5.4-stable review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche bvanassche@acm.org
commit aee2424246f9f1dadc33faa78990c1e2eb7826e4 upstream.
iw_conn_req_handler() associates a new struct rdma_id_private (conn_id) with an existing struct iw_cm_id (cm_id) as follows:
conn_id->cm_id.iw = cm_id; cm_id->context = conn_id; cm_id->cm_handler = cma_iw_handler;
rdma_destroy_id() frees both the cm_id and the struct rdma_id_private. Make sure that cm_work_handler() does not trigger a use-after-free by only freeing of the struct rdma_id_private after all pending work has finished.
Cc: stable@vger.kernel.org Fixes: 59c68ac31e15 ("iw_cm: free cm_id resources on the last deref") Reviewed-by: Zhu Yanjun yanjun.zhu@linux.dev Tested-by: Shin'ichiro Kawasaki shinichiro.kawasaki@wdc.com Signed-off-by: Bart Van Assche bvanassche@acm.org Link: https://lore.kernel.org/r/20240605145117.397751-6-bvanassche@acm.org Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/core/iwcm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/drivers/infiniband/core/iwcm.c +++ b/drivers/infiniband/core/iwcm.c @@ -370,8 +370,10 @@ EXPORT_SYMBOL(iw_cm_disconnect); * * Clean up all resources associated with the connection and release * the initial reference taken by iw_create_cm_id. + * + * Returns true if and only if the last cm_id_priv reference has been dropped. */ -static void destroy_cm_id(struct iw_cm_id *cm_id) +static bool destroy_cm_id(struct iw_cm_id *cm_id) { struct iwcm_id_private *cm_id_priv; struct ib_qp *qp; @@ -441,7 +443,7 @@ static void destroy_cm_id(struct iw_cm_i iwpm_remove_mapping(&cm_id->local_addr, RDMA_NL_IWCM); }
- (void)iwcm_deref_id(cm_id_priv); + return iwcm_deref_id(cm_id_priv); }
/* @@ -452,7 +454,8 @@ static void destroy_cm_id(struct iw_cm_i */ void iw_destroy_cm_id(struct iw_cm_id *cm_id) { - destroy_cm_id(cm_id); + if (!destroy_cm_id(cm_id)) + flush_workqueue(iwcm_wq); } EXPORT_SYMBOL(iw_destroy_cm_id);
@@ -1036,7 +1039,7 @@ static void cm_work_handler(struct work_ if (!test_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags)) { ret = process_event(cm_id_priv, &levent); if (ret) - destroy_cm_id(&cm_id_priv->id); + WARN_ON_ONCE(destroy_cm_id(&cm_id_priv->id)); } else pr_debug("dropping event %d\n", levent.event); if (iwcm_deref_id(cm_id_priv))