| Message ID | 1454508209-601-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
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); }
This is a note to let you know that I have just added a patch titled ipv6: tcp: add rcu locking in tcp_v6_send_synack() to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt24. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 2e0009900a7280500df2fe4a988caa5c24305d2a Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@google.com> Date: Fri, 8 Jan 2016 09:35:51 -0800 Subject: 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> --- net/ipv6/tcp_ipv6.c | 2 ++ 1 file changed, 2 insertions(+)