Merge branch 'linus' into core/softirq

2 files changed, 13 insertions, 2 deletions

diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index eb62558..0c2c937 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -423,8 +423,8 @@ static int __rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
 
 		rfcomm_dlc_lock(d);
 		d->state = BT_CLOSED;
-		rfcomm_dlc_unlock(d);
 		d->state_change(d, err);
+		rfcomm_dlc_unlock(d);
 
 		skb_queue_purge(&d->tx_queue);
 		rfcomm_dlc_unlink(d);
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index c3f749a..c919187 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -566,11 +566,22 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
 	if (dlc->state == BT_CLOSED) {
 		if (!dev->tty) {
 			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
-				if (rfcomm_dev_get(dev->id) == NULL)
+				/* Drop DLC lock here to avoid deadlock
+				 * 1. rfcomm_dev_get will take rfcomm_dev_lock
+				 *    but in rfcomm_dev_add there's lock order:
+				 *    rfcomm_dev_lock -> dlc lock
+				 * 2. rfcomm_dev_put will deadlock if it's
+				 *    the last reference
+				 */
+				rfcomm_dlc_unlock(dlc);
+				if (rfcomm_dev_get(dev->id) == NULL) {
+					rfcomm_dlc_lock(dlc);
 					return;
+				}
 
 				rfcomm_dev_del(dev);
 				rfcomm_dev_put(dev);
+				rfcomm_dlc_lock(dlc);
 			}
 		} else
 			tty_hangup(dev->tty);