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authorMathias Nyman <mathias.nyman@linux.intel.com>2017-07-20 14:48:26 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-20 14:40:35 +0200
commit4b895868bb2da60a386a17cde3bf9ecbc70c79f4 (patch)
treeb2cda155a97ff5e0e0cbc20889775cb03249e3f8
parent3d69f3a8c2ed1c7f322d23145bc0c3d980ebbacb (diff)
downloadlinux-4b895868bb2da60a386a17cde3bf9ecbc70c79f4.tar.bz2
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>
-rw-r--r--drivers/usb/host/xhci-ring.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index c50c902d009e..cc368ad2b51e 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -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;