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xhci: fix null pointer dereference in stop command timeout function 

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.

CC: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2016-09-07 17:26:33 +03:00 committed by Greg Kroah-Hartman
parent c6935931c1
commit bcf42aa60c
1 changed files with 5 additions and 1 deletions
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6
drivers/usb/host/xhci-ring.c
View File

@ -850,6 +850,10 @@ 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 "
@ -903,7 +907,7 @@ 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.");
}