path: root/drivers/net/macsec.c
diff options
authorElena Reshetova <elena.reshetova@intel.com>2017-10-20 10:23:44 +0300
committerDavid S. Miller <davem@davemloft.net>2017-10-22 02:22:39 +0100
commit8676d76f087f9b2499f056aa0c5d857cffde6806 (patch)
tree67bd8bcf2a6aadbd9192bbffd9865f83a1ccaf54 /drivers/net/macsec.c
parentdrivers, net: convert masces_rx_sa.refcnt from atomic_t to refcount_t (diff)
drivers, net: convert masces_rx_sc.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_rx_sc.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 733e1c240bf5..e0aeb51a5dab 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -172,7 +172,7 @@ struct macsec_rx_sc {
bool active;
struct macsec_rx_sa __rcu *sa[MACSEC_NUM_AN];
struct pcpu_rx_sc_stats __percpu *stats;
- atomic_t refcnt;
+ refcount_t refcnt;
struct rcu_head rcu_head;
@@ -331,12 +331,12 @@ static void free_rx_sc_rcu(struct rcu_head *head)
static struct macsec_rx_sc *macsec_rxsc_get(struct macsec_rx_sc *sc)
- return atomic_inc_not_zero(&sc->refcnt) ? sc : NULL;
+ return refcount_inc_not_zero(&sc->refcnt) ? sc : NULL;
static void macsec_rxsc_put(struct macsec_rx_sc *sc)
- if (atomic_dec_and_test(&sc->refcnt))
+ if (refcount_dec_and_test(&sc->refcnt))
call_rcu(&sc->rcu_head, free_rx_sc_rcu);
@@ -1411,7 +1411,7 @@ static struct macsec_rx_sc *create_rx_sc(struct net_device *dev, sci_t sci)
rx_sc->sci = sci;
rx_sc->active = true;
- atomic_set(&rx_sc->refcnt, 1);
+ refcount_set(&rx_sc->refcnt, 1);
secy = &macsec_priv(dev)->secy;
rcu_assign_pointer(rx_sc->next, secy->rx_sc);