From: Michael Guralnik Date: Wed, 12 Feb 2020 07:26:31 +0000 (+0200) Subject: RDMA/core: Add missing list deletion on freeing event queue X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a0767da7774d91a668f9c223cec3e76172cd833b;p=linux.git 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 --- diff --git a/drivers/infiniband/core/uverbs_std_types.c b/drivers/infiniband/core/uverbs_std_types.c index 994d8744b2469..3abfc63225cbf 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);