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* CAPABILITIES: remove undefined caps from all processesEric Paris2014-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is effectively a revert of 7b9a7ec565505699f503b4fcf61500dceb36e744 plus fixing it a different way... We found, when trying to run an application from an application which had dropped privs that the kernel does security checks on undefined capability bits. This was ESPECIALLY difficult to debug as those undefined bits are hidden from /proc/$PID/status. Consider a root application which drops all capabilities from ALL 4 capability sets. We assume, since the application is going to set eff/perm/inh from an array that it will clear not only the defined caps less than CAP_LAST_CAP, but also the higher 28ish bits which are undefined future capabilities. The BSET gets cleared differently. Instead it is cleared one bit at a time. The problem here is that in security/commoncap.c::cap_task_prctl() we actually check the validity of a capability being read. So any task which attempts to 'read all things set in bset' followed by 'unset all things set in bset' will not even attempt to unset the undefined bits higher than CAP_LAST_CAP. So the 'parent' will look something like: CapInh: 0000000000000000 CapPrm: 0000000000000000 CapEff: 0000000000000000 CapBnd: ffffffc000000000 All of this 'should' be fine. Given that these are undefined bits that aren't supposed to have anything to do with permissions. But they do... So lets now consider a task which cleared the eff/perm/inh completely and cleared all of the valid caps in the bset (but not the invalid caps it couldn't read out of the kernel). We know that this is exactly what the libcap-ng library does and what the go capabilities library does. They both leave you in that above situation if you try to clear all of you capapabilities from all 4 sets. If that root task calls execve() the child task will pick up all caps not blocked by the bset. The bset however does not block bits higher than CAP_LAST_CAP. So now the child task has bits in eff which are not in the parent. These are 'meaningless' undefined bits, but still bits which the parent doesn't have. The problem is now in cred_cap_issubset() (or any operation which does a subset test) as the child, while a subset for valid cap bits, is not a subset for invalid cap bits! So now we set durring commit creds that the child is not dumpable. Given it is 'more priv' than its parent. It also means the parent cannot ptrace the child and other stupidity. The solution here: 1) stop hiding capability bits in status This makes debugging easier! 2) stop giving any task undefined capability bits. it's simple, it you don't put those invalid bits in CAP_FULL_SET you won't get them in init and you won't get them in any other task either. This fixes the cap_issubset() tests and resulting fallout (which made the init task in a docker container untraceable among other things) 3) mask out undefined bits when sys_capset() is called as it might use ~0, ~0 to denote 'all capabilities' for backward/forward compatibility. This lets 'capsh --caps="all=eip" -- -c /bin/bash' run. 4) mask out undefined bit when we read a file capability off of disk as again likely all bits are set in the xattr for forward/backward compatibility. This lets 'setcap all+pe /bin/bash; /bin/bash' run Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Andrew G. Morgan <morgan@kernel.org> Cc: Serge E. Hallyn <serge.hallyn@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Dan Walsh <dwalsh@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
* Merge tag 'keys-next-20140722' of ↵James Morris2014-07-24
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
| * Merge branch 'keys-fixes' into keys-nextDavid Howells2014-07-22
| |\ | | | | | | | | | Signed-off-by: David Howells <dhowells@redhat.com>
| | * KEYS: Allow special keys (eg. DNS results) to be invalidated by CAP_SYS_ADMINDavid Howells2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Special kernel keys, such as those used to hold DNS results for AFS, CIFS and NFS and those used to hold idmapper results for NFS, used to be 'invalidateable' with key_revoke(). However, since the default permissions for keys were reduced: Commit: 96b5c8fea6c0861621051290d705ec2e971963f1 KEYS: Reduce initial permissions on keys it has become impossible to do this. Add a key flag (KEY_FLAG_ROOT_CAN_INVAL) that will permit a key to be invalidated by root. This should not be used for system keyrings as the garbage collector will try and remove any invalidate key. For system keyrings, KEY_FLAG_ROOT_CAN_CLEAR can be used instead. After this, from userspace, keyctl_invalidate() and "keyctl invalidate" can be used by any possessor of CAP_SYS_ADMIN (typically root) to invalidate DNS and idmapper keys. Invalidated keys are immediately garbage collected and will be immediately rerequested if needed again. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Steve Dickson <steved@redhat.com>
