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qemu-patch-raspberry4
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ehci: make idt processing more robust 

Make ehci_process_itd return an error in case we didn't do any actual
iso transfer because we've found no active transaction.  That'll avoid
ehci happily run in circles forever if the guest builds a loop out of
idts.

This is CVE-2015-8558.

Cc: qemu-stable@nongnu.org
Reported-by: Qinghao Tang <luodalongde@gmail.com>
Tested-by: P J P <ppandit@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 156a2e4dbf)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
stable-2.5
Gerd Hoffmann 2015-12-14 09:21:23 +01:00 committed by Michael Roth
parent a8c40fa2d6
commit 0d335804e3
1 changed files with 3 additions and 2 deletions
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5
hw/usb/hcd-ehci.c
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@ -1389,7 +1389,7 @@ static int ehci_process_itd(EHCIState *ehci,
{
USBDevice *dev;
USBEndpoint *ep;
uint32_t i, len, pid, dir, devaddr, endp;
uint32_t i, len, pid, dir, devaddr, endp, xfers = 0;
uint32_t pg, off, ptr1, ptr2, max, mult;
ehci->periodic_sched_active = PERIODIC_ACTIVE;
@ -1479,9 +1479,10 @@ static int ehci_process_itd(EHCIState *ehci,
ehci_raise_irq(ehci, USBSTS_INT);
}
itd->transact[i] &= ~ITD_XACT_ACTIVE;
xfers++;
}
}
return 0;
return xfers ? 0 : -1;
}