diff options
| author | Davide Caratti <dcaratti@redhat.com> | 2020-07-15 22:27:05 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-07-17 12:47:00 -0700 |
| commit | 8c728940487945e25cdfe020d58da42143aa98c1 (patch) | |
| tree | a91470aed5e01dc3e32be9c994a0df56056dffd0 /net/mptcp | |
| parent | 79814d8179b3c62f700196dcbd6a2ca2bb0dd188 (diff) | |
| download | lwn-8c728940487945e25cdfe020d58da42143aa98c1.tar.gz lwn-8c728940487945e25cdfe020d58da42143aa98c1.zip | |
mptcp: silence warning in subflow_data_ready()
since commit d47a72152097 ("mptcp: fix race in subflow_data_ready()"), it
is possible to observe a regression in MP_JOIN kselftests. For sockets in
TCP_CLOSE state, it's not sufficient to just wake up the main socket: we
also need to ensure that received data are made available to the reader.
Silence the WARN_ON_ONCE() in these cases: it preserves the syzkaller fix
and restores kselftests when they are ran as follows:
# while true; do
> make KBUILD_OUTPUT=/tmp/kselftest TARGETS=net/mptcp kselftest
> done
Reported-by: Florian Westphal <fw@strlen.de>
Fixes: d47a72152097 ("mptcp: fix race in subflow_data_ready()")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/47
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/subflow.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 9f7f3772c13c..519122e66f17 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -869,18 +869,19 @@ void mptcp_space(const struct sock *ssk, int *space, int *full_space) static void subflow_data_ready(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); + u16 state = 1 << inet_sk_state_load(sk); struct sock *parent = subflow->conn; struct mptcp_sock *msk; msk = mptcp_sk(parent); - if ((1 << inet_sk_state_load(sk)) & (TCPF_LISTEN | TCPF_CLOSE)) { + if (state & TCPF_LISTEN) { set_bit(MPTCP_DATA_READY, &msk->flags); parent->sk_data_ready(parent); return; } WARN_ON_ONCE(!__mptcp_check_fallback(msk) && !subflow->mp_capable && - !subflow->mp_join); + !subflow->mp_join && !(state & TCPF_CLOSE)); if (mptcp_subflow_data_available(sk)) mptcp_data_ready(parent, sk); |