From 433cea4d9bbb83cc848b80c51bb849a2ceb49379 Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Fri, 30 Jun 2017 13:08:04 +0300 Subject: [PATCH] net: convert netpoll_info.refcnt from atomic_t to refcount_t 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- 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 1828900c9411..27c0aaa22cb0 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -11,6 +11,7 @@ #include #include #include +#include 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 a835155c85f9..d3408a693166 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;