From: Steve Wise Date: Tue, 4 Mar 2008 22:44:52 +0000 (-0600) Subject: RDMA/iwcm: Don't access a cm_id after dropping reference X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=d7c1fbd6606085dbf95e47068d6bd2db8a180e38;p=deliverable%2Flinux.git RDMA/iwcm: Don't access a cm_id after dropping reference cm_work_handler() can access cm_id_priv after it drops its reference by calling iwch_deref_id(), which might cause it to be freed. The fix is to look at whether IWCM_F_CALLBACK_DESTROY is set _before_ dropping the reference. Then if it was set, free the cm_id on this thread. Signed-off-by: Steve Wise Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c index 223b1aa7d92b..81c9195b512a 100644 --- a/drivers/infiniband/core/iwcm.c +++ b/drivers/infiniband/core/iwcm.c @@ -839,6 +839,7 @@ static void cm_work_handler(struct work_struct *_work) unsigned long flags; int empty; int ret = 0; + int destroy_id; spin_lock_irqsave(&cm_id_priv->lock, flags); empty = list_empty(&cm_id_priv->work_list); @@ -857,9 +858,9 @@ static void cm_work_handler(struct work_struct *_work) destroy_cm_id(&cm_id_priv->id); } BUG_ON(atomic_read(&cm_id_priv->refcount)==0); + destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags); if (iwcm_deref_id(cm_id_priv)) { - if (test_bit(IWCM_F_CALLBACK_DESTROY, - &cm_id_priv->flags)) { + if (destroy_id) { BUG_ON(!list_empty(&cm_id_priv->work_list)); free_cm_id(cm_id_priv); }