From: Dean Jenkins <Dean_Jenkins@xxxxxxxxxx> Add a timeout to prevent the do while loop running in an infinite loop. This ensures that the channel will be instructed to close within 10 seconds so prevents l2cap_sock_shutdown() getting stuck forever. Returns -ENOLINK when the timeout is reached. The channel will be subequently closed and not all data will be ACK'ed. Signed-off-by: Dean Jenkins <Dean_Jenkins@xxxxxxxxxx> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> --- include/net/bluetooth/l2cap.h | 1 + net/bluetooth/l2cap_sock.c | 11 ++++++++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index 430381ba7e5e..7bdf16944df3 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -55,6 +55,7 @@ #define L2CAP_MOVE_TIMEOUT msecs_to_jiffies(4000) #define L2CAP_MOVE_ERTX_TIMEOUT msecs_to_jiffies(60000) #define L2CAP_WAIT_ACK_POLL_PERIOD msecs_to_jiffies(200) +#define L2CAP_WAIT_ACK_TIMEOUT msecs_to_jiffies(10000) #define L2CAP_A2MP_DEFAULT_MTU 670 diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 0bd277fba24e..00b43f008941 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1053,11 +1053,15 @@ static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) DECLARE_WAITQUEUE(wait, current); int err = 0; int timeo = L2CAP_WAIT_ACK_POLL_PERIOD; + /* Timeout to prevent infinite loop */ + unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT; add_wait_queue(sk_sleep(sk), &wait); set_current_state(TASK_INTERRUPTIBLE); do { - BT_DBG("Waiting for %d ACKs", chan->unacked_frames); + BT_DBG("Waiting for %d ACKs, timeout %04d ms", + chan->unacked_frames, time_after(jiffies, timeout) ? 0 : + jiffies_to_msecs(timeout - jiffies)); if (!timeo) timeo = L2CAP_WAIT_ACK_POLL_PERIOD; @@ -1076,6 +1080,11 @@ static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) if (err) break; + if (time_after(jiffies, timeout)) { + err = -ENOLINK; + break; + } + } while (chan->unacked_frames > 0 && chan->state == BT_CONNECTED); -- 2.17.1