Commits
Jason Gunthorpe committed 4c499dafdd6
RDMA/cm: Fix ordering of xa_alloc_cyclic() in ib_create_cm_id() commit e8dc4e885c459343970b25acd9320fe9ee5492e7 upstream. xa_alloc_cyclic() is a SMP release to be paired with some later acquire during xa_load() as part of cm_acquire_id(). As such, xa_alloc_cyclic() must be done after the cm_id is fully initialized, in particular, it absolutely must be after the refcount_set(), otherwise the refcount_inc() in cm_acquire_id() may not see the set. As there are several cases where a reader will be able to use the id.local_id after cm_acquire_id in the IB_CM_IDLE state there needs to be an unfortunate split into a NULL allocate and a finalizing xa_store. Fixes: a977049dacde ("[PATCH] IB: Add the kernel CM implementation") Link: https://lore.kernel.org/r/20200310092545.251365-2-leon@kernel.org Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>