[PATCH 4.4 11/43] xhci: xhci-mem: off by one in xhci_stream_id_to_ring()

From: Greg Kroah-Hartman
Date: Mon Jul 16 2018 - 03:44:06 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 313db3d6488bb03b61b99de9dbca061f1fd838e1 upstream.

The > should be >= here so that we don't read one element beyond the end
of the ep->stream_info->stream_rings[] array.

Fixes: e9df17eb1408 ("USB: xhci: Correct assumptions about number of rings per endpoint.")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/host/xhci-mem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -638,7 +638,7 @@ struct xhci_ring *xhci_stream_id_to_ring
if (!ep->stream_info)
return NULL;

- if (stream_id > ep->stream_info->num_streams)
+ if (stream_id >= ep->stream_info->num_streams)
return NULL;
return ep->stream_info->stream_rings[stream_id];
}