xhci: Fix NULL pointer dereference when cleaning up streams for removed host

This off by one in stream_id indexing caused NULL pointer dereference and
soft lockup on machines with USB attached SCSI devices connected to a
hotpluggable xhci controller.

The code that cleans up pending URBs for dead hosts tried to dereference
a stream ring at the invalid stream_id 0.
ep->stream_info->stream_rings[0] doesn't point to a ring.

Start looping stream_id from 1 like in all the other places in the driver,
and check that the ring exists before trying to kill URBs on it.

Reported-by: rocko r <rockorequin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2017-07-20 14:48:26 +03:00 committed by Greg Kroah-Hartman
parent 3d69f3a8c2
commit 4b895868bb
1 changed files with 7 additions and 4 deletions

View File

@ -864,13 +864,16 @@ static void xhci_kill_endpoint_urbs(struct xhci_hcd *xhci,
(ep->ep_state & EP_GETTING_NO_STREAMS)) {
int stream_id;
for (stream_id = 0; stream_id < ep->stream_info->num_streams;
for (stream_id = 1; stream_id < ep->stream_info->num_streams;
stream_id++) {
ring = ep->stream_info->stream_rings[stream_id];
if (!ring)
continue;
xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
"Killing URBs for slot ID %u, ep index %u, stream %u",
slot_id, ep_index, stream_id + 1);
xhci_kill_ring_urbs(xhci,
ep->stream_info->stream_rings[stream_id]);
slot_id, ep_index, stream_id);
xhci_kill_ring_urbs(xhci, ring);
}
} else {
ring = ep->ring;