On Thu, Nov 19, 2020 at 11:34:29AM +0300, Mika Westerberg wrote:
> Paulian reported a crash that happens when a dock is unplugged during
> hibernation:
>
> [78436.228217] thunderbolt 0-1: device disconnected
> [78436.228365] BUG: kernel NULL pointer dereference, address: 00000000000001e0
> ...
> [78436.228397] RIP: 0010:icm_free_unplugged_children+0x109/0x1a0
> ...
> [78436.228432] Call Trace:
> [78436.228439] icm_rescan_work+0x24/0x30
> [78436.228444] process_one_work+0x1a3/0x3a0
> [78436.228449] worker_thread+0x30/0x370
> [78436.228454] ? process_one_work+0x3a0/0x3a0
> [78436.228457] kthread+0x13d/0x160
> [78436.228461] ? kthread_park+0x90/0x90
> [78436.228465] ret_from_fork+0x1f/0x30
>
> This happens because remove_unplugged_switch() calls tb_switch_remove()
> that releases the memory pointed by sw so the following lines reference
> to a memory that might be released already.
>
> Fix this by saving pointer to the parent device before calling
> tb_switch_remove().
>
> Reported-by: Paulian Bogdan Marinca <paulian@xxxxxxxxxxx>
> Fixes: 4f7c2e0d8765 ("thunderbolt: Make sure device runtime resume completes before taking domain lock")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
