From: Mathias Nyman Date: Wed, 7 Sep 2016 14:26:33 +0000 (+0300) Subject: xhci: fix null pointer dereference in stop command timeout function X-Git-Tag: firefly_0821_release~176^2~4^2~28^2~51 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6267a54a24331b4ddee59ebf98c76e92cfed6719;p=firefly-linux-kernel-4.4.55.git xhci: fix null pointer dereference in stop command timeout function commit bcf42aa60c2832510b9be0f30c090bfd35bb172d upstream. The stop endpoint command has its own 5 second timeout timer. If the timeout function is triggered between USB3 and USB2 host removal it will try to call usb_hc_died(xhci_to_hcd(xhci)->primary_hcd) the ->primary_hcd will be set to NULL at USB3 hcd removal. Fix this by first checking if the PCI host is being removed, and also by using only xhci_to_hcd() as it will always return the primary hcd. Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 1f37b89e7267..62a5c8d5e028 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -846,6 +846,10 @@ void xhci_stop_endpoint_command_watchdog(unsigned long arg) spin_lock_irqsave(&xhci->lock, flags); ep->stop_cmds_pending--; + if (xhci->xhc_state & XHCI_STATE_REMOVING) { + spin_unlock_irqrestore(&xhci->lock, flags); + return; + } if (xhci->xhc_state & XHCI_STATE_DYING) { xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb, "Stop EP timer ran, but another timer marked " @@ -899,7 +903,7 @@ void xhci_stop_endpoint_command_watchdog(unsigned long arg) spin_unlock_irqrestore(&xhci->lock, flags); xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb, "Calling usb_hc_died()"); - usb_hc_died(xhci_to_hcd(xhci)->primary_hcd); + usb_hc_died(xhci_to_hcd(xhci)); xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb, "xHCI host controller is dead."); }