Commit 18240904 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus3' of... 

Merge branch 'for-linus3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  SELinux: inline selinux_is_enabled in !CONFIG_SECURITY_SELINUX
  KEYS: Fix garbage collector
  KEYS: Unlock tasklist when exiting early from keyctl_session_to_parent
  CRED: Allow put_cred() to cope with a NULL groups list
  SELinux: flush the avc before disabling SELinux
  SELinux: seperate avc_cache flushing
  Creds: creds->security can be NULL is selinux is disabled
parents f86054c2 8a478905

include/linux/cred.h

+8 −5
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/capability.h>

#include <linux/init.h>

#include <linux/key.h>

#include <linux/selinux.h>

#include <asm/atomic.h>



struct user_struct;
@@ -182,11 +183,13 @@ static inline bool creds_are_invalid(const struct cred *cred) 
	if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))

		return true;

#ifdef CONFIG_SECURITY_SELINUX

	if (selinux_is_enabled()) {

		if ((unsigned long) cred->security < PAGE_SIZE)

			return true;

		if ((*(u32 *)cred->security & 0xffffff00) ==

		    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))

			return true;

	}

#endif

	return false;

}

include/linux/selinux.h

+9 −0
Original line number Diff line number Diff line
@@ -61,6 +61,11 @@ void selinux_secmark_refcount_inc(void); 
 *     existing SECMARK targets has been removed/flushed.

 */

void selinux_secmark_refcount_dec(void);



/**

 * selinux_is_enabled - is SELinux enabled?

 */

bool selinux_is_enabled(void);

#else



static inline int selinux_string_to_sid(const char *str, u32 *sid)
@@ -84,6 +89,10 @@ static inline void selinux_secmark_refcount_dec(void) 
	return;

}



static inline bool selinux_is_enabled(void)

{

	return false;

}

#endif	/* CONFIG_SECURITY_SELINUX */



#endif /* _LINUX_SELINUX_H */

kernel/cred.c

+2 −1
Original line number Diff line number Diff line
@@ -147,6 +147,7 @@ static void put_cred_rcu(struct rcu_head *rcu) 
	key_put(cred->thread_keyring);

	key_put(cred->request_key_auth);

	release_tgcred(cred);

	if (cred->group_info)

		put_group_info(cred->group_info);

	free_uid(cred->user);

	kmem_cache_free(cred_jar, cred);

security/keys/gc.c

+51 −27
Original line number Diff line number Diff line
@@ -26,8 +26,10 @@ static void key_garbage_collector(struct work_struct *); 
static DEFINE_TIMER(key_gc_timer, key_gc_timer_func, 0, 0);

static DECLARE_WORK(key_gc_work, key_garbage_collector);

static key_serial_t key_gc_cursor; /* the last key the gc considered */

static bool key_gc_again;

static unsigned long key_gc_executing;

static time_t key_gc_next_run = LONG_MAX;

static time_t key_gc_new_timer;



/*

 * Schedule a garbage collection run
@@ -40,9 +42,7 @@ void key_schedule_gc(time_t gc_at) 


	kenter("%ld", gc_at - now);



	gc_at += key_gc_delay;



	if (now >= gc_at) {

	if (gc_at <= now) {

		schedule_work(&key_gc_work);

	} else if (gc_at < key_gc_next_run) {

		expires = jiffies + (gc_at - now) * HZ;
@@ -112,16 +112,18 @@ static void key_garbage_collector(struct work_struct *work) 
	struct rb_node *rb;

	key_serial_t cursor;

	struct key *key, *xkey;

	time_t new_timer = LONG_MAX, limit;

	time_t new_timer = LONG_MAX, limit, now;



	kenter("");

	now = current_kernel_time().tv_sec;

	kenter("[%x,%ld]", key_gc_cursor, key_gc_new_timer - now);



	if (test_and_set_bit(0, &key_gc_executing)) {

		key_schedule_gc(current_kernel_time().tv_sec);

		key_schedule_gc(current_kernel_time().tv_sec + 1);

		kleave(" [busy; deferring]");

		return;

