path: root/drivers/net/macsec.c
diff options
authorElena Reshetova <elena.reshetova@intel.com>2017-10-20 10:23:45 +0300
committerDavid S. Miller <davem@davemloft.net>2017-10-22 02:22:39 +0100
commit28206cdb3bc079a97d24c33b4427395f9e406fad (patch)
treeccfef81625bbe98a5632d1ef314b7deb7f9185bb /drivers/net/macsec.c
parentdrivers, net: convert masces_rx_sc.refcnt from atomic_t to refcount_t (diff)
drivers, net: convert masces_tx_sa.refcnt from atomic_t to refcount_t
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable masces_tx_sa.refcnt is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index e0aeb51a5dab..8948b6adc0c5 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -188,7 +188,7 @@ struct macsec_tx_sa {
struct macsec_key key;
spinlock_t lock;
u32 next_pn;
- atomic_t refcnt;
+ refcount_t refcnt;
bool active;
struct macsec_tx_sa_stats __percpu *stats;
struct rcu_head rcu;
@@ -362,7 +362,7 @@ static struct macsec_tx_sa *macsec_txsa_get(struct macsec_tx_sa __rcu *ptr)
if (!sa || !sa->active)
return NULL;
- if (!atomic_inc_not_zero(&sa->refcnt))
+ if (!refcount_inc_not_zero(&sa->refcnt))
return NULL;
return sa;
@@ -379,7 +379,7 @@ static void free_txsa(struct rcu_head *head)
static void macsec_txsa_put(struct macsec_tx_sa *sa)
- if (atomic_dec_and_test(&sa->refcnt))
+ if (refcount_dec_and_test(&sa->refcnt))
call_rcu(&sa->rcu, free_txsa);
@@ -1437,7 +1437,7 @@ static int init_tx_sa(struct macsec_tx_sa *tx_sa, char *sak, int key_len,
tx_sa->active = false;
- atomic_set(&tx_sa->refcnt, 1);
+ refcount_set(&tx_sa->refcnt, 1);
return 0;