linux-kernel - [PATCH] Inet-hashtable: Change the range of sk->hash lock to avoid the race condition.

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-next>] [day] [month] [year] [list]

Message-ID: <1379003549.12328.6.camel@chenjun-workstation>
Date:	Thu, 12 Sep 2013 12:32:29 -0400
From:	Jun Chen <jun.d.chen@...el.com>
To:	edumazet@...gle.com
Cc:	davem@...emloft.net, eric.dumazet@...il.com,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jun Chen <jun.d.chen@...el.com>
Subject: [PATCH] Inet-hashtable: Change the range of sk->hash lock to avoid
 the race condition.


When try to add node to list in __inet_hash_nolisten function, first get the
list and then to lock for using, but in extremeness case, others can del this
node before locking it, then the node should be null.So this patch try to lock
firstly and then get the list for using to avoid this race condition.

Signed-off-by: Chen Jun <jun.d.chen@...el.com>
---
 net/ipv4/inet_hashtables.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 7bd8983..76e846e 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -407,12 +407,15 @@ int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw)
 	WARN_ON(!sk_unhashed(sk));
 
 	sk->sk_hash = inet_sk_ehashfn(sk);
-	head = inet_ehash_bucket(hashinfo, sk->sk_hash);
-	list = &head->chain;
 	lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 
 	spin_lock(lock);
-	__sk_nulls_add_node_rcu(sk, list);
+	if (sk_hashed(sk)) {
+		head = inet_ehash_bucket(hashinfo, sk->sk_hash);
+		list = &head->chain;
+		__sk_nulls_add_node_rcu(sk, list);
+	}
+
 	if (tw) {
 		WARN_ON(sk->sk_hash != tw->tw_hash);
 		twrefcnt = inet_twsk_unhash(tw);
-- 
1.7.4.1



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/