xhci: fix bounce buffer usage for non-sg list case
commit d4a61063 upstream. xhci driver may in some special cases need to copy small amounts of payload data to a bounce buffer in order to meet the boundary and alignment restrictions set by the xHCI specification. In the majority of these cases the data is in a sg list, and driver incorrectly assumed data is always in urb->sg when using the bounce buffer. If data instead is contiguous, and in urb->transfer_buffer, we may still need to bounce buffer a small part if data starts very close (less than packet size) to a 64k boundary. Check if sg list is used before copying data to/from it. Fixes: f9c589e1 ("xhci: TD-fragment, align the unsplittable case with a bounce buffer") Cc: stable@vger.kernel.org Reported-by:Andreas Hartmann <andihartmann@01019freenet.de> Tested-by:
Andreas Hartmann <andihartmann@01019freenet.de> Signed-off-by:
Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210203113702.436762-2-mathias.nyman@linux.intel.com Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ee23b932
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