| * | Merge remote-tracking branch 'integrity/next-with-keys' into keys-nextDavid Howells2014-07-22
| |\ \ | | | | | | | | | | | | Signed-off-by: David Howells <dhowells@redhat.com>
| | * | ima: define '.ima' as a builtin 'trusted' keyringMimi Zohar2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Require all keys added to the IMA keyring be signed by an existing trusted key on the system trusted keyring. Changelog v6: - remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry - update Kconfig dependency and help - select KEYS_DEBUG_PROC_KEYS - Dmitry Changelog v5: - Move integrity_init_keyring() to init_ima() - Dmitry - reset keyring[id] on failure - Dmitry Changelog v1: - don't link IMA trusted keyring to user keyring Changelog: - define stub integrity_init_keyring() function (reported-by Fengguang Wu) - differentiate between regular and trusted keyring names. - replace printk with pr_info (D. Kasatkin) - only make the IMA keyring a trusted keyring (reported-by D. Kastatkin) - define stub integrity_init_keyring() definition based on CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS. (reported-by Jim Davis) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Acked-by: David Howells <dhowells@redhat.com>
| | * | KEYS: special dot prefixed keyring name bug fixMimi Zohar2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dot prefixed keyring names are supposed to be reserved for the kernel, but add_key() calls key_get_type_from_user(), which incorrectly verifies the 'type' field, not the 'description' field. This patch verifies the 'description' field isn't dot prefixed, when creating a new keyring, and removes the dot prefix test in key_get_type_from_user(). Changelog v6: - whitespace and other cleanup Changelog v5: - Only prevent userspace from creating a dot prefixed keyring, not regular keys - Dmitry Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com>
| * | | KEYS: request_key_auth: Provide key preparsingDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide key preparsing for the request_key_auth key type so that we can make preparsing mandatory. This does nothing as this type can only be set up internally to the kernel. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com>
| * | | KEYS: keyring: Provide key preparsingDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide key preparsing in the keyring so that we can make preparsing mandatory. For keyrings, however, only an empty payload is permitted. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com>
| * | | KEYS: big_key: Use key preparsingDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make use of key preparsing in the big key type so that quota size determination can take place prior to keyring locking when a key is being added. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com>
| * | | KEYS: user: Use key preparsingDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make use of key preparsing in user-defined and logon keys so that quota size determination can take place prior to keyring locking when a key is being added. Also the idmapper key types need to change to match as they use the user-defined key type routines. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com>
| * | | KEYS: Call ->free_preparse() even after ->preparse() returns an errorDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call the ->free_preparse() key type op even after ->preparse() returns an error as it does cleaning up type stuff. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Sage Weil <sage@redhat.com>
| * | | KEYS: Allow expiry time to be set when preparsing a keyDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow a key type's preparsing routine to set the expiry time for a key. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Sage Weil <sage@redhat.com>
| * | | KEYS: struct key_preparsed_payload should have two payload pointersDavid Howells2014-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct key_preparsed_payload should have two payload pointers to correspond with those in struct key. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Sage Weil <sage@redhat.com>
