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Bluetooth: hci_core: Avoid mixing up req_complete and req_complete_skb

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In commit 44d2713774 ("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: 44d2713774 ("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>
This commit is contained in:
Douglas Anderson 2016-02-19 14:25:21 -08:00 committed by Marcel Holtmann
parent d07c0278da
commit 3bd7594e69
1 changed files with 4 additions and 2 deletions
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6
net/bluetooth/hci_core.c
View file

@ -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);