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| author | Eric Dumazet <edumazet@google.com> | 2016-01-08 09:35:51 -0800 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-02-15 15:42:44 -0500 |
| commit | 51bd690f02ecda5e5e39c14d33dcb6db92ed101e (patch) | |
| tree | 76f8d0b0fc8ceeb599b13ed0667d16becbcbe166 /net | |
| parent | ea06dfa254fd787953340ebfa12517cc2836c2ca (diff) | |
| download | lwn-51bd690f02ecda5e5e39c14d33dcb6db92ed101e.tar.gz lwn-51bd690f02ecda5e5e39c14d33dcb6db92ed101e.zip | |
ipv6: tcp: add rcu locking in tcp_v6_send_synack()
[ Upstream commit 3e4006f0b86a5ae5eb0e8215f9a9e1db24506977 ]
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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
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 b5a4ac8ce4b1..78d180615495 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -502,8 +502,10 @@ 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); } |