From: Johan Hedberg <johan.hedberg@xxxxxxxxx>
The smp_distribute_keys() function calls smp_notify_keys() which in turn
calls l2cap_conn_update_id_addr(). The l2cap_conn_update_id_addr()
function will iterate through all L2CAP channels for the respective
connection: lock the channel, update the address information and unlock
the channel.
Since SMP is now using l2cap_chan callbacks each callback is called with
the channel lock held. Therefore, calling l2cap_conn_update_id_addr()
would cause a deadlock calling l2cap_chan_lock() on the SMP channel.
This patch moves calling smp_distribute_keys() through a workqueue so
that it is never called from an L2CAP channel callback.
Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx>
---
net/bluetooth/smp.c | 42 ++++++++++++++++++++++++++----------------
1 file changed, 26 insertions(+), 16 deletions(-)
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index cdae40869447..312ea5ec2d7d 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -46,6 +46,7 @@ enum {
struct smp_chan {
struct l2cap_conn *conn;
struct delayed_work security_timer;
+ struct work_struct distribute_work;
u8 preq[7]; /* SMP Pairing Request */
u8 prsp[7]; /* SMP Pairing Response */
@@ -656,11 +657,12 @@ static void smp_notify_keys(struct l2cap_conn *conn)
}
}
-static int smp_distribute_keys(struct l2cap_conn *conn)
+static void smp_distribute_keys(struct work_struct *work)
{
+ struct smp_chan *smp = container_of(work, struct smp_chan,
+ distribute_work);
struct smp_cmd_pairing *req, *rsp;
- struct l2cap_chan *chan = conn->smp;
- struct smp_chan *smp = chan->data;
+ struct l2cap_conn *conn = smp->conn;
struct hci_conn *hcon = conn->hcon;
struct hci_dev *hdev = hcon->hdev;
__u8 *keydist;
@@ -668,13 +670,13 @@ static int smp_distribute_keys(struct l2cap_conn *conn)
BT_DBG("conn %p", conn);
if (!test_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
- return 0;
+ return;
rsp = (void *) &smp->prsp[1];
/* The responder sends its keys first */
if (hcon->out && (smp->remote_key_dist & 0x07))
- return 0;
+ return;
req = (void *) &smp->preq[1];
@@ -760,15 +762,13 @@ static int smp_distribute_keys(struct l2cap_conn *conn)
/* If there are still keys to be received wait for them */
if ((smp->remote_key_dist & 0x07))
- return 0;
+ return;
clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags);
set_bit(SMP_FLAG_COMPLETE, &smp->flags);
smp_notify_keys(conn);
smp_chan_destroy(conn);
-
- return 0;
}
static void smp_timeout(struct work_struct *work)
@@ -804,6 +804,7 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
smp->conn = conn;
chan->data = smp;
+ INIT_WORK(&smp->distribute_work, smp_distribute_keys);
INIT_DELAYED_WORK(&smp->security_timer, smp_timeout);
hci_conn_hold(conn->hcon);
@@ -824,6 +825,12 @@ void smp_chan_destroy(struct l2cap_conn *conn)
if (!chan->data)
return;
+ if (work_pending(&smp->distribute_work)) {
+ cancel_work_sync(&smp->distribute_work);
+ if (!chan->data)
+ return;
+ }
+
complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
mgmt_smp_complete(conn->hcon, complete);
@@ -1287,7 +1294,7 @@ static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
rp->ediv, rp->rand);
smp->ltk = ltk;
if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
- smp_distribute_keys(conn);
+ queue_work(hdev->workqueue, &smp->distribute_work);
hci_dev_unlock(hdev);
return 0;
@@ -1322,6 +1329,7 @@ static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
struct l2cap_chan *chan = conn->smp;
struct smp_chan *smp = chan->data;
struct hci_conn *hcon = conn->hcon;
+ struct hci_dev *hdev = hcon->hdev;
bdaddr_t rpa;
BT_DBG("");
@@ -1364,7 +1372,7 @@ static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
smp->id_addr_type, smp->irk, &rpa);
distribute:
- smp_distribute_keys(conn);
+ queue_work(hdev->workqueue, &smp->distribute_work);
hci_dev_unlock(hcon->hdev);
@@ -1400,7 +1408,7 @@ static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb)
memcpy(csrk->val, rp->csrk, sizeof(csrk->val));
}
smp->csrk = csrk;
- smp_distribute_keys(conn);
+ queue_work(hdev->workqueue, &smp->distribute_work);
hci_dev_unlock(hdev);
return 0;
@@ -1510,7 +1518,6 @@ done:
static void smp_teardown_cb(struct l2cap_chan *chan, int err)
{
struct l2cap_conn *conn = chan->conn;
- struct smp_chan *smp = chan->data;
BT_DBG("chan %p", chan);
@@ -1526,14 +1533,17 @@ static void smp_resume_cb(struct l2cap_chan *chan)
struct smp_chan *smp = chan->data;
struct l2cap_conn *conn = chan->conn;
struct hci_conn *hcon = conn->hcon;
+ struct hci_dev *hdev = hcon->hdev;
BT_DBG("chan %p", chan);
- if (test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
- smp_distribute_keys(conn);
+ if (!smp)
+ return;
- if (smp)
- cancel_delayed_work(&smp->security_timer);
+ cancel_delayed_work(&smp->security_timer);
+
+ if (test_bit(HCI_CONN_ENCRYPT, &hcon->flags))
+ queue_work(hdev->workqueue, &smp->distribute_work);
}
static void smp_ready_cb(struct l2cap_chan *chan)
--
1.9.3
--
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