This is a note to let you know that I've just added the patch titled tcp: fix wraparound issue in tcp_lp to the 3.18-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: tcp-fix-wraparound-issue-in-tcp_lp.patch and it can be found in the queue-3.18 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 Thu May 11 12:38:23 CEST 2017 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Mon, 1 May 2017 15:29:48 -0700 Subject: tcp: fix wraparound issue in tcp_lp From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit a9f11f963a546fea9144f6a6d1a307e814a387e7 ] Be careful when comparing tcp_time_stamp to some u32 quantity, otherwise result can be surprising. Fixes: 7c106d7e782b ("[TCP]: TCP Low Priority congestion control") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/tcp_lp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/ipv4/tcp_lp.c +++ b/net/ipv4/tcp_lp.c @@ -264,13 +264,15 @@ static void tcp_lp_pkts_acked(struct soc { struct tcp_sock *tp = tcp_sk(sk); struct lp *lp = inet_csk_ca(sk); + u32 delta; if (rtt_us > 0) tcp_lp_rtt_sample(sk, rtt_us); /* calc inference */ - if (tcp_time_stamp > tp->rx_opt.rcv_tsecr) - lp->inference = 3 * (tcp_time_stamp - tp->rx_opt.rcv_tsecr); + delta = tcp_time_stamp - tp->rx_opt.rcv_tsecr; + if ((s32)delta > 0) + lp->inference = 3 * delta; /* test if within inference */ if (lp->last_drop && (tcp_time_stamp - lp->last_drop < lp->inference)) Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-3.18/tcp-do-not-underestimate-skb-truesize-in-tcp_trim_head.patch queue-3.18/tcp-fix-wraparound-issue-in-tcp_lp.patch