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authorElena Reshetova <elena.reshetova@intel.com>2017-03-31 15:20:48 +0300
committerJames Morris <james.l.morris@oracle.com>2017-04-03 10:49:05 +1000
commitfff292914d3a2f1efd05ca71c2ba72a3c663201e (patch)
tree627f9870ad82da8f6f06cca86a73e3b7e2fc97d5 /security/keys/key.c
parent8291798dcf059cdc5e55a59b2c4ad70ae14508c2 (diff)
security, keys: convert key.usage from atomic_t to refcount_t
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'security/keys/key.c')
-rw-r--r--security/keys/key.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/security/keys/key.c b/security/keys/key.c
index 346fbf201c22..ff9244392d35 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -285,7 +285,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
if (!key->index_key.description)
goto no_memory_3;
- atomic_set(&key->usage, 1);
+ refcount_set(&key->usage, 1);
init_rwsem(&key->sem);
lockdep_set_class(&key->sem, &type->lock_class);
key->index_key.type = type;
@@ -621,7 +621,7 @@ void key_put(struct key *key)
if (key) {
key_check(key);
- if (atomic_dec_and_test(&key->usage))
+ if (refcount_dec_and_test(&key->usage))
schedule_work(&key_gc_work);
}
}
@@ -656,7 +656,7 @@ not_found:
found:
/* pretend it doesn't exist if it is awaiting deletion */
- if (atomic_read(&key->usage) == 0)
+ if (refcount_read(&key->usage) == 0)
goto not_found;
/* this races with key_put(), but that doesn't matter since key_put()