Bluetooth: hci_core: Avoid mixing up req_complete and req_complete_skb

In commit 44d271377479 ("Bluetooth: Compress the size of struct
hci_ctrl") we squashed down the size of the structure by using a union
with the assumption that all users would use the flag to determine
whether we had a req_complete or a req_complete_skb.

Unfortunately we had a case in hci_req_cmd_complete() where we weren't
looking at the flag.  This can result in a situation where we might be
storing a hci_req_complete_skb_t in a hci_req_complete_t variable, or
vice versa.

During some testing I found at least one case where the function
hci_req_sync_complete() was called improperly because the kernel thought
that it didn't require an SKB.  Looking through the stack in kgdb I
found that it was called by hci_event_packet() and that
hci_event_packet() had both of its locals "req_complete" and
"req_complete_skb" pointing to the same place: both to
hci_req_sync_complete().

Let's make sure we always check the flag.

For more details on debugging done, see <http://crbug.com/588288>.

Fixes: 44d271377479 ("Bluetooth: Compress the size of struct hci_ctrl")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 47bcef7547967ce544ff0cf5ea7dabecdd080d90..883c821a9e784851a89c00e3874b7d9da9628a69 100644 (file)
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -4112,8 +4112,10 @@ void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status,
                        break;
                }
 
-               *req_complete = bt_cb(skb)->hci.req_complete;
-               *req_complete_skb = bt_cb(skb)->hci.req_complete_skb;
+               if (bt_cb(skb)->hci.req_flags & HCI_REQ_SKB)
+                       *req_complete_skb = bt_cb(skb)->hci.req_complete_skb;
+               else
+                       *req_complete = bt_cb(skb)->hci.req_complete;
                kfree_skb(skb);
        }
        spin_unlock_irqrestore(&hdev->cmd_q.lock, flags);