| Message ID | 1479719317-22437-1-git-send-email-fw@strlen.de |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Florian Westphal <fw@strlen.de> Date: Mon, 21 Nov 2016 10:08:37 +0100 > We need to zero out the private data area when application switches > connection to different algorithm (TCP_CONGESTION setsockopt). > > When congestion ops get assigned at connect time everything is already > zeroed because sk_alloc uses GFP_ZERO flag. But in the setsockopt case > this contains whatever previous cc placed there. > > Signed-off-by: Florian Westphal <fw@strlen.de> Good catch, applied, thanks Florian.
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index 1294af4e0127..f9038d6b109e 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -200,8 +200,10 @@ static void tcp_reinit_congestion_control(struct sock *sk, icsk->icsk_ca_ops = ca; icsk->icsk_ca_setsockopt = 1; - if (sk->sk_state != TCP_CLOSE) + if (sk->sk_state != TCP_CLOSE) { + memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv)); tcp_init_congestion_control(sk); + } } /* Manage refcounts on socket close. */
We need to zero out the private data area when application switches connection to different algorithm (TCP_CONGESTION setsockopt). When congestion ops get assigned at connect time everything is already zeroed because sk_alloc uses GFP_ZERO flag. But in the setsockopt case this contains whatever previous cc placed there. Signed-off-by: Florian Westphal <fw@strlen.de> --- net/ipv4/tcp_cong.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)