CVE-2026-63948

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn

__set_chan_timer() takes a l2cap_chan reference via l2cap_chan_hold()
before scheduling the delayed work.  The normal path in
l2cap_chan_timeout() drops this reference with l2cap_chan_put() at the
end, but the early return when chan->conn is NULL skips the put,
leaking the reference.

Add the missing l2cap_chan_put() before the early return.