diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-05-01 15:29:48 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-02 15:07:02 -0400 |
| commit | a9f11f963a546fea9144f6a6d1a307e814a387e7 (patch) | |
| tree | f0b2d91346ba97af27e4b5ba3cdaf8f4127d02f7 /net | |
| parent | ddc665a4bb4b728b4e6ecec8db1b64efa9184b9c (diff) | |
tcp: fix wraparound issue in tcp_lp
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@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_lp.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c index 046fd3910873..d6fb6c067af4 100644 --- a/net/ipv4/tcp_lp.c +++ b/net/ipv4/tcp_lp.c @@ -264,13 +264,15 @@ static void tcp_lp_pkts_acked(struct sock *sk, const struct ack_sample *sample) { struct tcp_sock *tp = tcp_sk(sk); struct lp *lp = inet_csk_ca(sk); + u32 delta; if (sample->rtt_us > 0) tcp_lp_rtt_sample(sk, sample->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)) |