From: Luiz Augusto von Dentz luiz.von.dentz@intel.com
commit a2a9339e1c9deb7e1e079e12e27a0265aea8421a upstream.
Similar to commit d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put"), just use l2cap_chan_hold_unless_zero to prevent referencing a channel that is about to be destroyed.
Cc: stable@kernel.org Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Min Li lm0963hack@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/bluetooth/l2cap_core.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-)
--- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4368,33 +4368,27 @@ static inline int l2cap_disconnect_req(s
BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
- mutex_lock(&conn->chan_lock); - - chan = __l2cap_get_chan_by_scid(conn, dcid); + chan = l2cap_get_chan_by_scid(conn, dcid); if (!chan) { - mutex_unlock(&conn->chan_lock); cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid); return 0; }
- l2cap_chan_hold(chan); - l2cap_chan_lock(chan); - rsp.dcid = cpu_to_le16(chan->scid); rsp.scid = cpu_to_le16(chan->dcid); l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
chan->ops->set_shutdown(chan);
+ mutex_lock(&conn->chan_lock); l2cap_chan_del(chan, ECONNRESET); + mutex_unlock(&conn->chan_lock);
chan->ops->close(chan);
l2cap_chan_unlock(chan); l2cap_chan_put(chan);
- mutex_unlock(&conn->chan_lock); - return 0; }
@@ -4414,33 +4408,27 @@ static inline int l2cap_disconnect_rsp(s
BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
- mutex_lock(&conn->chan_lock); - - chan = __l2cap_get_chan_by_scid(conn, scid); + chan = l2cap_get_chan_by_scid(conn, scid); if (!chan) { mutex_unlock(&conn->chan_lock); return 0; }
- l2cap_chan_hold(chan); - l2cap_chan_lock(chan); - if (chan->state != BT_DISCONN) { l2cap_chan_unlock(chan); l2cap_chan_put(chan); - mutex_unlock(&conn->chan_lock); return 0; }
+ mutex_lock(&conn->chan_lock); l2cap_chan_del(chan, 0); + mutex_unlock(&conn->chan_lock);
chan->ops->close(chan);
l2cap_chan_unlock(chan); l2cap_chan_put(chan);
- mutex_unlock(&conn->chan_lock); - return 0; }