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-rw-r--r--security/keys/gc.c87
-rw-r--r--security/keys/internal.h2
-rw-r--r--security/keys/key.c72
3 files changed, 85 insertions, 76 deletions
diff --git a/security/keys/gc.c b/security/keys/gc.c
index 89df6b5f203..b23db3fbb32 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -10,6 +10,8 @@
*/
#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/security.h>
#include <keys/keyring-type.h>
#include "internal.h"
@@ -19,12 +21,18 @@
unsigned key_gc_delay = 5 * 60;
/*
- * Reaper
+ * Reaper for unused keys.
+ */
+static void key_gc_unused_keys(struct work_struct *work);
+DECLARE_WORK(key_gc_unused_work, key_gc_unused_keys);
+
+/*
+ * Reaper for links from keyrings to dead keys.
*/
static void key_gc_timer_func(unsigned long);
-static void key_garbage_collector(struct work_struct *);
+static void key_gc_dead_links(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 DECLARE_WORK(key_gc_work, key_gc_dead_links);
static key_serial_t key_gc_cursor; /* the last key the gc considered */
static bool key_gc_again;
static unsigned long key_gc_executing;
@@ -108,10 +116,12 @@ do_gc:
}
/*
- * Garbage collector for keys. This involves scanning the keyrings for dead,
- * expired and revoked keys that have overstayed their welcome
+ * Garbage collector for links to dead keys.
+ *
+ * This involves scanning the keyrings for dead, expired and revoked keys that
+ * have overstayed their welcome
*/
-static void key_garbage_collector(struct work_struct *work)
+static void key_gc_dead_links(struct work_struct *work)
{
struct rb_node *rb;
key_serial_t cursor;
@@ -220,3 +230,68 @@ reached_the_end:
}
kleave(" [end]");
}
+
+/*
+ * Garbage collector for unused keys.
+ *
+ * This is done in process context so that we don't have to disable interrupts
+ * all over the place. key_put() schedules this rather than trying to do the
+ * cleanup itself, which means key_put() doesn't have to sleep.
+ */
+static void key_gc_unused_keys(struct work_struct *work)
+{
+ struct rb_node *_n;
+ struct key *key;
+
+go_again:
+ /* look for a dead key in the tree */
+ spin_lock(&key_serial_lock);
+
+ for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
+ key = rb_entry(_n, struct key, serial_node);
+
+ if (atomic_read(&key->usage) == 0)
+ goto found_dead_key;
+ }
+
+ spin_unlock(&key_serial_lock);
+ return;
+
+found_dead_key:
+ /* we found a dead key - once we've removed it from the tree, we can
+ * drop the lock */
+ rb_erase(&key->serial_node, &key_serial_tree);
+ spin_unlock(&key_serial_lock);
+
+ key_check(key);
+
+ security_key_free(key);
+
+ /* deal with the user's key tracking and quota */
+ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
+ spin_lock(&key->user->lock);
+ key->user->qnkeys--;
+ key->user->qnbytes -= key->quotalen;
+ spin_unlock(&key->user->lock);
+ }
+
+ atomic_dec(&key->user->nkeys);
+ if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
+ atomic_dec(&key->user->nikeys);
+
+ key_user_put(key->user);
+
+ /* now throw away the key memory */
+ if (key->type->destroy)
+ key->type->destroy(key);
+
+ kfree(key->description);
+
+#ifdef KEY_DEBUGGING
+ key->magic = KEY_DEBUG_MAGIC_X;
+#endif
+ kmem_cache_free(key_jar, key);
+
+ /* there may, of course, be more than one key to destroy */
+ goto go_again;
+}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index f375152a250..a7cd1a68232 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -75,6 +75,7 @@ extern unsigned key_quota_maxbytes;
#define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */
+extern struct kmem_cache *key_jar;
extern struct rb_root key_serial_tree;
extern spinlock_t key_serial_lock;
extern struct mutex key_construction_mutex;
@@ -146,6 +147,7 @@ extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
extern long join_session_keyring(const char *name);
+extern struct work_struct key_gc_unused_work;
extern unsigned key_gc_delay;
extern void keyring_gc(struct key *keyring, time_t limit);
extern void key_schedule_gc(time_t expiry_at);
diff --git a/security/keys/key.c b/security/keys/key.c
index f7f9d93f08d..991a15f1e85 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -21,7 +21,7 @@
#include <linux/user_namespace.h>
#include "internal.h"
-static struct kmem_cache *key_jar;
+struct kmem_cache *key_jar;
struct rb_root key_serial_tree; /* tree of keys indexed by serial */
DEFINE_SPINLOCK(key_serial_lock);
@@ -36,9 +36,6 @@ unsigned int key_quota_maxbytes = 20000; /* general key space quota */
static LIST_HEAD(key_types_list);
static DECLARE_RWSEM(key_types_sem);
-static void key_cleanup(struct work_struct *work);
-static DECLARE_WORK(key_cleanup_task, key_cleanup);
-
/* We serialise key instantiation and link */
DEFINE_MUTEX(key_construction_mutex);
@@ -591,71 +588,6 @@ int key_reject_and_link(struct key *key,
}
EXPORT_SYMBOL(key_reject_and_link);
-/*
- * Garbage collect keys in process context so that we don't have to disable
- * interrupts all over the place.
- *
- * key_put() schedules this rather than trying to do the cleanup itself, which
- * means key_put() doesn't have to sleep.
- */
-static void key_cleanup(struct work_struct *work)
-{
- struct rb_node *_n;
- struct key *key;
-
-go_again:
- /* look for a dead key in the tree */
- spin_lock(&key_serial_lock);
-
- for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
- key = rb_entry(_n, struct key, serial_node);
-
- if (atomic_read(&key->usage) == 0)
- goto found_dead_key;
- }
-
- spin_unlock(&key_serial_lock);
- return;
-
-found_dead_key:
- /* we found a dead key - once we've removed it from the tree, we can
- * drop the lock */
- rb_erase(&key->serial_node, &key_serial_tree);
- spin_unlock(&key_serial_lock);
-
- key_check(key);
-
- security_key_free(key);
-
- /* deal with the user's key tracking and quota */
- if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
- spin_lock(&key->user->lock);
- key->user->qnkeys--;
- key->user->qnbytes -= key->quotalen;
- spin_unlock(&key->user->lock);
- }
-
- atomic_dec(&key->user->nkeys);
- if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
- atomic_dec(&key->user->nikeys);
-
- key_user_put(key->user);
-
- /* now throw away the key memory */
- if (key->type->destroy)
- key->type->destroy(key);
-
- kfree(key->description);
-
-#ifdef KEY_DEBUGGING
- key->magic = KEY_DEBUG_MAGIC_X;
-#endif
- kmem_cache_free(key_jar, key);
-
- /* there may, of course, be more than one key to destroy */
- goto go_again;
-}
-
/**
* key_put - Discard a reference to a key.
* @key: The key to discard a reference from.
@@ -670,7 +602,7 @@ void key_put(struct key *key)
key_check(key);
if (atomic_dec_and_test(&key->usage))
- schedule_work(&key_cleanup_task);
+ schedule_work(&key_gc_unused_work);
}
}
EXPORT_SYMBOL(key_put);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-01 00:45:55 +0000