4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bart Van Assche <bvanassche@xxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 59c68ac31e15 ("iw_cm: free cm_id resources on the last deref")
Reviewed-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxx>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Link: https://lore.kernel.org/r/20240605145117.397751-6-bvanassche@xxxxxxx
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -369,8 +369,10 @@ 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;
unsigned long flags;
@@ -438,7 +440,7 @@ 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);
}
/*
@@ -449,7 +451,8 @@ 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);
@@ -1022,7 +1025,7 @@ 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))