	}



	limit = current_kernel_time().tv_sec;

	limit = now;

	if (limit > key_gc_delay)

		limit -= key_gc_delay;

	else
@@ -129,12 +131,19 @@ static void key_garbage_collector(struct work_struct *work) 


	spin_lock(&key_serial_lock);



	if (RB_EMPTY_ROOT(&key_serial_tree))

		goto reached_the_end;

	if (unlikely(RB_EMPTY_ROOT(&key_serial_tree))) {

		spin_unlock(&key_serial_lock);

		clear_bit(0, &key_gc_executing);

		return;

	}



	cursor = key_gc_cursor;

	if (cursor < 0)

		cursor = 0;

	if (cursor > 0)

		new_timer = key_gc_new_timer;

	else

		key_gc_again = false;



	/* find the first key above the cursor */

	key = NULL;
@@ -160,35 +169,50 @@ static void key_garbage_collector(struct work_struct *work) 


	/* trawl through the keys looking for keyrings */

	for (;;) {

		if (key->expiry > 0 && key->expiry < new_timer)

		if (key->expiry > now && key->expiry < new_timer) {

			kdebug("will expire %x in %ld",

			       key_serial(key), key->expiry - now);

			new_timer = key->expiry;

		}



		if (key->type == &key_type_keyring &&

		    key_gc_keyring(key, limit)) {

			/* the gc ate our lock */

			schedule_work(&key_gc_work);

			goto no_unlock;

		}

		    key_gc_keyring(key, limit))

			/* the gc had to release our lock so that the keyring

			 * could be modified, so we have to get it again */

			goto gc_released_our_lock;



		rb = rb_next(&key->serial_node);

		if (!rb) {

			key_gc_cursor = 0;

			break;

		}

		if (!rb)

			goto reached_the_end;

		key = rb_entry(rb, struct key, serial_node);

	}



out:

	spin_unlock(&key_serial_lock);

no_unlock:

gc_released_our_lock:

	kdebug("gc_released_our_lock");

	key_gc_new_timer = new_timer;

	key_gc_again = true;

	clear_bit(0, &key_gc_executing);

	if (new_timer < LONG_MAX)

		key_schedule_gc(new_timer);



	kleave("");

	schedule_work(&key_gc_work);

	kleave(" [continue]");

	return;



	/* when we reach the end of the run, we set the timer for the next one */

reached_the_end:

	kdebug("reached_the_end");

	spin_unlock(&key_serial_lock);

	key_gc_new_timer = new_timer;

	key_gc_cursor = 0;

	goto out;

	clear_bit(0, &key_gc_executing);



	if (key_gc_again) {

		/* there may have been a key that expired whilst we were

		 * scanning, so if we discarded any links we should do another

		 * scan */

		new_timer = now + 1;

		key_schedule_gc(new_timer);

	} else if (new_timer < LONG_MAX) {

		new_timer += key_gc_delay;

		key_schedule_gc(new_timer);

	}

	kleave(" [end]");

}

security/keys/key.c

+2 −2
Original line number Diff line number Diff line
@@ -500,7 +500,7 @@ int key_negate_and_link(struct key *key, 
		set_bit(KEY_FLAG_INSTANTIATED, &key->flags);

		now = current_kernel_time();

		key->expiry = now.tv_sec + timeout;

		key_schedule_gc(key->expiry);

		key_schedule_gc(key->expiry + key_gc_delay);



		if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))

			awaken = 1;
@@ -909,7 +909,7 @@ void key_revoke(struct key *key) 
	time = now.tv_sec;

	if (key->revoked_at == 0 || key->revoked_at > time) {

		key->revoked_at = time;

		key_schedule_gc(key->revoked_at);

		key_schedule_gc(key->revoked_at + key_gc_delay);

	}



	up_write(&key->sem);

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