From: Zhengping Jiang jiangzp@google.com
[ Upstream commit 1857c19941c87eb36ad47f22a406be5dfe5eff9f ]
When the HCI_UNREGISTER flag is set, no jobs should be scheduled. Fix potential race when HCI_UNREGISTER is set after the flag is tested in hci_cmd_sync_queue.
Fixes: 0b94f2651f56 ("Bluetooth: hci_sync: Fix queuing commands when HCI_UNREGISTER is set") Signed-off-by: Zhengping Jiang jiangzp@google.com Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/bluetooth/hci_core.h | 1 + net/bluetooth/hci_core.c | 2 ++ net/bluetooth/hci_sync.c | 20 ++++++++++++++------ 3 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 86db7f3a31ce5..b973ecb222f65 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -514,6 +514,7 @@ struct hci_dev { struct work_struct cmd_sync_work; struct list_head cmd_sync_work_list; struct mutex cmd_sync_work_lock; + struct mutex unregister_lock; struct work_struct cmd_sync_cancel_work; struct work_struct reenable_adv_work;
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 334e308451f53..ac36e7ae70b21 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2685,7 +2685,9 @@ void hci_unregister_dev(struct hci_dev *hdev) { BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);
+ mutex_lock(&hdev->unregister_lock); hci_dev_set_flag(hdev, HCI_UNREGISTER); + mutex_unlock(&hdev->unregister_lock);
write_lock(&hci_dev_list_lock); list_del(&hdev->list); diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index b65ee3a32e5d7..fd3b6d79a7f8b 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -629,6 +629,7 @@ void hci_cmd_sync_init(struct hci_dev *hdev) INIT_WORK(&hdev->cmd_sync_work, hci_cmd_sync_work); INIT_LIST_HEAD(&hdev->cmd_sync_work_list); mutex_init(&hdev->cmd_sync_work_lock); + mutex_init(&hdev->unregister_lock);
INIT_WORK(&hdev->cmd_sync_cancel_work, hci_cmd_sync_cancel_work); INIT_WORK(&hdev->reenable_adv_work, reenable_adv); @@ -688,14 +689,19 @@ int hci_cmd_sync_queue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func, void *data, hci_cmd_sync_work_destroy_t destroy) { struct hci_cmd_sync_work_entry *entry; + int err = 0;
- if (hci_dev_test_flag(hdev, HCI_UNREGISTER)) - return -ENODEV; + mutex_lock(&hdev->unregister_lock); + if (hci_dev_test_flag(hdev, HCI_UNREGISTER)) { + err = -ENODEV; + goto unlock; + }
entry = kmalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return -ENOMEM; - + if (!entry) { + err = -ENOMEM; + goto unlock; + } entry->func = func; entry->data = data; entry->destroy = destroy; @@ -706,7 +712,9 @@ int hci_cmd_sync_queue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
queue_work(hdev->req_workqueue, &hdev->cmd_sync_work);
- return 0; +unlock: + mutex_unlock(&hdev->unregister_lock); + return err; } EXPORT_SYMBOL(hci_cmd_sync_queue);