| * | | KEYS: Provide a generic instantiation functionDavid Howells2014-07-18
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a generic instantiation function for key types that use the preparse hook. This makes it easier to prereserve key quota before keyrings get locked to retain the new key. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Sage Weil <sage@redhat.com>
* | | commoncap: don't alloc the credential unless needed in cap_task_prctlTetsuo Handa2014-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In function cap_task_prctl(), we would allocate a credential unconditionally and then check if we support the requested function. If not we would release this credential with abort_creds() by using RCU method. But on some archs such as powerpc, the sys_prctl is heavily used to get/set the floating point exception mode. So the unnecessary allocating/releasing of credential not only introduce runtime overhead but also do cause OOM due to the RCU implementation. This patch removes abort_creds() from cap_task_prctl() by calling prepare_creds() only when we need to modify it. Reported-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Paul Moore <paul@paul-moore.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
* | | Merge tag 'seccomp-3.17' of ↵James Morris2014-07-19
|\ \ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into next
| * | | sched: move no_new_privs into new atomic flagsKees Cook2014-07-18
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since seccomp transitions between threads requires updates to the no_new_privs flag to be atomic, the flag must be part of an atomic flag set. This moves the nnp flag into a separate task field, and introduces accessors. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net>
* | | Merge branch 'next' of git://git.infradead.org/users/pcmoore/selinux into nextJames Morris2014-07-19
|\ \ \ | |/ / |/| |
| * | selinux: reduce the number of calls to synchronize_net() when flushing cachesPaul Moore2014-06-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When flushing the AVC, such as during a policy load, the various network caches are also flushed, with each making a call to synchronize_net() which has shown to be expensive in some cases. This patch consolidates the network cache flushes into a single AVC callback which only calls synchronize_net() once for each AVC cache flush. Reported-by: Jaejyn Shin <flagon22bass@gmail.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | selinux: no recursive read_lock of policy_rwlock in security_genfs_sid()Waiman Long2014-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the introduction of fair queued rwlock, recursive read_lock() may hang the offending process if there is a write_lock() somewhere in between. With recursive read_lock checking enabled, the following error was reported: ============================================= [ INFO: possible recursive locking detected ] 3.16.0-rc1 #2 Tainted: G E --------------------------------------------- load_policy/708 is trying to acquire lock: (policy_rwlock){.+.+..}, at: [<ffffffff8125b32a>] security_genfs_sid+0x3a/0x170 but task is already holding lock: (policy_rwlock){.+.+..}, at: [<ffffffff8125b48c>] security_fs_use+0x2c/0x110 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(policy_rwlock); lock(policy_rwlock); This patch fixes the occurrence of recursive read_lock() of policy_rwlock by adding a helper function __security_genfs_sid() which requires caller to take the lock before calling it. The security_fs_use() was then modified to call the new helper function. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | selinux: fix a possible memory leak in cond_read_node()Namhyung Kim2014-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | The cond_read_node() should free the given node on error path as it's not linked to p->cond_list yet. This is done via cond_node_destroy() but it's not called when next_entry() fails before the expr loop. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | selinux: simple cleanup for cond_read_node()Namhyung Kim2014-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | The node->cur_state and len can be read in a single call of next_entry(). And setting len before reading is a dead write so can be eliminated. Signed-off-by: Namhyung Kim <namhyung@kernel.org> (Minor tweak to the length parameter in the call to next_entry()) Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | security: Used macros from compiler.h instead of __attribute__((...))Gideon Israel Dsouza2014-06-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To increase compiler portability there is <linux/compiler.h> which provides convenience macros for various gcc constructs. Eg: __packed for __attribute__((packed)). This patch is part of a large task I've taken to clean the gcc specific attributes and use the the macros instead. Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | selinux: introduce str_read() helperNamhyung Kim2014-06-18
