2020-08-14 20:08:03

by Sonny Sasaka

[permalink] [raw]
Subject: [PATCH v2] Bluetooth: Fix auto-creation of hci_conn at Conn Complete event

Currently the code auto-creates hci_conn only if the remote address has
been discovered before. This may not be the case. For example, the
remote device may trigger connection after reboot at already-paired
state so there is no inquiry result found, but it is still correct to
create the hci_conn when Connection Complete event is received.

A better guard is to check against bredr allowlist. Devices in the
allowlist have been given permission to auto-connect.

Fixes: 4f40afc6c764 ("Bluetooth: Handle BR/EDR devices during suspend")
Signed-off-by: Sonny Sasaka <[email protected]>
Reviewed-by: Abhishek Pandit-Subedi <[email protected]>

---
net/bluetooth/hci_event.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 33d8458fdd4a..6b83da1790ee 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2566,7 +2566,6 @@ static void hci_inquiry_result_evt(struct hci_dev *hdev, struct sk_buff *skb)
static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
struct hci_ev_conn_complete *ev = (void *) skb->data;
- struct inquiry_entry *ie;
struct hci_conn *conn;

BT_DBG("%s", hdev->name);
@@ -2575,13 +2574,19 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)

conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
if (!conn) {
- /* Connection may not exist if auto-connected. Check the inquiry
- * cache to see if we've already discovered this bdaddr before.
- * If found and link is an ACL type, create a connection class
+ /* Connection may not exist if auto-connected. Check the bredr
+ * allowlist to see if this device is allowed to auto connect.
+ * If link is an ACL type, create a connection class
* automatically.
+ *
+ * Auto-connect will only occur if the event filter is
+ * programmed with a given address. Right now, event filter is
+ * only used during suspend.
*/
- ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
- if (ie && ev->link_type == ACL_LINK) {
+ if (ev->link_type == ACL_LINK &&
+ hci_bdaddr_list_lookup_with_flags(&hdev->whitelist,
+ &ev->bdaddr,
+ BDADDR_BREDR)) {
conn = hci_conn_add(hdev, ev->link_type, &ev->bdaddr,
HCI_ROLE_SLAVE);
if (!conn) {
--
2.26.2


2020-09-16 22:41:33

by Sonny Sasaka

[permalink] [raw]
Subject: Re: [PATCH v2] Bluetooth: Fix auto-creation of hci_conn at Conn Complete event

Dear maintainers,

Friendly ping to review this patch. Thanks!

On Fri, Aug 14, 2020 at 12:09 PM Sonny Sasaka <[email protected]> wrote:
>
> Currently the code auto-creates hci_conn only if the remote address has
> been discovered before. This may not be the case. For example, the
> remote device may trigger connection after reboot at already-paired
> state so there is no inquiry result found, but it is still correct to
> create the hci_conn when Connection Complete event is received.
>
> A better guard is to check against bredr allowlist. Devices in the
> allowlist have been given permission to auto-connect.
>
> Fixes: 4f40afc6c764 ("Bluetooth: Handle BR/EDR devices during suspend")
> Signed-off-by: Sonny Sasaka <[email protected]>
> Reviewed-by: Abhishek Pandit-Subedi <[email protected]>
>
> ---
> net/bluetooth/hci_event.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 33d8458fdd4a..6b83da1790ee 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -2566,7 +2566,6 @@ static void hci_inquiry_result_evt(struct hci_dev *hdev, struct sk_buff *skb)
> static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
> {
> struct hci_ev_conn_complete *ev = (void *) skb->data;
> - struct inquiry_entry *ie;
> struct hci_conn *conn;
>
> BT_DBG("%s", hdev->name);
> @@ -2575,13 +2574,19 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
>
> conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
> if (!conn) {
> - /* Connection may not exist if auto-connected. Check the inquiry
> - * cache to see if we've already discovered this bdaddr before.
> - * If found and link is an ACL type, create a connection class
> + /* Connection may not exist if auto-connected. Check the bredr
> + * allowlist to see if this device is allowed to auto connect.
> + * If link is an ACL type, create a connection class
> * automatically.
> + *
> + * Auto-connect will only occur if the event filter is
> + * programmed with a given address. Right now, event filter is
> + * only used during suspend.
> */
> - ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
> - if (ie && ev->link_type == ACL_LINK) {
> + if (ev->link_type == ACL_LINK &&
> + hci_bdaddr_list_lookup_with_flags(&hdev->whitelist,
> + &ev->bdaddr,
> + BDADDR_BREDR)) {
> conn = hci_conn_add(hdev, ev->link_type, &ev->bdaddr,
> HCI_ROLE_SLAVE);
> if (!conn) {
> --
> 2.26.2
>

2020-09-20 06:24:00

by Marcel Holtmann

[permalink] [raw]
Subject: Re: [PATCH v2] Bluetooth: Fix auto-creation of hci_conn at Conn Complete event

Hi Sonny,

> Currently the code auto-creates hci_conn only if the remote address has
> been discovered before. This may not be the case. For example, the
> remote device may trigger connection after reboot at already-paired
> state so there is no inquiry result found, but it is still correct to
> create the hci_conn when Connection Complete event is received.
>
> A better guard is to check against bredr allowlist. Devices in the
> allowlist have been given permission to auto-connect.
>
> Fixes: 4f40afc6c764 ("Bluetooth: Handle BR/EDR devices during suspend")
> Signed-off-by: Sonny Sasaka <[email protected]>
> Reviewed-by: Abhishek Pandit-Subedi <[email protected]>
>
> ---
> net/bluetooth/hci_event.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel