File CVE-2015-8558-qemuu-usb-infinite-loop-in-ehci_a... of Package xen

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File CVE-2015-8558-qemuu-usb-infinite-loop-in-ehci_advance_state-results-in-DoS.patch of Package xen (Revision 9875da17792a203c93f49913fa35874a)

Currently displaying revision 9875da17792a203c93f49913fa35874a , Show latest

References: bsc#959006 CVE-2015-8558

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.

Reported-by: Qinghao Tang <address@hidden>
Tested-by: P J P <address@hidden>
Signed-off-by: Gerd Hoffmann <address@hidden>
---
 hw/usb/hcd-ehci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: xen-4.6.0-testing/tools/qemu-xen-dir-remote/hw/usb/hcd-ehci.c
===================================================================
--- xen-4.6.0-testing.orig/tools/qemu-xen-dir-remote/hw/usb/hcd-ehci.c
+++ xen-4.6.0-testing/tools/qemu-xen-dir-remote/hw/usb/hcd-ehci.c
@@ -1395,7 +1395,7 @@ static int ehci_process_itd(EHCIState *e
 {
     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;
@@ -1485,9 +1485,10 @@ static int ehci_process_itd(EHCIState *e
                 ehci_raise_irq(ehci, USBSTS_INT);
             }
             itd->transact[i] &= ~ITD_XACT_ACTIVE;
+            xfers++;
         }
     }
-    return 0;
+    return xfers ? 0 : -1;
 }

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File CVE-2015-8558-qemuu-usb-infinite-loop-in-ehci_advance_state-results-in-DoS.patch of Package xen (Revision 9875da17792a203c93f49913fa35874a)

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