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@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
include/net/fib_rules.h | 7 ++++---
net/core/fib_rules.c | 4 ++--
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 8dbfdf7..26ae0ad 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -5,6 +5,7 @@
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/fib_rules.h>
+#include <linux/refcount.h>
#include <net/flow.h>
#include <net/rtnetlink.h>
@@ -29,7 +30,7 @@ struct fib_rule {
struct fib_rule __rcu *ctarget;
struct net *fr_net;
- atomic_t refcnt;
+ refcount_t refcnt;
u32 pref;
int suppress_ifgroup;
int suppress_prefixlen;
@@ -103,12 +104,12 @@ struct fib_rules_ops {
static inline void fib_rule_get(struct fib_rule *rule)
{
- atomic_inc(&rule->refcnt);
+ refcount_inc(&rule->refcnt);
}
static inline void fib_rule_put(struct fib_rule *rule)
{
- if (atomic_dec_and_test(&rule->refcnt))
+ if (refcount_dec_and_test(&rule->refcnt))
kfree_rcu(rule, rcu);
}
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index b6791d9..53d55d5 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -32,7 +32,7 @@ int fib_default_rule_add(struct fib_rules_ops *ops,
if (r == NULL)
return -ENOMEM;
- atomic_set(&r->refcnt, 1);
+ refcount_set(&r->refcnt, 1);
r->action = FR_ACT_TO_TBL;
r->pref = pref;
r->table = table;
@@ -269,7 +269,7 @@ int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
if (err != -EAGAIN) {
if ((arg->flags & FIB_LOOKUP_NOREF) ||
- likely(atomic_inc_not_zero(&rule->refcnt))) {
+ likely(refcount_inc_not_zero(&rule->refcnt))) {
arg->rule = rule;
goto out;
}
--
2.7.4
