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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
        "Dan Carpenter" <dan.carpenter@oracle.com>
Date:   Sun, 11 Nov 2018 19:49:05 +0000
Message-ID: <lsq.1541965745.323089759@decadent.org.uk>
Subject: [PATCH 3.16 237/366] xhci: xhci-mem: off by one in
 xhci_stream_id_to_ring()
In-Reply-To: <lsq.1541965744.387173642@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
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3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Dan Carpenter <dan.carpenter@oracle.com>

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@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 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];
 }