From 1be9246077f6bb1583f9347c599480621d63c66a Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Tue, 4 Jul 2017 09:34:55 +0300 Subject: [PATCH] net, ipv6: convert inet6_dev.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/net/addrconf.h | 8 ++++---- include/net/if_inet6.h | 3 ++- net/ipv6/addrconf.c | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/net/addrconf.h b/include/net/addrconf.h index d0889cb50172..620bd9a83ba9 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -316,7 +316,7 @@ static inline struct inet6_dev *in6_dev_get(const struct net_device *dev) rcu_read_lock(); idev = rcu_dereference(dev->ip6_ptr); if (idev) - atomic_inc(&idev->refcnt); + refcount_inc(&idev->refcnt); rcu_read_unlock(); return idev; } @@ -332,18 +332,18 @@ void in6_dev_finish_destroy(struct inet6_dev *idev); static inline void in6_dev_put(struct inet6_dev *idev) { - if (atomic_dec_and_test(&idev->refcnt)) + if (refcount_dec_and_test(&idev->refcnt)) in6_dev_finish_destroy(idev); } static inline void __in6_dev_put(struct inet6_dev *idev) { - atomic_dec(&idev->refcnt); + refcount_dec(&idev->refcnt); } static inline void in6_dev_hold(struct inet6_dev *idev) { - atomic_inc(&idev->refcnt); + refcount_inc(&idev->refcnt); } void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp); diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index f656f9051aca..e7a17b231afc 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -17,6 +17,7 @@ #include #include +#include /* inet6_dev.if_flags */ @@ -187,7 +188,7 @@ struct inet6_dev { struct ifacaddr6 *ac_list; rwlock_t lock; - atomic_t refcnt; + refcount_t refcnt; __u32 if_flags; int dead; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 114fb64cf176..2365f1224c6b 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -426,7 +426,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) } /* One reference from device. */ - in6_dev_hold(ndev); + refcount_set(&ndev->refcnt, 1); if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) ndev->cnf.accept_dad = -1; -- 2.11.0