From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This attempts to detect if HCI_EV_NUM_COMP_PKTS contain an unbalanced
(more than currently considered outstanding) number of packets otherwise
it could cause the hcon->sent to underflow and loop around breaking the
tracking of the outstanding packets pending acknowledgment.
Fixes: f42809185896 ("Bluetooth: Simplify num_comp_pkts_evt function")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
net/bluetooth/hci_event.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 512041c68062..dc946c5b59d8 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4414,7 +4414,17 @@ static void hci_num_comp_pkts_evt(struct hci_dev *hdev, void *data,
if (!conn)
continue;
- conn->sent -= count;
+ /* Check if there is really enough packets outstanding before
+ * attempting to decrease the sent counter otherwise it could
+ * underflow..
+ */
+ if (conn->sent >= count) {
+ conn->sent -= count;
+ } else {
+ bt_dev_warn(hdev, "hcon %p sent %u < count %u",
+ conn, conn->sent, count);
+ conn->sent = 0;
+ }
for (i = 0; i < count; ++i)
hci_conn_tx_dequeue(conn);
--
2.50.1
