tquaf: queue 0xfffff8011756aec8 started (0)
tquaf: taskqueue_cancel(t1) = 0 while t1 running (0 = contract violated, EBUSY=16 expected)
tquaf: BUG PROVEN: taskqueue_drain(t1) returned while t1 ta_func still executing
tquaf: freeing live task context 0xfffff8008d2e0810
tquaf: freed ctx reallocated at 0xfffff8008d2e0810 (alias YES) magic=deadbeef
tquaf: UAF CONFIRMED: running task sees ctx 0xfffff8008d2e0810 magic=deadbeef (expected cafebabe)
panic: DF-2869: task context freed while task running (magic=deadbeef)
cpuid = 0
Trace beginning at frame 0xfffff8011867fa00
t1_func() at t1_func+0x9b 0xffffffff826010ab 
t1_func() at t1_func+0x9b 0xffffffff826010ab 
taskqueue_run() at taskqueue_run+0xbb 0xffffffff806a3c5b 
taskqueue_thread_loop() at taskqueue_thread_loop+0x5d 0xffffffff806a3e1d 
Debugger("panic")

CPU0 stopping CPUs: 0x0000003e
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
db>