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author | Elena Reshetova <elena.reshetova@intel.com> | 2017-10-20 10:23:45 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-10-22 02:22:39 +0100 |
commit | 28206cdb3bc079a97d24c33b4427395f9e406fad (patch) | |
tree | ccfef81625bbe98a5632d1ef314b7deb7f9185bb /drivers | |
parent | 8676d76f087f9b2499f056aa0c5d857cffde6806 (diff) | |
download | op-kernel-dev-28206cdb3bc079a97d24c33b4427395f9e406fad.zip op-kernel-dev-28206cdb3bc079a97d24c33b4427395f9e406fad.tar.gz |
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 'drivers')
-rw-r--r-- | drivers/net/macsec.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index e0aeb51..8948b6a 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); spin_lock_init(&tx_sa->lock); return 0; |