Messages in this thread Patch in this message | | | Date | Tue, 27 Feb 2018 16:58:10 +0000 | From | Roger Pau Monné <> | Subject | Re: [PATCH v2 1/2] xen: fix out-of-bounds irq unbind for MSI message groups |
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On Tue, Feb 27, 2018 at 03:55:57PM +0000, Amit Shah wrote: > When an MSI descriptor was not available, the error path would try to > unbind an irq that was never acquired - potentially unbinding an > unrelated irq.
Those IRQs have been allocated in the xen_allocate_irqs_dynamic call, so I think the "potentially unbinding an unrelated irq" part is wrong. The unbind call would be performed against an unbound IRQ, which is harmless AFAICT.
> Fixes: 4892c9b4ada9f9 ("xen: add support for MSI message groups") > Reported-by: Hooman Mirhadi <mirhadih@amazon.com> > CC: <stable@vger.kernel.org> > CC: Roger Pau Monné <roger.pau@citrix.com> > CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> > CC: Eduardo Valentin <eduval@amazon.com> > CC: Juergen Gross <jgross@suse.com> > CC: Thomas Gleixner <tglx@linutronix.de> > CC: "K. Y. Srinivasan" <kys@microsoft.com> > CC: Liu Shuo <shuo.a.liu@intel.com> > CC: Anoob Soman <anoob.soman@citrix.com> > Signed-off-by: Amit Shah <aams@amazon.com> > --- > drivers/xen/events/events_base.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c > index 1ab4bd1..c86d10e 100644 > --- a/drivers/xen/events/events_base.c > +++ b/drivers/xen/events/events_base.c > @@ -755,8 +755,10 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, > mutex_unlock(&irq_mapping_update_lock); > return irq; > error_irq: > - for (; i >= 0; i--) > + while (i > 0) {
while (i--) __unbind_from_irq(irq + i);
Although please see reply to patch 2.
Roger.
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