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authorEric Dumazet <edumazet@google.com>2017-05-01 15:29:48 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-14 13:32:58 +0200
commit0b83310c6813412353a6c720434075ef0f3e0fcb (patch)
tree7b371d5130c9c6b71e8c310bc23b86a441f0f780 /net
parent6003cc55c1bd15017916c96e08e0b675b7abbc16 (diff)
tcp: fix wraparound issue in tcp_lp
[ 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@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_lp.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c
index 1e70fa8fa793..3861dedd5365 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, u32 num_acked, s32 rtt_us)
{
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))