_rewrite keyword followed by pathname
pattern. Files whose pathname match the patterns are not permitted to
open for writing without append mode or truncate unless the pathnames
are explicitly granted using allow_rewrite keyword in domain policy.
(Example)
deny_rewrite /var/log/\*
- aggregator
To deal multiple programs as a single program, use aggregator keyword
followed by name of original program and aggregated program. This
keyword is intended to aggregate similar programs.
For example, /usr/bin/tac and /bin/cat are similar. By specifying
"aggregator /usr/bin/tac /bin/cat", you can run /usr/bin/tac in the
domain for /bin/cat .
For example, /usr/sbin/logrotate for Fedora Core 3 generates programs
like /tmp/logrotate.\?\?\?\?\?\? and run them, but TOMOYO Linux
doesn't allow using patterns for granting execute permission and
defining domains. By specifying
"aggregator /tmp/logrotate.\?\?\?\?\?\? /tmp/logrotate.tmp", you can
run /tmp/logrotate.\?\?\?\?\?\? as if /tmp/logrotate.tmp is running.
** /sys/kernel/security/tomoyo/domain_policy **
This file contains definition of all domains and permissions that are
granted to each domain.
Lines from the next line to a domain definition ( any lines starting
with "<kernel>") to the previous line to the next domain definitions
are interpreted as access permissions for that domain.
** /sys/kernel/security/tomoyo/meminfo **
This file is to show the total RAM used to keep policy in the kernel
by TOMOYO Linux in bytes.
(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/meminfo
Shared: 61440
Private: 69632
Dynamic: 768
Total: 131840
You can set memory quota by writing to this file.
(Example)
[root@tomoyo]# echo Shared: 2097152 > /sys/kernel/security/tomoyo/meminfo
[root@tomoyo]# echo Private: 2097152 > /sys/kernel/security/tomoyo/meminfo
** /sys/kernel/security/tomoyo/self_domain **
This file is to show the name of domain the caller process belongs to.
(Example)
[root@etch]# cat /sys/kernel/security/tomoyo/self_domain
<kernel> /usr/sbin/sshd /bin/zsh /bin/cat
** /sys/kernel/security/tomoyo/version **
This file is used for getting TOMOYO Linux's version.
(Example)
[root@etch]# cat /sys/kernel/security/tomoyo/version
2.2.0-pre
** /sys/kernel/security/tomoyo/.domain_status **
This is a view (of a DBMS) that contains only profile number and
domainnames of domain so that "ccs-setprofile" command can do
line-oriented processing easily.
** /sys/kernel/security/tomoyo/.process_status **
This file is used by "ccs-ccstree" command to show "list of processes
currently running" and "domains which each process belongs to" and
"profile number which the domain is currently assigned" like "pstree"
command. This file is writable by programs that aren't registered as
policy manager.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
TOMOYO Linux performs pathname based access control.
To remove factors that make pathname based access control difficult
(e.g. symbolic links, "..", "//" etc.), TOMOYO Linux derives realpath
of requested pathname from "struct dentry" and "struct vfsmount".
The maximum length of string data is limited to 4000 including trailing '\0'.
Since TOMOYO Linux uses '\ooo' style representation for non ASCII printable
characters, maybe TOMOYO Linux should be able to support 16336 (which means
(NAME_MAX * (PATH_MAX / (NAME_MAX + 1)) * 4 + (PATH_MAX / (NAME_MAX + 1)))
including trailing '\0'), but I think 4000 is enough for practical use.
TOMOYO uses only 0x21 - 0x7E (as printable characters) and 0x20 (as word
delimiter) and 0x0A (as line delimiter).
0x01 - 0x20 and 0x80 - 0xFF is handled in \ooo style representation.
The reason to use \ooo is to guarantee that "%s" won't damage logs.
Userland program can request
open("/tmp/file granted.\nAccess /tmp/file ", O_WRONLY | O_CREAT, 0600)
and logging such crazy pathname using "Access %s denied.\n" format will cause
"fabrication of logs" like
Access /tmp/file granted.
