diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-01-08 09:35:51 -0800 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2016-02-02 19:52:46 +0000 |
| commit | 2e0009900a7280500df2fe4a988caa5c24305d2a (patch) | |
| tree | bfc2f09ba1c0ed02ba3a4ccebd5a660bd77ce22e /net/ipv6/tcp_ipv6.c | |
| parent | 1b687f7e661aa0f55715c67f1b489aef9e29f70b (diff) | |
ipv6: tcp: add rcu locking in tcp_v6_send_synack()
commit 3e4006f0b86a5ae5eb0e8215f9a9e1db24506977 upstream.
When first SYNACK is sent, we already hold rcu_read_lock(), but this
is not true if a SYNACK is retransmitted, as a timer (soft) interrupt
does not hold rcu_read_lock()
Fixes: 45f6fad84cc30 ("ipv6: add complete rcu protection around np->opt")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 9a87a208732e..2350f12eb318 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -497,8 +497,10 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst, fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); skb_set_queue_mapping(skb, queue_mapping); + rcu_read_lock(); err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass); + rcu_read_unlock(); err = net_xmit_eval(err); } |