2015-08-19 14:05:29

by Nicholas Krause

Subject: [PATCH] bluetooth:Fix error checking in the function hci_disconn_complete_evt

This fixes error checking in the function hci_disconn_complete_evt
to properly check if it's call to the function hci_remove_link_key
returns NULL to signal it has not correctly removed the link key
on the passed hci_dev structure pointer and if so jump to the goto
label unlock to unlock the caller's passed hci_dev structure pointer
as this function cannot continue its intended work after this failed

Signed-off-by: Nicholas Krause <[email protected]>
---
net/bluetooth/hci_event.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 32363c2..5174649 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2448,8 +2448,10 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
reason, mgmt_connected);

if (conn->type == ACL_LINK) {
- if (test_bit(HCI_CONN_FLUSH_KEY, &conn->flags))
- hci_remove_link_key(hdev, &conn->dst);
+ if (test_bit(HCI_CONN_FLUSH_KEY, &conn->flags)) {
+ if (!hci_remove_link_key(hdev, &conn->dst))
+ goto unlock;
+ }

hci_update_page_scan(hdev);
}
--
2.1.4

2015-08-24 09:47:49

by Johan Hedberg

Subject: Re: [PATCH] bluetooth:Fix error checking in the function hci_disconn_complete_evt

Hi Nicholas,

On Wed, Aug 19, 2015, Nicholas Krause wrote:
> This fixes error checking in the function hci_disconn_complete_evt
> to properly check if it's call to the function hci_remove_link_key
> returns NULL to signal it has not correctly removed the link key
> on the passed hci_dev structure pointer and if so jump to the goto
> label unlock to unlock the caller's passed hci_dev structure pointer
> as this function cannot continue its intended work after this failed
>
> Signed-off-by: Nicholas Krause <[email protected]>
> ---
> net/bluetooth/hci_event.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 32363c2..5174649 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -2448,8 +2448,10 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
> reason, mgmt_connected);
>
> if (conn->type == ACL_LINK) {
> - if (test_bit(HCI_CONN_FLUSH_KEY, &conn->flags))
> - hci_remove_link_key(hdev, &conn->dst);
> + if (test_bit(HCI_CONN_FLUSH_KEY, &conn->flags)) {
> + if (!hci_remove_link_key(hdev, &conn->dst))
> + goto unlock;
> + }
>
> hci_update_page_scan(hdev);
> }

This doesn't look correct to me. The only scenario where
hci_remove_link_key() may fail is if there was no existing key (it'll
return -ENOENT then). This is a perfectly normal thing that will occur
for a disconnection of a non-paired device, so any other cleanups like
hci_update_page_scan() should still go ahead.

Johan