From a8af8694a5e8ddaaef4bd7b6426c12b7759c846c Mon Sep 17 00:00:00 2001 From: Yishai Hadas Date: Wed, 12 Feb 2020 09:26:32 +0200 Subject: RDMA/mlx5: Fix async events cleanup flows As in the prior patch, the devx code is not fully cleaning up its event_lists before finishing driver_destroy allowing a later read to trigger user after free conditions. Re-arrange things so that the event_list is always empty after destroy and ensure it remains empty until the file is closed. Fixes: f7c8416ccea5 ("RDMA/core: Simplify destruction of FD uobjects") Link: https://lore.kernel.org/r/20200212072635.682689-7-leon@kernel.org Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/mlx5/devx.c | 51 +++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 23 deletions(-) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c index d7efc9f6daf0..46e1ab771f10 100644 --- a/drivers/infiniband/hw/mlx5/devx.c +++ b/drivers/infiniband/hw/mlx5/devx.c @@ -2319,14 +2319,12 @@ static int deliver_event(struct devx_event_subscription *event_sub, if (ev_file->omit_data) { spin_lock_irqsave(&ev_file->lock, flags); - if (!list_empty(&event_sub->event_list)) { + if (!list_empty(&event_sub->event_list) || + ev_file->is_destroyed) { spin_unlock_irqrestore(&ev_file->lock, flags); return 0; } - /* is_destroyed is ignored here because we don't have any memory - * allocation to clean up for the omit_data case - */ list_add_tail(&event_sub->event_list, &ev_file->event_list); spin_unlock_irqrestore(&ev_file->lock, flags); wake_up_interruptible(&ev_file->poll_wait); @@ -2473,11 +2471,11 @@ static ssize_t devx_async_cmd_event_read(struct file *filp, char __user *buf, return -ERESTARTSYS; } - if (list_empty(&ev_queue->event_list) && - ev_queue->is_destroyed) - return -EIO; - spin_lock_irq(&ev_queue->lock); + if (ev_queue->is_destroyed) { + spin_unlock_irq(&ev_queue->lock); + return -EIO; + } } event = list_entry(ev_queue->event_list.next, @@ -2551,10 +2549,6 @@ static ssize_t devx_async_event_read(struct file *filp, char __user *buf, return -EOVERFLOW; } - if (ev_file->is_destroyed) { - spin_unlock_irq(&ev_file->lock); - return -EIO; - } while (list_empty(&ev_file->event_list)) { spin_unlock_irq(&ev_file->lock); @@ -2667,8 +2661,10 @@ static int devx_async_cmd_event_destroy_uobj(struct ib_uobject *uobj, spin_lock_irq(&comp_ev_file->ev_queue.lock); list_for_each_entry_safe(entry, tmp, - &comp_ev_file->ev_queue.event_list, list) + &comp_ev_file->ev_queue.event_list, list) { + list_del(&entry->list); kvfree(entry); + } spin_unlock_irq(&comp_ev_file->ev_queue.lock); return 0; }; @@ -2680,11 +2676,29 @@ static int devx_async_event_destroy_uobj(struct ib_uobject *uobj, container_of(uobj, struct devx_async_event_file, uobj); struct devx_event_subscription *event_sub, *event_sub_tmp; - struct devx_async_event_data *entry, *tmp; struct mlx5_ib_dev *dev = ev_file->dev; spin_lock_irq(&ev_file->lock); ev_file->is_destroyed = 1; + + /* free the pending events allocation */ + if (ev_file->omit_data) { + struct devx_event_subscription *event_sub, *tmp; + + list_for_each_entry_safe(event_sub, tmp, &ev_file->event_list, + event_list) + list_del_init(&event_sub->event_list); + + } else { + struct devx_async_event_data *entry, *tmp; + + list_for_each_entry_safe(entry, tmp, &ev_file->event_list, + list) { + list_del(&entry->list); + kfree(entry); + } + } + spin_unlock_irq(&ev_file->lock); wake_up_interruptible(&ev_file->poll_wait); @@ -2699,15 +2713,6 @@ static int devx_async_event_destroy_uobj(struct ib_uobject *uobj, } mutex_unlock(&dev->devx_event_table.event_xa_lock); - /* free the pending events allocation */ - if (!ev_file->omit_data) { - spin_lock_irq(&ev_file->lock); - list_for_each_entry_safe(entry, tmp, - &ev_file->event_list, list) - kfree(entry); /* read can't come any more */ - spin_unlock_irq(&ev_file->lock); - } - put_device(&dev->ib_dev.dev); return 0; }; -- cgit v1.2.3-59-g8ed1b