[PATCH 5.17 384/772] Bluetooth: use hdev lock in activate_scan for hci_is_adv_monitoring

Greg Kroah-Hartman
2022-06-07T21:12:08Z

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

[ Upstream commit 50a3633ae5e98cf1b80ef5b73c9e341aee9ad896 ]

hci_is_adv_monitoring's function documentation states that it must be
called under the hdev lock. Paths that leads to an unlocked call are:
discov_update => start_discovery => interleaved_discov => active_scan
and: discov_update => start_discovery => active_scan

The solution is to take the lock in active_scan during the duration of
the call to hci_is_adv_monitoring.

Fixes: c32d624640fd ("Bluetooth: disable filter dup when scan for adv monitor")
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_request.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 42c8047a9897..f4afe482e300 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -2260,6 +2260,7 @@ static int active_scan(struct hci_request *req, unsigned long opt)
if (err < 0)
own_addr_type = ADDR_LE_DEV_PUBLIC;

+ hci_dev_lock(hdev);
if (hci_is_adv_monitoring(hdev)) {
/* Duplicate filter should be disabled when some advertisement
* monitor is activated, otherwise AdvMon can only receive one
@@ -2276,6 +2277,7 @@ static int active_scan(struct hci_request *req, unsigned long opt)
*/
filter_dup = LE_SCAN_FILTER_DUP_DISABLE;
}
+ hci_dev_unlock(hdev);

hci_req_start_scan(req, LE_SCAN_ACTIVE, interval,
hdev->le_scan_window_discovery, own_addr_type,
--
2.35.1