This is a note to let you know that I've just added the patch titled ipv6: tcp: add rcu locking in tcp_v6_send_synack() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-tcp-add-rcu-locking-in-tcp_v6_send_synack.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Jan 26 21:31:27 PST 2016 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Fri, 8 Jan 2016 09:35:51 -0800 Subject: ipv6: tcp: add rcu locking in tcp_v6_send_synack() From: Eric Dumazet <edumazet@xxxxxxxxxx> [ 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@xxxxxxxxxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/tcp_ipv6.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -462,8 +462,10 @@ static int tcp_v6_send_synack(const stru 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); } Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-4.4/ipv6-tcp-add-rcu-locking-in-tcp_v6_send_synack.patch queue-4.4/ipv6-update-skb-csum-when-ce-mark-is-propagated.patch queue-4.4/phonet-properly-unshare-skbs-in-phonet_rcv.patch queue-4.4/tcp_yeah-don-t-set-ssthresh-below-2.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html