[PATCH 11/17] net: convert netpoll_info.refcnt from atomic_t to refcount_t
From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-06-28 11:58:31
Also in:
bridge, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- include/linux/netpoll.h | 3 ++- net/core/netpoll.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 1828900..27c0aaa 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h@@ -11,6 +11,7 @@ #include <linux/interrupt.h> #include <linux/rcupdate.h> #include <linux/list.h> +#include <linux/refcount.h> union inet_addr { __u32 all[4];
@@ -34,7 +35,7 @@ struct netpoll { }; struct netpoll_info { - atomic_t refcnt; + refcount_t refcnt; struct semaphore dev_lock;
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index e256cd8..59a08e5 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c@@ -632,7 +632,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) skb_queue_head_init(&npinfo->txq); INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); - atomic_set(&npinfo->refcnt, 1); + refcount_set(&npinfo->refcnt, 1); ops = np->dev->netdev_ops; if (ops->ndo_netpoll_setup) {
@@ -642,7 +642,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) } } else { npinfo = rtnl_dereference(ndev->npinfo); - atomic_inc(&npinfo->refcnt); + refcount_inc(&npinfo->refcnt); } npinfo->netpoll = np;
@@ -821,7 +821,7 @@ void __netpoll_cleanup(struct netpoll *np) synchronize_srcu(&netpoll_srcu); - if (atomic_dec_and_test(&npinfo->refcnt)) { + if (refcount_dec_and_test(&npinfo->refcnt)) { const struct net_device_ops *ops; ops = np->dev->netdev_ops;
--
2.7.4