• Niranjana Vishwanathapura's avatar
    drm/xe: Fix memory use after free · 2988cf02
    Niranjana Vishwanathapura authored
    The wait_event_timeout() on g2h_fence.wq which is declared on
    stack can return before the wake_up() gets called, resulting in a
    stack out of bound access when wake_up() accesses the g2h_fene.wq.
    
    Do not declare g2h_fence related wait_queue_head_t on stack.
    
    Fixes the below KASAN BUG and associated kernel crashes.
    
    BUG: KASAN: stack-out-of-bounds in do_raw_spin_lock+0x6f/0x1e0
    Read of size 4 at addr ffff88826252f4ac by task kworker/u128:5/467
    
    CPU: 25 PID: 467 Comm: kworker/u128:5 Tainted: G  U 6.3.0-rc4-xe #1
    Workqueue: events_unbound g2h_worker_func [xe]
    Call Trace:
     <TASK>
     dump_stack_lvl+0x64/0xb0
     print_report+0xc2/0x600
     kasan_report+0x96/0xc0
     do_raw_spin_lock+0x6f/0x1e0
     _raw_spin_lock_irqsave+0x47/0x60
     __wake_up_common_lock+0xc0/0x150
     dequeue_one_g2h+0x20f/0x6a0 [xe]
     g2h_worker_func+0xa9/0x180 [xe]
     process_one_work+0x527/0x990
     worker_thread+0x2d1/0x640
     kthread+0x174/0x1b0
     ret_from_fork+0x29/0x50
     </TASK>
    Tested-by: default avatarMatt Roper <matthew.d.roper@intel.com>
    Reviewed-by: default avatarBruce Chang <yu.bruce.chang@intel.com>
    Signed-off-by: default avatarNiranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
    Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
    2988cf02
xe_guc_ct.c 30.2 KB