tcp: Fix a connect() race with timewait sockets
First patch changes __inet_hash_nolisten() and __inet6_hash()
to get a timewait parameter to be able to unhash it from ehash
at same time the new socket is inserted in hash.
This makes sure timewait socket wont be found by a concurrent
writer in __inet_check_established()
Reported-by: kapil dakhane <kdakhane@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index c813e29..633a6c2 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -22,9 +22,10 @@
#include <net/inet6_hashtables.h>
#include <net/ip.h>
-void __inet6_hash(struct sock *sk)
+int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
{
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+ int twrefcnt = 0;
WARN_ON(!sk_unhashed(sk));
@@ -45,10 +46,15 @@
lock = inet_ehash_lockp(hashinfo, hash);
spin_lock(lock);
__sk_nulls_add_node_rcu(sk, list);
+ if (tw) {
+ WARN_ON(sk->sk_hash != tw->tw_hash);
+ twrefcnt = inet_twsk_unhash(tw);
+ }
spin_unlock(lock);
}
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+ return twrefcnt;
}
EXPORT_SYMBOL(__inet6_hash);