| | | | | | | | | | | | | | | | | | | | | | | | There're some code duplication for reading a string value during policydb_read(). Add str_read() helper to fix it. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | SELinux: use ARRAY_SIZEHimangi Saraogi2014-06-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARRAY_SIZE is more concise to use when the size of an array is divided by the size of its type or the size of its first element. The Coccinelle semantic patch that makes this change is as follows: // <smpl> @@ type T; T[] E; @@ - (sizeof(E)/sizeof(E[...])) + ARRAY_SIZE(E) // </smpl> Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
* | | ima: provide double buffering for hash calculationDmitry Kasatkin2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The asynchronous hash API allows initiating a hash calculation and then performing other tasks, while waiting for the hash calculation to complete. This patch introduces usage of double buffering for simultaneous hashing and reading of the next chunk of data from storage. Changes in v3: - better comments Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | ima: introduce multi-page collect buffersDmitry Kasatkin2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use of multiple-page collect buffers reduces: 1) the number of block IO requests 2) the number of asynchronous hash update requests Second is important for HW accelerated hashing, because significant amount of time is spent for preparation of hash update operation, which includes configuring acceleration HW, DMA engine, etc... Thus, HW accelerators are more efficient when working on large chunks of data. This patch introduces usage of multi-page collect buffers. Buffer size can be specified using 'ahash_bufsize' module parameter. Default buffer size is 4096 bytes. Changes in v3: - kernel parameter replaced with module parameter Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | ima: use ahash API for file hash calculationDmitry Kasatkin2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Async hash API allows the use of HW acceleration for hash calculation. It may give significant performance gain and/or reduce power consumption, which might be very beneficial for battery powered devices. This patch introduces hash calculation using ahash API. ahash performance depends on the data size and the particular HW. Depending on the specific system, shash performance may be better. This patch defines 'ahash_minsize' module parameter, which is used to define the minimal file size to use with ahash. If this minimum file size is not set or the file is smaller than defined by the parameter, shash will be used. Changes in v3: - kernel parameter replaced with module parameter - pr_crit replaced with pr_crit_ratelimited - more comment changes - Mimi Changes in v2: - ima_ahash_size became as ima_ahash - ahash pre-allocation moved out from __init code to be able to use ahash crypto modules. Ahash allocated once on the first use. - hash calculation falls back to shash if ahash allocation/calculation fails - complex initialization separated from variable declaration - improved comments Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | audit: fix dangling keywords in integrity ima message outputRichard Guy Briggs2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | Replace spaces in op keyword labels in log output since userspace audit tools can't parse orphaned keywords. Reported-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | ima: delay template descriptor lookup until useDmitry Kasatkin2014-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | process_measurement() always calls ima_template_desc_current(), including when an IMA policy has not been defined. This patch delays template descriptor lookup until action is determined. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | ima: remove unnecessary i_mutex locking from ima_rdwr_violation_check()Dmitry Kasatkin2014-07-17
