xhci: fix segfault

Guest trying to reset a endpoint of a disconnected device resulted in
xhci trying to dereference uport while being NULL, thereby crashing
qemu.  Fix that by adding a check.  Drop unused dev variable while
touching that code bit.

Cc: qemu-stable@nongnu.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 75cc1c1fcb)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This commit is contained in:
Gerd Hoffmann 2013-07-31 10:54:11 +02:00 committed by Michael Roth
parent a3ea885abd
commit 283d8f93e5
1 changed files with 2 additions and 3 deletions

View File

@ -1395,7 +1395,6 @@ static TRBCCode xhci_reset_ep(XHCIState *xhci, unsigned int slotid,
{
XHCISlot *slot;
XHCIEPContext *epctx;
USBDevice *dev;
trace_usb_xhci_ep_reset(slotid, epid);
assert(slotid >= 1 && slotid <= xhci->numslots);
@ -1431,8 +1430,8 @@ static TRBCCode xhci_reset_ep(XHCIState *xhci, unsigned int slotid,
ep |= 0x80;
}
dev = xhci->slots[slotid-1].uport->dev;
if (!dev) {
if (!xhci->slots[slotid-1].uport ||
!xhci->slots[slotid-1].uport->dev) {
return CC_USB_TRANSACTION_ERROR;
}