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| author | Dean Jenkins <Dean_Jenkins@mentor.com> | 2015-06-23 19:59:39 +0300 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2015-07-23 18:10:51 +0300 |
| commit | e432c72c464d2deb6c66d1e2a5f548dc1f0ef4dc (patch) | |
| tree | 1206dfbdbb74bf9b5ffa8bf9999b824761cea681 | |
| parent | cb02a25583b59ce48267472cd092485d754964f9 (diff) | |
| download | linux-e432c72c464d2deb6c66d1e2a5f548dc1f0ef4dc.tar.xz | |
Bluetooth: __l2cap_wait_ack() add defensive timeout
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@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
| -rw-r--r-- | include/net/bluetooth/l2cap.h | 1 | ||||
| -rw-r--r-- | net/bluetooth/l2cap_sock.c | 11 |
2 files changed, 11 insertions, 1 deletions
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index 3dcad4159b0b..c98afc08cc26 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -56,6 +56,7 @@ #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 f0b052a75e8a..586b3d580cfc 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1059,11 +1059,15 @@ 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; @@ -1082,6 +1086,11 @@ 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); |