xhci: Check link TRBs when updating ring enqueue and dequeue pointers.

xhci driver relies on link TRBs existing in the correct places in TRB
ring buffers shared with the host controller.
The controller should not modify these link TRBs, but in theory a faulty
xHC could do it.

Add some basic sanity checks to avoid infinite loops in interrupt handler,
or accessing unallocated memory outside a ring segment due to missing or
misplaced link TRBs.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-14-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2021-01-29 15:00:30 +02:00 • committed by Greg Kroah-Hartman
commit c716e8a5fa