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | Before 2.6.39 inode->i_readcount was maintained by IMA. It was not atomic and protected using spinlock. For 2.6.39, i_readcount was converted to atomic and maintaining was moved VFS layer. Spinlock for some unclear reason was replaced by i_mutex. After analyzing the code, we came to conclusion that i_mutex locking is unnecessary, especially when an IMA policy has not been defined. This patch removes i_mutex locking from ima_rdwr_violation_check(). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | Merge branch 'stable-3.16' of git://git.infradead.org/users/pcmoore/selinux ↵James Morris2014-07-16
|\ \ | | | | | | | | | into next
| * | selinux: fix the default socket labeling in sock_graft()Paul Moore2014-07-10
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sock_graft() hook has special handling for AF_INET, AF_INET, and AF_UNIX sockets as those address families have special hooks which label the sock before it is attached its associated socket. Unfortunately, the sock_graft() hook was missing a default approach to labeling sockets which meant that any other address family which made use of connections or the accept() syscall would find the returned socket to be in an "unlabeled" state. This was recently demonstrated by the kcrypto/AF_ALG subsystem and the newly released cryptsetup package (cryptsetup v1.6.5 and later). This patch preserves the special handling in selinux_sock_graft(), but adds a default behavior - setting the sock's label equal to the associated socket - which resolves the problem with AF_ALG and presumably any other address family which makes use of accept(). Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com> Tested-by: Milan Broz <gmazyland@gmail.com>
| * Merge tag 'v3.15' into nextPaul Moore2014-06-17
| |\ | | | | | | | | | Linux 3.15
| * | selinux: conditionally reschedule in hashtab_insert while loading selinux policyDave Jones2014-05-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | After silencing the sleeping warning in mls_convert_context() I started seeing similar traces from hashtab_insert. Do a cond_resched there too. Signed-off-by: Dave Jones <davej@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | selinux: conditionally reschedule in mls_convert_context while loading ↵Dave Jones2014-05-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | selinux policy On a slow machine (with debugging enabled), upgrading selinux policy may take a considerable amount of time. Long enough that the softlockup detector gets triggered. The backtrace looks like this.. > BUG: soft lockup - CPU#2 stuck for 23s! [load_policy:19045] > Call Trace: > [<ffffffff81221ddf>] symcmp+0xf/0x20 > [<ffffffff81221c27>] hashtab_search+0x47/0x80 > [<ffffffff8122e96c>] mls_convert_context+0xdc/0x1c0 > [<ffffffff812294e8>] convert_context+0x378/0x460 > [<ffffffff81229170>] ? security_context_to_sid_core+0x240/0x240 > [<ffffffff812221b5>] sidtab_map+0x45/0x80 > [<ffffffff8122bb9f>] security_load_policy+0x3ff/0x580 > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > [<ffffffff810786dd>] ? sched_clock_local+0x1d/0x80 > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > [<ffffffff8103096a>] ? __change_page_attr_set_clr+0x82a/0xa50 > [<ffffffff810786dd>] ? sched_clock_local+0x1d/0x80 > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > [<ffffffff8103096a>] ? __change_page_attr_set_clr+0x82a/0xa50 > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > [<ffffffff81534ddc>] ? retint_restore_args+0xe/0xe > [<ffffffff8109c82d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 > [<ffffffff81279a2e>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff810d28a8>] ? rcu_irq_exit+0x68/0xb0 > [<ffffffff81534ddc>] ? retint_restore_args+0xe/0xe > [<ffffffff8121e947>] sel_write_load+0xa7/0x770 > [<ffffffff81139633>] ? vfs_write+0x1c3/0x200 > [<ffffffff81210e8e>] ? security_file_permission+0x1e/0xa0 > [<ffffffff8113952b>] vfs_write+0xbb/0x200 > [<ffffffff811581c7>] ? fget_light+0x397/0x4b0 > [<ffffffff81139c27>] SyS_write+0x47/0xa0 > [<ffffffff8153bde4>] tracesys+0xdd/0xe2 Stephen Smalley suggested: > Maybe put a cond_resched() within the ebitmap_for_each_positive_bit() > loop in mls_convert_context()? That seems to do the trick. Tested by downgrading and re-upgrading selinux-policy-targeted. Signed-off-by: Dave Jones <davej@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | selinux: reject setexeccon() on MNT_NOSUID applications with -EACCESPaul Moore2014-05-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We presently prevent processes from using setexecon() to set the security label of exec()'d processes when NO_NEW_PRIVS is enabled by returning an error; however, we silently ignore setexeccon() when exec()'ing from a nosuid mounted filesystem. This patch makes things a bit more consistent by returning an error in the setexeccon()/nosuid case. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
