We naively assume that the IRQ value passed in is correct. If it is not, then any dereference operation for the 'info' structure will result in crash - so might as well guard ourselves and sprinkle copious amounts of WARN_ON.
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> --- drivers/xen/events.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index bb65f75..94daed1 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -515,6 +515,9 @@ static void xen_free_irq(unsigned irq) { struct irq_info *info = irq_get_handler_data(irq); + if (WARN_ON(!info)) + return; + list_del(&info->list); irq_set_handler_data(irq, NULL); @@ -1003,6 +1006,9 @@ static void unbind_from_irq(unsigned int irq) int evtchn = evtchn_from_irq(irq); struct irq_info *info = irq_get_handler_data(irq); + if (WARN_ON(!info)) + return; + mutex_lock(&irq_mapping_update_lock); if (info->refcnt > 0) { @@ -1130,6 +1136,10 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi, void unbind_from_irqhandler(unsigned int irq, void *dev_id) { + struct irq_info *info = irq_get_handler_data(irq); + + if (WARN_ON(!info)) + return; free_irq(irq, dev_id); unbind_from_irq(irq); } @@ -1441,6 +1451,9 @@ void rebind_evtchn_irq(int evtchn, int irq) { struct irq_info *info = info_for_irq(irq); + if (WARN_ON(!info)) + return; + /* Make sure the irq is masked, since the new event channel will also be masked. */ disable_irq(irq); @@ -1714,7 +1727,12 @@ void xen_poll_irq(int irq) int xen_test_irq_shared(int irq) { struct irq_info *info = info_for_irq(irq); - struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq }; + struct physdev_irq_status_query irq_status; + + if (WARN_ON(!info)) + return -ENOENT; + + irq_status.irq = info->u.pirq.pirq; if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status)) return 0; -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