Access /tmp/file denied.
TOMOYO converts such characters to \ooo so that the logs will become
Access /tmp/file\040granted.\012Access\040/tmp/file denied.
and the administrator can read the logs safely using /bin/cat .
Likewise, a crazy request like
open("/tmp/\x01\x02\x03\x04\x05\x06\x07\x08\x09", O_WRONLY | O_CREAT, 0600)
will be processed safely by converting to
Access /tmp/\001\002\003\004\005\006\007\010\011 denied.
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Based on discussions on linux-audit, as per Steve Grubb's request
http://lkml.org/lkml/2009/2/6/269, the following changes were made:
- forced audit result to be either 0 or 1.
- made template names const
- Added new stand-alone message type: AUDIT_INTEGRITY_RULE
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
The number of calls to ima_path_check()/ima_file_free()
should be balanced. An extra call to fput(), indicates
the file could have been accessed without first being
measured.
Although f_count is incremented/decremented in places other
than fget/fput, like fget_light/fput_light and get_file, the
current task must already hold a file refcnt. The call to
__fput() is delayed until the refcnt becomes 0, resulting
in ima_file_free() flagging any changes.
- add hook to increment opencount for IPC shared memory(SYSV),
shmat files, and /dev/zero
- moved NULL iint test in opencount_get()
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Sequentialize access to the policy file
- permit multiple attempts to replace default policy with a valid policy
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Support for a user loadable policy through securityfs
with support for LSM specific policy data.
- free invalid rule in ima_parse_add_rule()
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Make the measurement lists available through securityfs.
- removed test for NULL return code from securityfs_create_file/dir
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
IMA provides hardware (TPM) based measurement and attestation for
file measurements. As the Trusted Computing (TPM) model requires,
IMA measures all files before they are accessed in any way (on the
integrity_bprm_check, integrity_path_check and integrity_file_mmap
hooks), and commits the measurements to the TPM. Once added to the
TPM, measurements can not be removed.
In addition, IMA maintains a list of these file measurements, which
can be used to validate the aggregate value stored in the TPM. The
TPM can sign these measurements, and thus the system can prove, to
itself and to a third party, the system's integrity in a way that
cannot be circumvented by malicious or compromised software.
- alloc ima_template_entry before calling ima_store_template()
- log ima_add_boot_aggregate() failure
- removed unused IMA_TEMPLATE_NAME_LEN
- replaced hard coded string length with #define name
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
If there is an error creating a file through securityfs_create_file,
NULL is not returned, rather the error is propagated.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove SELinux hooks which do nothing except defer to the capabilites
hooks (or in one case, replicates the function).
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Remove secondary ops call to shm_shmat, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to unix_stream_connect, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to task_kill, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to task_setrlimit, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove unused cred_commit hook from SELinux. This
currently calls into the capabilities hook, which is a noop.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to task_create, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to file_mprotect, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to inode_setattr, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to inode_permission, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to inode_follow_link, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to inode_mknod, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to inode_unlink, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to inode_link, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to sb_umount, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to sb_mount, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to bprm_committed_creds, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove secondary ops call to bprm_committing_creds, which is
a noop in capabilities.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Remove unused bprm_check_security hook from SELinux. This
currently calls into the capabilities hook, which is a noop.
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Given just how hard it is to find the code that uses MAY_APPEND
it's probably not a big surprise that this went unnoticed for so
long. The Smack rules loading code is incorrectly setting the
MAY_READ bit when MAY_APPEND is requested.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Context mounts and genfs labeled file systems behave differently with respect to
setting file system labels. This patch brings genfs labeled file systems in line
with context mounts in that setxattr calls to them should return EOPNOTSUPP and
fscreate calls will be ignored.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@macbook.localdomain>
There is no easy way to tell if a file system supports SELinux security labeling.