| * | selinux: Report permissive mode in avc: denied messages.Stephen Smalley2014-05-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We cannot presently tell from an avc: denied message whether access was in fact denied or was allowed due to global or per-domain permissive mode. Add a permissive= field to the avc message to reflect this information. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
| * | Merge tag 'v3.14' into nextPaul Moore2014-03-31
| |\ \ | | | | | | | | | | | | Linux 3.14
| * | | selinux: correctly label /proc inodes in use before the policy is loadedPaul Moore2014-03-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is based on an earlier patch by Eric Paris, he describes the problem below: "If an inode is accessed before policy load it will get placed on a list of inodes to be initialized after policy load. After policy load we call inode_doinit() which calls inode_doinit_with_dentry() on all inodes accessed before policy load. In the case of inodes in procfs that means we'll end up at the bottom where it does: /* Default to the fs superblock SID. */ isec->sid = sbsec->sid; if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { if (opt_dentry) { isec->sclass = inode_mode_to_security_class(...) rc = selinux_proc_get_sid(opt_dentry, isec->sclass, &sid); if (rc) goto out_unlock; isec->sid = sid; } } Since opt_dentry is null, we'll never call selinux_proc_get_sid() and will leave the inode labeled with the label on the superblock. I believe a fix would be to mimic the behavior of xattrs. Look for an alias of the inode. If it can't be found, just leave the inode uninitialized (and pick it up later) if it can be found, we should be able to call selinux_proc_get_sid() ..." On a system exhibiting this problem, you will notice a lot of files in /proc with the generic "proc_t" type (at least the ones that were accessed early in the boot), for example: # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }' system_u:object_r:proc_t:s0 /proc/sys/kernel/shmmax However, with this patch in place we see the expected result: # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }' system_u:object_r:sysctl_kernel_t:s0 /proc/sys/kernel/shmmax Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@redhat.com>
| * | | selinux: put the mmap() DAC controls before the MAC controlsPaul Moore2014-02-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It turns out that doing the SELinux MAC checks for mmap() before the DAC checks was causing users and the SELinux policy folks headaches as users were seeing a lot of SELinux AVC denials for the memprotect:mmap_zero permission that would have also been denied by the normal DAC capability checks (CAP_SYS_RAWIO). Example: # cat mmap_test.c #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <sys/mman.h> int main(int argc, char *argv[]) { int rc; void *mem; mem = mmap(0x0, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); if (mem == MAP_FAILED) return errno; printf("mem = %p\n", mem); munmap(mem, 4096); return 0; } # gcc -g -O0 -o mmap_test mmap_test.c # ./mmap_test mem = (nil) # ausearch -m AVC | grep mmap_zero type=AVC msg=audit(...): avc: denied { mmap_zero } for pid=1025 comm="mmap_test" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=memprotect This patch corrects things so that when the above example is run by a user without CAP_SYS_RAWIO the SELinux AVC is no longer generated as the DAC capability check fails before the SELinux permission check. Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
| * | | Merge tag 'v3.13' into nextPaul Moore2014-01-23
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 3.13 Minor fixup needed in selinux_inet_conn_request() Conflicts: security/selinux/hooks.c
* | \ \ \ Merge branch 'serge-next-2' of ↵Linus Torvalds2014-06-13
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security Pull more security layer updates from Serge Hallyn: "A few more commits had previously failed to make it through security-next into linux-next but this week made it into linux-next. At least commit "ima: introduce ima_kernel_read()" was deemed critical by Mimi to make this merge window. This is a temporary tree just for this request. Mimi has pointed me to some previous threads about keeping maintainer trees at the previous release, which I'll certainly do for anything long-term, after talking with James" * 'serge-next-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security: ima: introduce ima_kernel_read() evm: prohibit userspace writing 'security.evm' HMAC value ima: check inode integrity cache in violation check ima: prevent unnecessary policy checking evm: provide option to protect additional SMACK xattrs evm: replace HMAC version with attribute mask ima: prevent new digsig xattr from being replaced
