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.reshet...@intel.com>
Signed-off-by: Hans Liljestrand <ishkam...@gmail.com>
Signed-off-by: Kees Cook <keesc...@chromium.org>
Signed-off-by: David Windsor <dwind...@gmail.com>
---
include/net/if_inet6.h | 2 +-
net/ipv6/mcast.c | 18 +++++++++---------
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 2b41cb8..4bb52ce 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -127,7 +127,7 @@ struct ifmcaddr6 {
struct timer_list mca_timer;
unsigned int mca_flags;
int mca_users;
- atomic_t mca_refcnt;
+ refcount_t mca_refcnt;
spinlock_t mca_lock;
unsigned long mca_cstamp;
unsigned long mca_tstamp;
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index e222113..12b7c27 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -701,7 +701,7 @@ static void igmp6_group_dropped(struct ifmcaddr6 *mc)
spin_lock_bh(&mc->mca_lock);
if (del_timer(&mc->mca_timer))
- atomic_dec(&mc->mca_refcnt);
+ refcount_dec(&mc->mca_refcnt);
spin_unlock_bh(&mc->mca_lock);
}
@@ -819,12 +819,12 @@ static void mld_clear_delrec(struct inet6_dev *idev)
static void mca_get(struct ifmcaddr6 *mc)
{
- atomic_inc(&mc->mca_refcnt);
+ refcount_inc(&mc->mca_refcnt);
}
static void ma_put(struct ifmcaddr6 *mc)
{
- if (atomic_dec_and_test(&mc->mca_refcnt)) {
+ if (refcount_dec_and_test(&mc->mca_refcnt)) {
in6_dev_put(mc->idev);
kfree(mc);
}
@@ -846,7 +846,7 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
mc->mca_users = 1;
/* mca_stamp should be updated upon changes */
mc->mca_cstamp = mc->mca_tstamp = jiffies;
- atomic_set(&mc->mca_refcnt, 1);
+ refcount_set(&mc->mca_refcnt, 1);
spin_lock_init(&mc->mca_lock);
/* initial mode is (EX, empty) */
@@ -1065,7 +1065,7 @@ static void igmp6_group_queried(struct ifmcaddr6 *ma,
unsigned long resptime)
return;
if (del_timer(&ma->mca_timer)) {
- atomic_dec(&ma->mca_refcnt);
+ refcount_dec(&ma->mca_refcnt);
delay = ma->mca_timer.expires - jiffies;
}
@@ -1074,7 +1074,7 @@ static void igmp6_group_queried(struct ifmcaddr6 *ma,
unsigned long resptime)
ma->mca_timer.expires = jiffies + delay;
if (!mod_timer(&ma->mca_timer, jiffies + delay))
- atomic_inc(&ma->mca_refcnt);
+ refcount_inc(&ma->mca_refcnt);
ma->mca_flags |= MAF_TIMER_RUNNING;
}
@@ -1469,7 +1469,7 @@ int igmp6_event_report(struct sk_buff *skb)
if (ipv6_addr_equal(&ma->mca_addr, &mld->mld_mca)) {
spin_lock(&ma->mca_lock);
if (del_timer(&ma->mca_timer))
- atomic_dec(&ma->mca_refcnt);
+ refcount_dec(&ma->mca_refcnt);
ma->mca_flags &= ~(MAF_LAST_REPORTER|MAF_TIMER_RUNNING);
spin_unlock(&ma->mca_lock);
break;
@@ -2391,12 +2391,12 @@ static void igmp6_join_group(struct ifmcaddr6 *ma)
spin_lock_bh(&ma->mca_lock);
if (del_timer(&ma->mca_timer)) {
- atomic_dec(&ma->mca_refcnt);
+ refcount_dec(&ma->mca_refcnt);
delay = ma->mca_timer.expires - jiffies;
}
if (!mod_timer(&ma->mca_timer, jiffies + delay))
- atomic_inc(&ma->mca_refcnt);
+ refcount_inc(&ma->mca_refcnt);
ma->mca_flags |= MAF_TIMER_RUNNING | MAF_LAST_REPORTER;
spin_unlock_bh(&ma->mca_lock);
}
--
2.7.4
