In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: Add missing chan lock in l2cap_ecred_reconf_rsp l2ca

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

Bluetooth: l2cap: Add missing chan lock in l2cap_ecred_reconf_rsp

l2cap_ecred_reconf_rsp() calls l2cap_chan_del() without holding
l2cap_chan_lock(). Every other l2cap_chan_del() caller in the file
acquires the lock first. A remote BLE device can send a crafted
L2CAP ECRED reconfiguration response to corrupt the channel list
while another thread is iterating it.

Add l2cap_chan_hold() and l2cap_chan_lock() before l2cap_chan_del(),
and l2cap_chan_unlock() and l2cap_chan_put() after, matching the
pattern used in l2cap_ecred_conn_rsp() and l2cap_conn_del().