| * | | | | ima: introduce ima_kernel_read()Dmitry Kasatkin2014-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8aac62706 "move exit_task_namespaces() outside of exit_notify" introduced the kernel opps since the kernel v3.10, which happens when Apparmor and IMA-appraisal are enabled at the same time. ---------------------------------------------------------------------- [ 106.750167] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 106.750221] IP: [<ffffffff811ec7da>] our_mnt+0x1a/0x30 [ 106.750241] PGD 0 [ 106.750254] Oops: 0000 [#1] SMP [ 106.750272] Modules linked in: cuse parport_pc ppdev bnep rfcomm bluetooth rpcsec_gss_krb5 nfsd auth_rpcgss nfs_acl nfs lockd sunrpc fscache dm_crypt intel_rapl x86_pkg_temp_thermal intel_powerclamp kvm_intel snd_hda_codec_hdmi kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd snd_hda_codec_realtek dcdbas snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_seq_midi snd_seq_midi_event snd_rawmidi psmouse snd_seq microcode serio_raw snd_timer snd_seq_device snd soundcore video lpc_ich coretemp mac_hid lp parport mei_me mei nbd hid_generic e1000e usbhid ahci ptp hid libahci pps_core [ 106.750658] CPU: 6 PID: 1394 Comm: mysqld Not tainted 3.13.0-rc7-kds+ #15 [ 106.750673] Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A08 09/19/2012 [ 106.750689] task: ffff8800de804920 ti: ffff880400fca000 task.ti: ffff880400fca000 [ 106.750704] RIP: 0010:[<ffffffff811ec7da>] [<ffffffff811ec7da>] our_mnt+0x1a/0x30 [ 106.750725] RSP: 0018:ffff880400fcba60 EFLAGS: 00010286 [ 106.750738] RAX: 0000000000000000 RBX: 0000000000000100 RCX: ffff8800d51523e7 [ 106.750764] RDX: ffffffffffffffea RSI: ffff880400fcba34 RDI: ffff880402d20020 [ 106.750791] RBP: ffff880400fcbae0 R08: 0000000000000000 R09: 0000000000000001 [ 106.750817] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8800d5152300 [ 106.750844] R13: ffff8803eb8df510 R14: ffff880400fcbb28 R15: ffff8800d51523e7 [ 106.750871] FS: 0000000000000000(0000) GS:ffff88040d200000(0000) knlGS:0000000000000000 [ 106.750910] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 106.750935] CR2: 0000000000000018 CR3: 0000000001c0e000 CR4: 00000000001407e0 [ 106.750962] Stack: [ 106.750981] ffffffff813434eb ffff880400fcbb20 ffff880400fcbb18 0000000000000000 [ 106.751037] ffff8800de804920 ffffffff8101b9b9 0001800000000000 0000000000000100 [ 106.751093] 0000010000000000 0000000000000002 000000000000000e ffff8803eb8df500 [ 106.751149] Call Trace: [ 106.751172] [<ffffffff813434eb>] ? aa_path_name+0x2ab/0x430 [ 106.751199] [<ffffffff8101b9b9>] ? sched_clock+0x9/0x10 [ 106.751225] [<ffffffff8134a68d>] aa_path_perm+0x7d/0x170 [ 106.751250] [<ffffffff8101b945>] ? native_sched_clock+0x15/0x80 [ 106.751276] [<ffffffff8134aa73>] aa_file_perm+0x33/0x40 [ 106.751301] [<ffffffff81348c5e>] common_file_perm+0x8e/0xb0 [ 106.751327] [<ffffffff81348d78>] apparmor_file_permission+0x18/0x20 [ 106.751355] [<ffffffff8130c853>] security_file_permission+0x23/0xa0 [ 106.751382] [<ffffffff811c77a2>] rw_verify_area+0x52/0xe0 [ 106.751407] [<ffffffff811c789d>] vfs_read+0x6d/0x170 [ 106.751432] [<ffffffff811cda31>] kernel_read+0x41/0x60 [ 106.751457] [<ffffffff8134fd45>] ima_calc_file_hash+0x225/0x280 [ 106.751483] [<ffffffff8134fb52>] ? ima_calc_file_hash+0x32/0x280 [ 106.751509] [<ffffffff8135022d>] ima_collect_measurement+0x9d/0x160 [ 106.751536] [<ffffffff810b552d>] ? trace_hardirqs_on+0xd/0x10 [ 106.751562] [<ffffffff8134f07c>] ? ima_file_free+0x6c/0xd0 [ 106.751587] [<ffffffff81352824>] ima_update_xattr+0x34/0x60 [ 106.751612] [<ffffffff8134f0d0>] ima_file_free+0xc0/0xd0 [ 106.751637] [<ffffffff811c9635>] __fput+0xd5/0x300 [ 106.751662] [<ffffffff811c98ae>] ____fput+0xe/0x10 [ 106.751687] [<ffffffff81086774>] task_work_run+0xc4/0xe0 [ 106.751712] [<ffffffff81066fad>] do_exit+0x2bd/0xa90 [ 106.751738] [<ffffffff8173c958>] ? retint_swapgs+0x13/0x1b [ 106.751763] [<ffffffff8106780c>] do_group_exit+0x4c/0xc0 [ 106.751788] [<ffffffff81067894>] SyS_exit_group+0x14/0x20 [ 106.751814] [<ffffffff8174522d>] system_call_fastpath+0x1a/0x1f [ 106.751839] Code: c3 0f 1f 44 00 00 55 48 89 e5 e8 22 fe ff ff 5d c3 0f 1f 44 00 00 55 65 48 8b 04 25 c0 c9 00 00 48 8b 80 28 06 00 00 48 89 e5 5d <48> 8b 