[PATCH 5.18 454/879] Bluetooth: use hdev lock for accept_list and reject_list in conn req

Greg Kroah-Hartman
2022-06-08T00:15:44Z

From: Niels Dossche <dossche.niels@gmail.com>

[ Upstream commit fb048cae51bacdfbbda2954af3c213fdb1d484f4 ]

All accesses (both reads and modifications) to
hdev->{accept,reject}_list are protected by hdev lock,
except the ones in hci_conn_request_evt. This can cause a race
condition in the form of a list corruption.
The solution is to protect these lists in hci_conn_request_evt as well.

I was unable to find the exact commit that introduced the issue for the
reject list, I was only able to find it for the accept list.

Fixes: a55bd29d5227 ("Bluetooth: Add white list lookup for incoming connection requests")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/hci_event.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 66451661283c..a835ce6f8430 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3225,10 +3225,12 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
return;
}

+ hci_dev_lock(hdev);
+
if (hci_bdaddr_list_lookup(&hdev->reject_list, &ev->bdaddr,
BDADDR_BREDR)) {
hci_reject_conn(hdev, &ev->bdaddr);
- return;
+ goto unlock;
}

/* Require HCI_CONNECTABLE or an accept list entry to accept the
@@ -3240,13 +3242,11 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
!hci_bdaddr_list_lookup_with_flags(&hdev->accept_list, &ev->bdaddr,
BDADDR_BREDR)) {
hci_reject_conn(hdev, &ev->bdaddr);
- return;
+ goto unlock;
}

/* Connection accepted */

- hci_dev_lock(hdev);
-
ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
if (ie)
memcpy(ie->data.dev_class, ev->dev_class, 3);
@@ -3258,8 +3258,7 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
HCI_ROLE_SLAVE);
if (!conn) {
bt_dev_err(hdev, "no memory for new connection");
- hci_dev_unlock(hdev);
- return;
+ goto unlock;
}
}

@@ -3299,6 +3298,10 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
conn->state = BT_CONNECT2;
hci_connect_cfm(conn, 0);
}
+
+ return;
+unlock:
+ hci_dev_unlock(hdev);
}

static u8 hci_to_mgmt_reason(u8 err)
--
2.35.1