commit f00432063db1a0db484e85193eccc6845435b80e upstream. We must ensure that all sockets are closed before we call xprt_free() and release the reference to the net namespace. The problem is that calling fput() will defer closing the socket until delayed_fput() gets called. Let's fix the situation by allowing rpciod and the transport teardown code (which runs on the system wq) to call __fput_sync(), and directly close the socket. Reported-by: Felix Fu <foyjog@gmail.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Fixes: a73881c96d73 ("SUNRPC: Fix an Oops in udp_poll()") Cc: stable@vger.kernel.org # 5.1.x: 3be232f11a3c: SUNRPC: Prevent immediate close+reconnect Cc: stable@vger.kernel.org # 5.1.x: 89f42494f92f: SUNRPC: Don't call connect() more than once on a TCP socket Cc: stable@vger.kernel.org # 5.1.x Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Meena Shanmugam <meenashanmugam@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>