From: Leon Romanovsky leonro@mellanox.com
commit ed7a01fd3fd77f40b4ef2562b966a5decd8928d2 upstream.
Tracking CM_ID resource is performed in two stages: creation of cm_id and connecting it to the cma_dev. It is needed because rdma-cm protocol exports two separate user-visible calls rdma_create_id and rdma_accept.
At the time of CM_ID creation, the real owner of that object is unknown yet and we need to grab task_struct. This task_struct is released or reassigned in attach phase later on. but call to rdma_destroy_id left this task_struct unreleased.
Such separation is unique to CM_ID and other restrack objects initialize in one shot. It means that it is safe to use "res->valid" check to catch unfinished CM_ID flow and release task_struct for that object.
Fixes: 00313983cda6 ("RDMA/nldev: provide detailed CM_ID information") Reported-by: Artemy Kovalyov artemyko@mellanox.com Reviewed-by: Artemy Kovalyov artemyko@mellanox.com Reviewed-by: Yossi Itigin yosefe@mellanox.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Reviewed-by: Steve Wise swise@opengridcomputing.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Cc: Håkon Bugge haakon.bugge@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/cma.c | 7 +++---- drivers/infiniband/core/restrack.c | 6 ++++-- 2 files changed, 7 insertions(+), 6 deletions(-)
--- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -1723,8 +1723,8 @@ void rdma_destroy_id(struct rdma_cm_id * mutex_lock(&id_priv->handler_mutex); mutex_unlock(&id_priv->handler_mutex);
+ rdma_restrack_del(&id_priv->res); if (id_priv->cma_dev) { - rdma_restrack_del(&id_priv->res); if (rdma_cap_ib_cm(id_priv->id.device, 1)) { if (id_priv->cm_id.ib) ib_destroy_cm_id(id_priv->cm_id.ib); @@ -3463,10 +3463,9 @@ int rdma_bind_addr(struct rdma_cm_id *id
return 0; err2: - if (id_priv->cma_dev) { - rdma_restrack_del(&id_priv->res); + rdma_restrack_del(&id_priv->res); + if (id_priv->cma_dev) cma_release_dev(id_priv); - } err1: cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_IDLE); return ret; --- a/drivers/infiniband/core/restrack.c +++ b/drivers/infiniband/core/restrack.c @@ -209,7 +209,7 @@ void rdma_restrack_del(struct rdma_restr struct ib_device *dev;
if (!res->valid) - return; + goto out;
dev = res_to_dev(res); if (!dev) @@ -222,8 +222,10 @@ void rdma_restrack_del(struct rdma_restr down_write(&dev->res.rwsem); hash_del(&res->node); res->valid = false; + up_write(&dev->res.rwsem); + +out: if (res->task) put_task_struct(res->task); - up_write(&dev->res.rwsem); } EXPORT_SYMBOL(rdma_restrack_del);