diff options
| author | Mat Martineau <mathewm@codeaurora.org> | 2012-05-02 09:42:00 -0700 |
|---|---|---|
| committer | Gustavo Padovan <gustavo.padovan@collabora.co.uk> | 2012-05-16 16:13:51 -0300 |
| commit | ef191aded58c5e6860b01f463818584a420a4d6b (patch) | |
| tree | 3459b8a02ec5b4ef4566f139275c1c9dc234b3ce | |
| parent | 35c84d76ee52f49fe2635d8cd686b5b658e8d892 (diff) | |
Bluetooth: Restore locking semantics when looking up L2CAP channels
As the comment for l2cap_get_chan_by_scid indicated, the function used
to return a locked socket. The lock for the socket was acquired while
the channel list was also locked.
When locking was moved over to the l2cap_chan structure, the channel
lock was no longer acquired with the channel list still locked. This
made it possible for the l2cap_chan to be deleted after
conn->chan_lock was released but before l2cap_chan_lock was called.
Making the call to l2cap_chan_lock before releasing conn->chan_lock
makes it impossible for the l2cap_chan to be deleted at the wrong
time.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Reviewed-by: Ulisses Furquim <ulisses@profusion.mobi>
Signed-off-by: Gustavo Padovan <gustavo@padovan.org>
| -rw-r--r-- | net/bluetooth/l2cap_core.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index aea54f55c41d..285c5e13c7d5 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -98,13 +98,15 @@ static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 } /* Find channel with given SCID. - * Returns locked socket */ + * Returns locked channel. */ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 cid) { struct l2cap_chan *c; mutex_lock(&conn->chan_lock); c = __l2cap_get_chan_by_scid(conn, cid); + if (c) + l2cap_chan_lock(c); mutex_unlock(&conn->chan_lock); return c; @@ -3183,8 +3185,6 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr if (!chan) return -ENOENT; - l2cap_chan_lock(chan); - if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) { struct l2cap_cmd_rej_cid rej; @@ -3297,8 +3297,6 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr if (!chan) return 0; - l2cap_chan_lock(chan); - switch (result) { case L2CAP_CONF_SUCCESS: l2cap_conf_rfc_get(chan, rsp->data, len); @@ -4631,8 +4629,6 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk return 0; } - l2cap_chan_lock(chan); - BT_DBG("chan %p, len %d", chan, skb->len); if (chan->state != BT_CONNECTED) |