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

Bluetooth: L2CAP: Fix user-after-free

This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace:

Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08

BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389