diff options
| author | Michael Scott <michael.scott@linaro.org> | 2017-03-28 23:10:54 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-22 09:17:52 +0100 |
| commit | b7ac7e479ae38810bc06fb662fe6e7e1ac7df3cf (patch) | |
| tree | b19da51d08c2c34e2180f9d2eb0e7d789772655d /net | |
| parent | f3fa28a381b8a61cd2f3631936e6aa6c48363cb9 (diff) | |
Bluetooth: 6lowpan: fix delay work init in add_peer_chan()
[ Upstream commit d2891c4d071d807f01cc911dc42a68f4568d65cf ]
When adding 6lowpan devices very rapidly we sometimes see a crash:
[23122.306615] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.0-43-arm64 #1 Debian 4.9.9.linaro.43-1
[23122.315400] Hardware name: HiKey Development Board (DT)
[23122.320623] task: ffff800075443080 task.stack: ffff800075484000
[23122.326551] PC is at expire_timers+0x70/0x150
[23122.330907] LR is at run_timer_softirq+0xa0/0x1a0
[23122.335616] pc : [<ffff000008142dd8>] lr : [<ffff000008142f58>] pstate: 600001c5
This was due to add_peer_chan() unconditionally initializing the
lowpan_btle_dev->notify_peers delayed work structure, even if the
lowpan_btle_dev passed into add_peer_chan() had previously been
initialized.
Normally, this would go unnoticed as the delayed work timer is set for
100 msec, however when calling add_peer_chan() faster than 100 msec it
clears out a previously queued delay work causing the crash above.
To fix this, let add_peer_chan() know when a new lowpan_btle_dev is passed
in so that it only performs the delay work initialization when needed.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bluetooth/6lowpan.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index 1904a93f47d5..de7b82ece499 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -755,7 +755,8 @@ static void set_ip_addr_bits(u8 addr_type, u8 *addr) } static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, - struct lowpan_btle_dev *dev) + struct lowpan_btle_dev *dev, + bool new_netdev) { struct lowpan_peer *peer; @@ -786,7 +787,8 @@ static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, spin_unlock(&devices_lock); /* Notifying peers about us needs to be done without locks held */ - INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); + if (new_netdev) + INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); return peer->chan; @@ -843,6 +845,7 @@ out: static inline void chan_ready_cb(struct l2cap_chan *chan) { struct lowpan_btle_dev *dev; + bool new_netdev = false; dev = lookup_dev(chan->conn); @@ -853,12 +856,13 @@ static inline void chan_ready_cb(struct l2cap_chan *chan) l2cap_chan_del(chan, -ENOENT); return; } + new_netdev = true; } if (!try_module_get(THIS_MODULE)) return; - add_peer_chan(chan, dev); + add_peer_chan(chan, dev, new_netdev); ifup(dev->netdev); } |