From 1d3648eb5d1fe9ed3d095ed8fa19ad11ca4c8bc0 Mon Sep 17 00:00:00 2001 From: Neal Cardwell Date: Fri, 14 Jul 2017 17:49:24 -0400 Subject: [PATCH] tcp_bbr: remove sk_pacing_rate=0 transient during init Fix a corner case noticed by Eric Dumazet, where BBR's setting sk->sk_pacing_rate to 0 during initialization could theoretically cause packets in the sending host to hang if there were packets "in flight" in the pacing infrastructure at the time the BBR congestion control state is initialized. This could occur if the pacing infrastructure happened to race with bbr_init() in a way such that the pacer read the 0 rather than the immediately following non-zero pacing rate. Fixes: 0f8782ea1497 ("tcp_bbr: add BBR congestion control") Reported-by: Eric Dumazet Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- net/ipv4/tcp_bbr.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c index 3276140..42e0017 100644 --- a/net/ipv4/tcp_bbr.c +++ b/net/ipv4/tcp_bbr.c @@ -837,7 +837,6 @@ static void bbr_init(struct sock *sk) minmax_reset(&bbr->bw, bbr->rtt_cnt, 0); /* init max bw to 0 */ - sk->sk_pacing_rate = 0; /* force an update of sk_pacing_rate */ bbr_init_pacing_rate_from_rtt(sk); bbr->restore_cwnd = 0; -- 2.7.4