| Message ID | 02374660836e1b52afc91966b7535c8c5f7bafb0.1731060874.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | mptcp: fix a couple of races | expand |
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 95a5a3da3944..48d480982b78 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2082,7 +2082,8 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) slow = lock_sock_fast(ssk); WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf); WRITE_ONCE(tcp_sk(ssk)->window_clamp, window_clamp); - tcp_cleanup_rbuf(ssk, 1); + if (tcp_can_send_ack(ssk)) + tcp_cleanup_rbuf(ssk, 1); unlock_sock_fast(ssk, slow); } }
Additional active subflows - i.e. created by the in kernel path manager - are included into the subflow list before starting the 3whs. A racing recvmsg() spooling data received on an already established subflow would unconditionally call tcp_cleanup_rbuf() on all the current subflows, potentially hitting a divide by zero error on the newly created ones. Explicitly check that the subflow is in a suitable state before invoking tcp_cleanup_rbuf(). Fixes: c76c6956566f ("mptcp: call tcp_cleanup_rbuf on subflows") Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/mptcp/protocol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)