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* keys: Handle there being no fallback destination keyring for request_key()David Howells2009-04-09
| | | | | | | | | | | | | | | | | | | | | | 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>
* cap_prctl: don't set error to 0 at 'no_change'Serge E. Hallyn2009-04-08
| | | | | | | | | | | | | | | | | 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>
* tomoyo: remove "undelete domain" command.Tetsuo Handa2009-04-07
| | | | | | | | | | 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>
* CacheFiles: Export things for CacheFilesDavid Howells2009-04-03
| | | | | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-04-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * '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 585d3bc06f4ca57f975a5a1f698f65a45ea66225 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()
| * Get rid of indirect include of fs_struct.hAl Viro2009-03-31
| | | | | | | | | | | | | | | | 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>
* | devcgroup: avoid using cgroup_lockLi Zefan2009-04-02
|/ | | | | | | | | | | | | 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>
* smack: Add a new '-CIPSO' option to the network address label configurationEtienne Basset2009-03-28
| | | | | | | | | | | | | 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>
* netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connectionsPaul Moore2009-03-28
| | | | | | | | | | | | | | | 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>
* lsm: Remove the socket_post_accept() hookPaul Moore2009-03-28
| | | | | | | | | | 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>
* selinux: Remove the "compat_net" compatibility codePaul Moore2009-03-28
| | | | | | | | | | 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>
* netlabel: Label incoming TCP connections correctly in SELinuxPaul Moore2009-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* TOMOYO: Fix a typo.Tetsuo Handa2009-03-27
| | | | | | | | | | Fix a typo. Reported-by: Pavel Machek <pavel@ucw.cz> 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>
* smack: convert smack to standard linux listsEtienne Basset2009-03-25
| | | | | | | | | | | 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>
* Merge branch 'master' into nextJames Morris2009-03-23
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| * smack: fixes for unlabeled host supportetienne2009-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * selinux: Fix a panic in selinux_netlbl_inode_permission()Paul Moore2009-03-01
| | | | | | | | | | | | | | | | | | | | | | 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>
| * selinux: Fix the NetLabel glue code for setsockopt()Paul Moore2009-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: inode_doinit_with_dentry drop no dentry printkEric Paris2009-03-09
| | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: new permission between tty audit and audit socketEric Paris2009-03-05
| | | | | | | | | | | | | | | | | | 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>
* | SELinux: open perm for sock filesEric Paris2009-03-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | smack: fixes for unlabeled host supportetienne2009-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | keys: make procfiles per-user-namespaceSerge E. Hallyn2009-02-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | keys: skip keys from another user namespaceSerge E. Hallyn2009-02-26
| | | | | | | | | | | | | | | | | | | | | | 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>
* | keys: consider user namespace in key_permissionSerge E. Hallyn2009-02-26
| | | | | | | | | | | | | | | | | | 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>
* | keys: distinguish per-uid keys in different namespacesSerge E. Hallyn2009-02-26
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | integrity: ima iint radix_tree_lookup locking fixMimi Zohar2009-02-22
| | | | | | | | | | | | | | | | | | | | 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: Do not call tomoyo_realpath_init unless registered.Tetsuo Handa2009-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | integrity: ima scatterlist bug fixMimi Zohar2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on Alexander Beregalov's post http://lkml.org/lkml/2009/2/19/198 - replaced sg_set_buf() with sg_init_one() kernel BUG at include/linux/scatterlist.h:65! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: CPU 2 Modules linked in: Pid: 1, comm: swapper Not tainted 2.6.29-rc5-next-20090219 #5 PowerEdge 1950 RIP: 0010:[<ffffffff8045ec70>] [<ffffffff8045ec70>] ima_calc_hash+0xc0/0x160 RSP: 0018:ffff88007f46bc40 EFLAGS: 00010286 RAX: ffffe200032c45e8 RBX: 00000000fffffff4 RCX: 0000000087654321 RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff88007cf71048 RBP: ffff88007f46bcd0 R08: 0000000000000000 R09: 0000000000000163 R10: ffff88007f4707a8 R11: 0000000000000000 R12: ffff88007cf71048 R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000009d98 FS: 0000000000000000(0000) GS:ffff8800051ac000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000000201000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Tested-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: James Morris <jmorris@namei.org>
* | smack: fix lots of kernel-doc notationRandy Dunlap2009-02-18
| | | | | | | | | | | | | | | | 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>
* | TOMOYO: Don't create securityfs entries unless registered.Tetsuo Handa2009-02-15
| | | | | | | | | | | | | | | | | | | | TOMOYO should not create /sys/kernel/security/tomoyo/ interface unless TOMOYO is 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>
* | TOMOYO: Fix exception policy read failure.Tetsuo Handa2009-02-13
| | | | | | | | | | | | | | | | | | | | Due to wrong initialization, "cat /sys/kernel/security/tomoyo/exception_policy" returned nothing. 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>
* | SELinux: convert the avc cache hash list to an hlistEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: code readability with avc_cacheEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | 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>
* | SELinux: remove unused av.decided fieldEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: more careful use of avd in avc_has_perm_noauditEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: remove the unused ae.usedEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: check seqno when updating an avc_nodeEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: NULL terminate al contexts from diskEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: better printk when file with invalid label foundEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | SELinux: call capabilities code directoryEric Paris2009-02-13
| | | | | | | | | | | | | | | | | | | | | | 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: fix build errorRandy Dunlap2009-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | tomoyo: fix sparse warningTetsuo Handa2009-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix sparse warning. $ make C=2 SUBDIRS=security/tomoyo CF="-D__cold__=" CHECK security/tomoyo/common.c CHECK security/tomoyo/realpath.c CHECK security/tomoyo/tomoyo.c security/tomoyo/tomoyo.c:110:8: warning: symbol 'buf' shadows an earlier one security/tomoyo/tomoyo.c:100:7: originally declared here 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>
* | security: change link order of LSMs so security=tomoyo worksJames Morris2009-02-12
| | | | | | | | | | | | | | | | | | | | 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>
* | Kconfig and MakefileKentaro Takeda2009-02-11
| | | | | | | | | | | | | | | | 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>
* | LSM adapter functions.Kentaro Takeda2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Domain transition handler.Kentaro Takeda2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | File operation restriction part.Kentaro Takeda2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Common functions for TOMOYO Linux.Kentaro Takeda2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Memory and pathname management functions.Kentaro Takeda2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
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