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authorPaolo Abeni <pabeni@redhat.com>2023-02-07 16:04:16 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-02-14 21:11:51 +0300
commitba36772a1cc94a70e55942c049b2e33fc482ff99 (patch)
tree98ed54029f8d0c6adf20487f2841ea9afcadd51f /net/mptcp
parente266ad04ec3993244b663303e3d2281524bb1732 (diff)
downloadlinux-ba36772a1cc94a70e55942c049b2e33fc482ff99.tar.xz
mptcp: be careful on subflow status propagation on errors
commit 1249db44a102d9d3541ed7798d4b01ffdcf03524 upstream. Currently the subflow error report callback unconditionally propagates the fallback subflow status to the owning msk. If the msk is already orphaned, the above prevents the code from correctly tracking the msk moving to the TCP_CLOSE state and doing the appropriate cleanup. All the above causes increasing memory usage over time and sporadic self-tests failures. There is a great deal of infrastructure trying to propagate correctly the fallback subflow status to the owning mptcp socket, e.g. via mptcp_subflow_eof() and subflow_sched_work_if_closed(): in the error propagation path we need only to cope with unorphaned sockets. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/339 Fixes: 15cc10453398 ("mptcp: deliver ssk errors to msk") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/subflow.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 5220435d8e34..929b0ee8b3d5 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1344,6 +1344,7 @@ void __mptcp_error_report(struct sock *sk)
mptcp_for_each_subflow(msk, subflow) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
int err = sock_error(ssk);
+ int ssk_state;
if (!err)
continue;
@@ -1354,7 +1355,14 @@ void __mptcp_error_report(struct sock *sk)
if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(msk))
continue;
- inet_sk_state_store(sk, inet_sk_state_load(ssk));
+ /* We need to propagate only transition to CLOSE state.
+ * Orphaned socket will see such state change via
+ * subflow_sched_work_if_closed() and that path will properly
+ * destroy the msk as needed.
+ */
+ ssk_state = inet_sk_state_load(ssk);
+ if (ssk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DEAD))
+ inet_sk_state_store(sk, ssk_state);
sk->sk_err = -err;
/* This barrier is coupled with smp_rmb() in mptcp_poll() */