linux-kernel - [PATCH 12/23] net, x25: convert x25_neigh.refcnt from atomic_t to refcount

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1489752646-8749-13-git-send-email-elena.reshetova@intel.com>
Date:   Fri, 17 Mar 2017 14:10:35 +0200
From:   Elena Reshetova <elena.reshetova@...el.com>
To:     netdev@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, linux-rdma@...r.kernel.org,
        davem@...emloft.net, linux-x25@...r.kernel.org,
        linux-sctp@...r.kernel.org, vyasevich@...il.com,
        nhorman@...driver.com, linux-hams@...r.kernel.org,
        linux-nfs@...r.kernel.org, ceph-devel@...r.kernel.org,
        zyan@...hat.com, sage@...hat.com, bfields@...ldses.org,
        jlayton@...chiereds.net, steffen.klassert@...unet.com,
        herbert@...dor.apana.org.au, santosh.shilimkar@...cle.com,
        jreuter@...na.de, ralf@...ux-mips.org, peterz@...radead.org,
        keescook@...omium.org, Elena Reshetova <elena.reshetova@...el.com>,
        Hans Liljestrand <ishkamiel@...il.com>,
        David Windsor <dwindsor@...il.com>
Subject: [PATCH 12/23] net, x25: convert x25_neigh.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 <elena.reshetova@...el.com>
Signed-off-by: Hans Liljestrand <ishkamiel@...il.com>
Signed-off-by: Kees Cook <keescook@...omium.org>
Signed-off-by: David Windsor <dwindsor@...il.com>
---
 include/net/x25.h  | 6 +++---
 net/x25/x25_link.c | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/net/x25.h b/include/net/x25.h
index 83a6d31..265756c 100644
--- a/include/net/x25.h
+++ b/include/net/x25.h
@@ -142,7 +142,7 @@ struct x25_neigh {
 	unsigned long		t20;
 	struct timer_list	t20timer;
 	unsigned long		global_facil_mask;
-	atomic_t		refcnt;
+	refcount_t		refcnt;
 };
 
 struct x25_sock {
@@ -243,12 +243,12 @@ void x25_link_free(void);
 /* x25_neigh.c */
 static __inline__ void x25_neigh_hold(struct x25_neigh *nb)
 {
-	atomic_inc(&nb->refcnt);
+	refcount_inc(&nb->refcnt);
 }
 
 static __inline__ void x25_neigh_put(struct x25_neigh *nb)
 {
-	if (atomic_dec_and_test(&nb->refcnt))
+	if (refcount_dec_and_test(&nb->refcnt))
 		kfree(nb);
 }
 
diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c
index bcaa180..e0cd04d 100644
--- a/net/x25/x25_link.c
+++ b/net/x25/x25_link.c
@@ -266,7 +266,7 @@ void x25_link_device_up(struct net_device *dev)
 				       X25_MASK_PACKET_SIZE |
 				       X25_MASK_WINDOW_SIZE;
 	nb->t20      = sysctl_x25_restart_request_timeout;
-	atomic_set(&nb->refcnt, 1);
+	refcount_set(&nb->refcnt, 1);
 
 	write_lock_bh(&x25_neigh_list_lock);
 	list_add(&nb->node, &x25_neigh_list);
-- 
2.7.4