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From: Elena Reshetova <elena.reshetova@intel.com>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, linux-rdma@vger.kernel.org,
	linux-hams@vger.kernel.org, linux-ppp@vger.kernel.org,
	ganeshgr@chelsio.com, nbd@openwrt.org, john@phrozen.org,
	sean.wang@mediatek.com, matthias.bgg@gmail.com,
	yishaih@mellanox.com, saeedm@mellanox.com, matanb@mellanox.com,
	tariqt@mellanox.com, leonro@mellanox.com,
	ajk@comnets.uni-bremen.de, paulus@samba.org, zbr@ioremap.net,
	peterz@infradead.org, keescook@chromium.org,
	Elena Reshetova <elena.reshetova@intel.com>
Subject: [PATCH 11/15] drivers, net: convert masces_tx_sa.refcnt from atomic_t to refcount_t
Date: Fri, 20 Oct 2017 07:23:45 +0000	[thread overview]
Message-ID: <1508484229-19706-12-git-send-email-elena.reshetova@intel.com> (raw)
In-Reply-To: <1508484229-19706-1-git-send-email-elena.reshetova@intel.com>

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>
---
 drivers/net/macsec.c | 8 ++++----
 1 file 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;
-- 
2.7.4


  parent reply	other threads:[~2017-10-20  7:23 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-20  7:23 [PATCH 00/15] networking drivers refcount_t conversions Elena Reshetova
2017-10-20  7:23 ` [PATCH 01/15] drivers, net, ethernet: convert clip_entry.refcnt from atomic_t to refcount_t Elena Reshetova
2017-10-20  7:23 ` [PATCH 02/15] drivers, net, ethernet: convert mtk_eth.dma_refcnt " Elena Reshetova
     [not found]   ` <1508484229-19706-3-git-send-email-elena.reshetova-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-10-20  8:08     ` Sean Wang
2017-10-20 10:37       ` Reshetova, Elena
2017-10-22  4:06         ` Sean Wang
2017-10-23  6:37           ` Reshetova, Elena
2017-10-20  7:23 ` [PATCH 03/15] drivers, net, mlx4: convert mlx4_cq.refcount " Elena Reshetova
     [not found] ` <1508484229-19706-1-git-send-email-elena.reshetova-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-10-20  7:23   ` [PATCH 04/15] drivers, net, mlx4: convert mlx4_qp.refcount " Elena Reshetova
2017-10-20  7:23 ` [PATCH 05/15] drivers, net, mlx4: convert mlx4_srq.refcount " Elena Reshetova
2017-10-20  7:23 ` [PATCH 06/15] drivers, net, mlx5: convert mlx5_cq.refcount " Elena Reshetova
2017-10-20  7:23 ` [PATCH 07/15] drivers, net, mlx5: convert fs_node.refcount " Elena Reshetova
2017-10-20  7:23 ` [PATCH 08/15] drivers, net, hamradio: convert sixpack.refcnt " Elena Reshetova
2017-10-20  7:23 ` [PATCH 09/15] drivers, net: convert masces_rx_sa.refcnt " Elena Reshetova
2017-10-20  7:23 ` [PATCH 10/15] drivers, net: convert masces_rx_sc.refcnt " Elena Reshetova
2017-10-20  7:23 ` Elena Reshetova [this message]
2017-10-20  7:23 ` [PATCH 12/15] drivers, net, ppp: convert asyncppp.refcnt " Elena Reshetova
2017-10-20  7:23 ` [PATCH 13/15] drivers, net, ppp: convert ppp_file.refcnt " Elena Reshetova
2017-10-20  7:23 ` [PATCH 14/15] drivers, net, ppp: convert syncppp.refcnt " Elena Reshetova
2017-10-20  7:23 ` [PATCH 15/15] drivers, connector: convert cn_callback_entry.refcnt " Elena Reshetova
2017-10-22  1:31 ` [PATCH 00/15] networking drivers refcount_t conversions David Miller
2017-10-23  6:34   ` Reshetova, Elena

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