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author | Matthias Kaehlcke <mka@chromium.org> | 2019-01-02 16:11:20 -0800 |
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committer | Marcel Holtmann <marcel@holtmann.org> | 2019-01-22 09:51:20 +0100 |
commit | c4f5627f7eeecde1bb6b646d8c0907b96dc2b2a6 (patch) | |
tree | 3caa470f040d4ce977c331a8367f2f70db561c79 /net/bluetooth/l2cap_sock.c | |
parent | 8c57983bf7a7987f957830614b1645bd6943f5af (diff) | |
download | linux-c4f5627f7eeecde1bb6b646d8c0907b96dc2b2a6.tar.gz |
Bluetooth: Fix locking in bt_accept_enqueue() for BH context
With commit e16337622016 ("Bluetooth: Handle bt_accept_enqueue() socket atomically") lock_sock[_nested]() is used to acquire the socket lock before manipulating the socket. lock_sock[_nested]() may block, which is problematic since bt_accept_enqueue() can be called in bottom half context (e.g. from rfcomm_connect_ind()): [<ffffff80080d81ec>] __might_sleep+0x4c/0x80 [<ffffff800876c7b0>] lock_sock_nested+0x24/0x58 [<ffffff8000d7c27c>] bt_accept_enqueue+0x48/0xd4 [bluetooth] [<ffffff8000e67d8c>] rfcomm_connect_ind+0x190/0x218 [rfcomm] Add a parameter to bt_accept_enqueue() to indicate whether the function is called from BH context, and acquire the socket lock with bh_lock_sock_nested() if that's the case. Also adapt all callers of bt_accept_enqueue() to pass the new parameter: - l2cap_sock_new_connection_cb() - uses lock_sock() to lock the parent socket => process context - rfcomm_connect_ind() - acquires the parent socket lock with bh_lock_sock() => BH context - __sco_chan_add() - called from sco_chan_add(), which is called from sco_connect(). parent is NULL, hence bt_accept_enqueue() isn't called in this code path and we can ignore it - also called from sco_conn_ready(). uses bh_lock_sock() to acquire the parent lock => BH context Fixes: e16337622016 ("Bluetooth: Handle bt_accept_enqueue() socket atomically") Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Cc: stable@vger.kernel.org
Diffstat (limited to 'net/bluetooth/l2cap_sock.c')
-rw-r--r-- | net/bluetooth/l2cap_sock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 686bdc6b35b0..a3a2cd55e23a 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1252,7 +1252,7 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) l2cap_sock_init(sk, parent); - bt_accept_enqueue(parent, sk); + bt_accept_enqueue(parent, sk, false); release_sock(parent); |