diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-01-08 09:35:51 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-01-10 22:58:03 -0500 |
| commit | 3e4006f0b86a5ae5eb0e8215f9a9e1db24506977 (patch) | |
| tree | 46041d98779ad4d94052a8460a5fa558a6e5e712 /net | |
| parent | 320f1a4a175e7cd5d3f006f92b4d4d3e2cbb7bb5 (diff) | |
ipv6: tcp: add rcu locking in tcp_v6_send_synack()
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>
Diffstat (limited to 'net')
| -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 6b8a8a9091fa..bd100b47c717 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -462,8 +462,10 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, if (np->repflow && ireq->pktopts) fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); + rcu_read_lock(); err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass); + rcu_read_unlock(); err = net_xmit_eval(err); } |