From: Leon Romanovsky <leonro@xxxxxxxxxx> Change location of rdma_restrack_del() to fix the bug where task_struct was acquired but not released, causing to resource leak. ucma_create_id() { ucma_alloc_ctx(); rdma_create_user_id() { rdma_restrack_new(); rdma_restrack_set_name() { rdma_restrack_attach_task.part.0(); <--- task_struct was gotten } } ucma_destroy_private_ctx() { ucma_put_ctx(); rdma_destroy_id() { _destroy_id() <--- id_priv was freed } } } Fixes: 889d916b6f8a ("RDMA/core: Don't access cm_id after its destruction") Reported-by: Pavel Skripkin <paskripkin@xxxxxxxxx> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx> --- --- Changelog: v3: * Dropped controversial hunks and updated commit message respectively v2: https://lore.kernel.org/lkml/e2eed941f912b2068e371fd37f43b8cf5082a0e6.1623129597.git.leonro@xxxxxxxxxx * Added bug report analysis v1: https://lore.kernel.org/linux-rdma/f72e27d5c82cd9beec7670141afa62786836c569.1622956637.git.leonro@xxxxxxxxxx/T/#u --- drivers/infiniband/core/cma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index ab148a696c0c..6d103c42bbec 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -1852,6 +1852,7 @@ static void _destroy_id(struct rdma_id_private *id_priv, { cma_cancel_operation(id_priv, state); + rdma_restrack_del(&id_priv->res); if (id_priv->cma_dev) { if (rdma_cap_ib_cm(id_priv->id.device, 1)) { if (id_priv->cm_id.ib) @@ -1861,7 +1862,6 @@ static void _destroy_id(struct rdma_id_private *id_priv, iw_destroy_cm_id(id_priv->cm_id.iw); } cma_leave_mc_groups(id_priv); - rdma_restrack_del(&id_priv->res); cma_release_dev(id_priv); } -- 2.31.1