Because of this a new flag is being added to the super block security structure
to indicate that the particular super block supports labeling. This flag is set
for file systems using the xattr, task, and transition labeling methods unless
that behavior is overridden by context mounts.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@macbook.localdomain>
The super block security structure currently has three fields for what are
essentially flags. The flags field is used for mount options while two other
char fields are used for initialization and proc flags. These latter two fields are
essentially bit fields since the only used values are 0 and 1. These fields
have been collapsed into the flags field and new bit masks have been added for
them. The code is also fixed to work with these new flags.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@macbook.localdomain>
The devcgroup_inode_permission() hook in the devices whitelist cgroup has
always bypassed access checks on fifos. But the mknod hook did not. The
devices whitelist is only about block and char devices, and fifos can't
even be added to the whitelist, so fifos can't be created at all except by
tasks which have 'a' in their whitelist (meaning they have access to all
devices).
Fix the behavior by bypassing access checks to mkfifo.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: James Morris <jmorris@namei.org>
Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: <stable@kernel.org> [2.6.27.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should use list_for_each_entry_rcu in RCU read site.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a regression in cap_capable() due to:
commit 3b11a1dece
Author: David Howells <dhowells@redhat.com>
Date: Fri Nov 14 10:39:26 2008 +1100
CRED: Differentiate objective and effective subjective credentials on a task
The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.
There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.
Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds. However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.
One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.
The affected capability check is in generic_permission():
if (!(mask & MAY_EXEC) || execute_ok(inode))
if (capable(CAP_DAC_OVERRIDE))
return 0;
This change passes the set of credentials to be tested down into the commoncap
and SELinux code. The security functions called by capable() and
has_capability() select the appropriate set of credentials from the process
being checked.
This can be tested by compiling the following program from the XFS testsuite:
/*
* t_access_root.c - trivial test program to show permission bug.
*
* Written by Michael Kerrisk - copyright ownership not pursued.
* Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
*/
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"
static void
errExit(char *msg)
{
perror(msg);
exit(EXIT_FAILURE);
} /* errExit */
static void
accessTest(char *file, int mask, char *mstr)
{
printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */
int
main(int argc, char *argv[])
{
int fd, perm, uid, gid;
char *testpath;
char cmd[PATH_MAX + 20];
testpath = (argc > 1) ? argv[1] : TESTPATH;
perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
uid = (argc > 3) ? atoi(argv[3]) : UID;
gid = (argc > 4) ? atoi(argv[4]) : GID;
unlink(testpath);
fd = open(testpath, O_RDWR | O_CREAT, 0);
if (fd == -1) errExit("open");
if (fchown(fd, uid, gid) == -1) errExit("fchown");
if (fchmod(fd, perm) == -1) errExit("fchmod");
close(fd);
snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
system(cmd);
if (seteuid(uid) == -1) errExit("seteuid");
accessTest(testpath, 0, "0");
accessTest(testpath, R_OK, "R_OK");
accessTest(testpath, W_OK, "W_OK");
accessTest(testpath, X_OK, "X_OK");
accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");
exit(EXIT_SUCCESS);
} /* main */
This can be run against an Ext3 filesystem as well as against an XFS
filesystem. If successful, it will show:
[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
access(/tmp/xxx, 0) returns 0
access(/tmp/xxx, R_OK) returns 0
access(/tmp/xxx, W_OK) returns 0
access(/tmp/xxx, X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK) returns 0
access(/tmp/xxx, R_OK | X_OK) returns -1
access(/tmp/xxx, W_OK | X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1
If unsuccessful, it will show:
[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
access(/tmp/xxx, 0) returns 0
access(/tmp/xxx, R_OK) returns -1
access(/tmp/xxx, W_OK) returns -1
access(/tmp/xxx, X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK) returns -1
access(/tmp/xxx, R_OK | X_OK) returns -1
access(/tmp/xxx, W_OK | X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1
I've also tested the fix with the SELinux and syscalls LTP testsuites.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
