From a0767da7774d91a668f9c223cec3e76172cd833b Mon Sep 17 00:00:00 2001 From: Michael Guralnik Date: Wed, 12 Feb 2020 09:26:31 +0200 Subject: [PATCH] RDMA/core: Add missing list deletion on freeing event queue When the uobject file scheme was revised to allow device disassociation from the file it became possible for read() to still happen the driver destroys the uobject. The old clode code was not tolerant to concurrent read, and when it was moved to the driver destroy it creates a bug. Ensure the event_list is empty after driver destroy by adding the missing list_del(). Otherwise read() can trigger a use after free and double kfree. Fixes: f7c8416ccea5 ("RDMA/core: Simplify destruction of FD uobjects") Link: https://lore.kernel.org/r/20200212072635.682689-6-leon@kernel.org Signed-off-by: Michael Guralnik Reviewed-by: Yishai Hadas Signed-off-by: Leon Romanovsky Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/uverbs_std_types.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/infiniband/core/uverbs_std_types.c b/drivers/infiniband/core/uverbs_std_types.c index 994d8744b246..3abfc63225cb 100644 --- a/drivers/infiniband/core/uverbs_std_types.c +++ b/drivers/infiniband/core/uverbs_std_types.c @@ -220,6 +220,7 @@ void ib_uverbs_free_event_queue(struct ib_uverbs_event_queue *event_queue) list_for_each_entry_safe(entry, tmp, &event_queue->event_list, list) { if (entry->counter) list_del(&entry->obj_list); + list_del(&entry->list); kfree(entry); } spin_unlock_irq(&event_queue->lock);