| From | Chenbo Feng <> | Date | Mon, 9 Apr 2018 11:00:06 -0700 | Subject | Re: [PATCH AUTOSEL for 4.4 065/162] tcp: Add a tcp_filter hook before handle ack packet |
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On Sun, Apr 8, 2018 at 5:28 PM, Sasha Levin <Alexander.Levin@microsoft.com> wrote: > From: Chenbo Feng <fengc@google.com> > > [ Upstream commit 8fac365f63c866a00015fa13932d8ffc584518b8 ] > > Currently in both ipv4 and ipv6 code path, the ack packet received when > sk at TCP_NEW_SYN_RECV state is not filtered by socket filter or cgroup > filter since it is handled from tcp_child_process and never reaches the > tcp_filter inside tcp_v4_rcv or tcp_v6_rcv. Adding a tcp_filter hooks > here can make sure all the ingress tcp packet can be correctly filtered. > > Signed-off-by: Chenbo Feng <fengc@google.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> > --- > net/ipv4/tcp_ipv4.c | 2 ++ > net/ipv6/tcp_ipv6.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 61c93a93f228..2eb9a1747f25 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -1639,6 +1639,8 @@ process: > } > if (nsk == sk) { > reqsk_put(req); > + } else if (tcp_filter(sk, skb)) { > + goto discard_and_relse; > } else if (tcp_child_process(sk, nsk, skb)) { > tcp_v4_send_reset(nsk, skb); > goto discard_and_relse; > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c > index 74cbcc4b399c..7d7f0999a919 100644 > --- a/net/ipv6/tcp_ipv6.c > +++ b/net/ipv6/tcp_ipv6.c > @@ -1428,6 +1428,8 @@ process: > if (nsk == sk) { > reqsk_put(req); > tcp_v6_restore_cb(skb); > + } else if (tcp_filter(sk, skb)) { > + goto discard_and_relse; > } else if (tcp_child_process(sk, nsk, skb)) { > tcp_v6_send_reset(nsk, skb); > goto discard_and_relse; > -- > 2.15.1 There is a bug fix for this patch upstream: "d624d276d1ddacbcb12ad96832ce0c7b82cd25db tcp: fix possible deadlock in TCP stack vs BPF filter", Please make you include that as well if you want to add this patch to stable.
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