linux-kernel - [PATCH 01/18] net, llc: convert llc_sap.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: <1489749179-12063-2-git-send-email-elena.reshetova@intel.com>
Date:   Fri, 17 Mar 2017 13:12:42 +0200
From:   Elena Reshetova <elena.reshetova@...el.com>
To:     netdev@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org,
        linux-decnet-user@...ts.sourceforge.net, davem@...emloft.net,
        jmorris@...ei.org, kaber@...sh.net, yoshfuji@...ux-ipv6.org,
        kuznet@....inr.ac.ru, 3chas3@...il.com, ralf@...ux-mips.org,
        stephen@...workplumber.org, jchapman@...alix.com, jhs@...atatu.com,
        bridge@...ts.linux-foundation.org, linux-hams@...r.kernel.org,
        linux-x25@...r.kernel.org, linux-bluetooth@...r.kernel.org,
        marcel@...tmann.org, johan.hedberg@...il.com, peterz@...radead.org,
        keescook@...omium.org, Elena Reshetova <elena.reshetova@...el.com>,
        Hans Liljestrand <ishkamiel@...il.com>,
        David Windsor <dwindsor@...il.com>
Subject: [PATCH 01/18] net, llc: convert llc_sap.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/llc.h  | 6 +++---
 net/llc/llc_core.c | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/net/llc.h b/include/net/llc.h
index e8e61d4..dc35f25 100644
--- a/include/net/llc.h
+++ b/include/net/llc.h
@@ -55,7 +55,7 @@ struct llc_sap {
 	unsigned char	 state;
 	unsigned char	 p_bit;
 	unsigned char	 f_bit;
-	atomic_t         refcnt;
+	refcount_t		 refcnt;
 	int		 (*rcv_func)(struct sk_buff *skb,
 				     struct net_device *dev,
 				     struct packet_type *pt,
@@ -113,14 +113,14 @@ struct llc_sap *llc_sap_open(unsigned char lsap,
 					struct net_device *orig_dev));
 static inline void llc_sap_hold(struct llc_sap *sap)
 {
-	atomic_inc(&sap->refcnt);
+	refcount_inc(&sap->refcnt);
 }
 
 void llc_sap_close(struct llc_sap *sap);
 
 static inline void llc_sap_put(struct llc_sap *sap)
 {
-	if (atomic_dec_and_test(&sap->refcnt))
+	if (refcount_dec_and_test(&sap->refcnt))
 		llc_sap_close(sap);
 }
 
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c
index 842851c..8904126 100644
--- a/net/llc/llc_core.c
+++ b/net/llc/llc_core.c
@@ -41,7 +41,7 @@ static struct llc_sap *llc_sap_alloc(void)
 		spin_lock_init(&sap->sk_lock);
 		for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++)
 			INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i);
-		atomic_set(&sap->refcnt, 1);
+		refcount_set(&sap->refcnt, 1);
 	}
 	return sap;
 }
-- 
2.7.4