lkml.org 
[lkml]   [2017]   [Jul]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5/9] net, ipv6: convert ifacaddr6.aca_refcnt from atomic_t to refcount_t
Date
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 <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
include/net/if_inet6.h | 2 +-
net/ipv6/anycast.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 4bb52ce..d4088d1 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -147,7 +147,7 @@ struct ifacaddr6 {
struct rt6_info *aca_rt;
struct ifacaddr6 *aca_next;
int aca_users;
- atomic_t aca_refcnt;
+ refcount_t aca_refcnt;
unsigned long aca_cstamp;
unsigned long aca_tstamp;
};
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 514ac25..0bbab8a 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -203,12 +203,12 @@ void ipv6_sock_ac_close(struct sock *sk)

static void aca_get(struct ifacaddr6 *aca)
{
- atomic_inc(&aca->aca_refcnt);
+ refcount_inc(&aca->aca_refcnt);
}

static void aca_put(struct ifacaddr6 *ac)
{
- if (atomic_dec_and_test(&ac->aca_refcnt)) {
+ if (refcount_dec_and_test(&ac->aca_refcnt)) {
in6_dev_put(ac->aca_idev);
dst_release(&ac->aca_rt->dst);
kfree(ac);
@@ -232,7 +232,7 @@ static struct ifacaddr6 *aca_alloc(struct rt6_info *rt,
aca->aca_users = 1;
/* aca_tstamp should be updated upon changes */
aca->aca_cstamp = aca->aca_tstamp = jiffies;
- atomic_set(&aca->aca_refcnt, 1);
+ refcount_set(&aca->aca_refcnt, 1);

return aca;
}
--
2.7.4
\
 
 \ /
  Last update: 2017-07-04 08:37    [W:0.069 / U:0.736 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site