40 18 48 39 87 c0 00 00 00 0f 94 c0 c3 0f 1f 80 00 00 00 [ 106.752185] RIP [<ffffffff811ec7da>] our_mnt+0x1a/0x30 [ 106.752214] RSP <ffff880400fcba60> [ 106.752236] CR2: 0000000000000018 [ 106.752258] ---[ end trace 3c520748b4732721 ]--- ---------------------------------------------------------------------- The reason for the oops is that IMA-appraisal uses "kernel_read()" when file is closed. kernel_read() honors LSM security hook which calls Apparmor handler, which uses current->nsproxy->mnt_ns. The 'guilty' commit changed the order of cleanup code so that nsproxy->mnt_ns was not already available for Apparmor. Discussion about the issue with Al Viro and Eric W. Biederman suggested that kernel_read() is too high-level for IMA. Another issue, except security checking, that was identified is mandatory locking. kernel_read honors it as well and it might prevent IMA from calculating necessary hash. It was suggested to use simplified version of the function without security and locking checks. This patch introduces special version ima_kernel_read(), which skips security and mandatory locking checking. It prevents the kernel oops to happen. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org>
| * | | | | evm: prohibit userspace writing 'security.evm' HMAC valueMimi Zohar2014-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calculating the 'security.evm' HMAC value requires access to the EVM encrypted key. Only the kernel should have access to it. This patch prevents userspace tools(eg. setfattr, cp --preserve=xattr) from setting/modifying the 'security.evm' HMAC value directly. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org>
| * | | | | ima: check inode integrity cache in violation checkDmitry Kasatkin2014-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When IMA did not support ima-appraisal, existance of the S_IMA flag clearly indicated that the file was measured. With IMA appraisal S_IMA flag indicates that file was measured and/or appraised. Because of this, when measurement is not enabled by the policy, violations are still reported. To differentiate between measurement and appraisal policies this patch checks the inode integrity cache flags. The IMA_MEASURED flag indicates whether the file was actually measured, while the IMA_MEASURE flag indicates whether the file should be measured. Unfortunately, the IMA_MEASURED flag is reset to indicate the file needs to be re-measured. Thus, this patch checks the IMA_MEASURE flag. This patch limits the false positive violation reports, but does not fix it entirely. The IMA_MEASURE/IMA_MEASURED flags are indications that, at some point in time, the file opened for read was in policy, but might not be in policy now (eg. different uid). Other changes would be needed to further limit false positive violation reports. Changelog: - expanded patch description based on conversation with Roberto (Mimi) Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
| * | | | | ima: prevent unnecessary policy checkingDmitry Kasatkin2014-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ima_rdwr_violation_check is called for every file openning. The function checks the policy even when violation condition is not met. It causes unnecessary policy checking. This patch does policy checking only if violation condition is met. Changelog: - check writecount is greater than zero (Mimi) Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
| * | | | | evm: provide option to protect additional SMACK xattrsDmitry Kasatkin2014-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Newer versions of SMACK introduced following security xattrs: SMACK64EXEC, SMACK64TRANSMUTE and SMACK64MMAP. To protect these xattrs, this patch includes them in the HMAC calculation. However, for backwards compatibility with existing labeled filesystems, including these xattrs needs to be configurable. Changelog: - Add SMACK dependency on new option (Mimi) Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
| * | | | | evm: replace HMAC version with attribute maskDmitry Kasatkin2014-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using HMAC version limits the posibility to arbitrarily add new attributes such as SMACK64EXEC to the hmac calculation. This patch replaces hmac version with attribute mask. Desired attributes can be enabled with configuration parameter. It allows to build kernels which works with previously labeled filesystems. Currently supported attribute is 'fsuuid' which is equivalent of the former version 2. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-21 22:06:54 -0500