Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 06/23] xhci: fix null pointer dereference on ring_doorbell_for_active_rings | Date | Fri, 2 Aug 2013 18:23:19 +0800 |
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3.0-stable review patch. If anyone has any objections, please let me know.
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From: Oleksij Rempel <linux@rempel-privat.de>
commit d66eaf9f89502971fddcb0de550b01fa6f409d83 upstream.
in some cases where device is attched to xhci port and do not responding, for example ath9k_htc with stalled firmware, kernel will crash on ring_doorbell_for_active_rings. This patch check if pointer exist before it is used.
This patch should be backported to kernels as old as 2.6.35, that contain the commit e9df17eb1408cfafa3d1844bfc7f22c7237b31b8 "USB: xhci: Correct assumptions about number of rings per endpoint"
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/host/xhci-ring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -465,7 +465,7 @@ static void ring_doorbell_for_active_rin /* A ring has pending URBs if its TD list is not empty */ if (!(ep->ep_state & EP_HAS_STREAMS)) { - if (!(list_empty(&ep->ring->td_list))) + if (ep->ring && !(list_empty(&ep->ring->td_list))) xhci_ring_ep_doorbell(xhci, slot_id, ep_index, 0); return; }
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