BugLink: https://bugs.launchpad.net/bugs/1868628

commit c14dfddb upstream.

The algorithm pre-allocates a cm_id since allocation cannot be done while
holding the cm.lock spinlock, however it doesn't free it on one error
path, leading to a memory leak.

Fixes: 067b171b ("IB/cm: Share listening CM IDs")
Link: https://lore.kernel.org/r/20200221152023.GA8680@ziepe.caSigned-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>