The field adv_instance_cnt is always accessed within a device lock,
except in the function add_advertising. A concurrent remove of an
advertisement with adding another one could result in the if check
"if a new instance was actually added" to not trigger, resulting
in not triggering the "advertising added event".
Signed-off-by: Niels Dossche <[email protected]>
---
net/bluetooth/mgmt.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 37087cf7dc5a..e0dc72f147b4 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -8046,7 +8046,7 @@ static int add_advertising(struct sock *sk, struct hci_dev *hdev,
u32 flags;
u8 status;
u16 timeout, duration;
- unsigned int prev_instance_cnt = hdev->adv_instance_cnt;
+ unsigned int prev_instance_cnt;
u8 schedule_instance = 0;
struct adv_info *next_instance;
int err;
@@ -8097,6 +8097,8 @@ static int add_advertising(struct sock *sk, struct hci_dev *hdev,
goto unlock;
}
+ prev_instance_cnt = hdev->adv_instance_cnt;
+
err = hci_add_adv_instance(hdev, cp->instance, flags,
cp->adv_data_len, cp->data,
cp->scan_rsp_len,
--
2.34.1