| Message ID | 1502181718.4487.9.camel@edumazet-glaptop3.roam.corp.google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Aug 8, 2017 at 1:41 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > From: Eric Dumazet <edumazet@google.com> > > With new TCP_FASTOPEN_CONNECT socket option, there is a possibility > to call tcp_connect() while socket sk_dst_cache is either NULL > or invalid. > > +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 > +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 > +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0 > +0 connect(4, ..., ...) = 0 > > << sk->sk_dst_cache becomes obsolete, or even set to NULL >> > > +1 sendto(4, ..., 1000, MSG_FASTOPEN, ..., ...) = 1000 > > > We need to refresh the route otherwise bad things can happen, > especially when syzkaller is running on the host :/ > > Fixes: 19f6d3f3c8422 ("net/tcp-fastopen: Add new API support") > Reported-by: Dmitry Vyukov <dvyukov@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Wei Wang <weiwan@google.com> > Cc: Yuchung Cheng <ycheng@google.com> > --- Thanks a lot for the fix, Eric. Acked-by: Wei Wang <weiwan@google.com>
On Tue, Aug 8, 2017 at 1:41 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > From: Eric Dumazet <edumazet@google.com> > > With new TCP_FASTOPEN_CONNECT socket option, there is a possibility > to call tcp_connect() while socket sk_dst_cache is either NULL > or invalid. > > +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 > +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 > +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0 > +0 connect(4, ..., ...) = 0 > > << sk->sk_dst_cache becomes obsolete, or even set to NULL >> > > +1 sendto(4, ..., 1000, MSG_FASTOPEN, ..., ...) = 1000 > > > We need to refresh the route otherwise bad things can happen, > especially when syzkaller is running on the host :/ > > Fixes: 19f6d3f3c8422 ("net/tcp-fastopen: Add new API support") > Reported-by: Dmitry Vyukov <dvyukov@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Wei Wang <weiwan@google.com> > Cc: Yuchung Cheng <ycheng@google.com> > --- Acked-by: Yuchung Cheng <ycheng@google.com> Thanks for the fix! > net/ipv4/tcp_output.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index 276406a83a37..b7661a68d498 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -3436,6 +3436,10 @@ int tcp_connect(struct sock *sk) > int err; > > tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB); > + > + if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk)) > + return -EHOSTUNREACH; /* Routing failure or similar. */ > + > tcp_connect_init(sk); > > if (unlikely(tp->repair)) { > >
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Tue, 08 Aug 2017 01:41:58 -0700 > From: Eric Dumazet <edumazet@google.com> > > With new TCP_FASTOPEN_CONNECT socket option, there is a possibility > to call tcp_connect() while socket sk_dst_cache is either NULL > or invalid. > > +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 > +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 > +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0 > +0 connect(4, ..., ...) = 0 > > << sk->sk_dst_cache becomes obsolete, or even set to NULL >> > > +1 sendto(4, ..., 1000, MSG_FASTOPEN, ..., ...) = 1000 > > > We need to refresh the route otherwise bad things can happen, > especially when syzkaller is running on the host :/ > > Fixes: 19f6d3f3c8422 ("net/tcp-fastopen: Add new API support") > Reported-by: Dmitry Vyukov <dvyukov@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> Applied and queued up for -stable.
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 276406a83a37..b7661a68d498 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3436,6 +3436,10 @@ int tcp_connect(struct sock *sk) int err; tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB); + + if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk)) + return -EHOSTUNREACH; /* Routing failure or similar. */ + tcp_connect_init(sk); if (unlikely(tp->repair)) {