On 22/08/2017 03:07, nixiaoming wrote:
> The error parameter passed through the external interface
> causes the system oops. So it is necessary to increase the
> parameter check for all EXPORT_SYMBOL_GPL
>
> example:
> int irq_bypass_register_producer(struct irq_bypass_producer *producer)
> {
> if (!producer->token) /* oops if producer == null */
> return -einval;
> }
> EXPORT_SYMBOL_GPL(irq_bypass_register_producer);
This is used like this:
drivers/vfio/pci/vfio_pci_intrs.c: irq_bypass_unregister_producer(&vdev->ctx[vector].producer);
drivers/vfio/pci/vfio_pci_intrs.c: ret = irq_bypass_register_producer(&vdev->ctx[vector].producer);
virt/kvm/eventfd.c: irq_bypass_unregister_consumer(&irqfd->consumer);
virt/kvm/eventfd.c: ret = irq_bypass_register_consumer(&irqfd->consumer);
So your check won't actually catch irqfd or vdev being NULL.
Paolo
> Signed-off-by: nixiaoming <nixiaoming@xxxxxxxxxx>
> ---
> virt/lib/irqbypass.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/virt/lib/irqbypass.c b/virt/lib/irqbypass.c
> index 6d2fcd6..2bb99e8 100644
> --- a/virt/lib/irqbypass.c
> +++ b/virt/lib/irqbypass.c
> @@ -89,7 +89,7 @@ int irq_bypass_register_producer(struct irq_bypass_producer *producer)
> struct irq_bypass_producer *tmp;
> struct irq_bypass_consumer *consumer;
>
> - if (!producer->token)
> + if (!producer || !producer->token)
> return -EINVAL;
>
> might_sleep();
> @@ -139,7 +139,7 @@ void irq_bypass_unregister_producer(struct irq_bypass_producer *producer)
> struct irq_bypass_producer *tmp;
> struct irq_bypass_consumer *consumer;
>
> - if (!producer->token)
> + if (!producer || !producer->token)
> return;
>
> might_sleep();
> @@ -183,7 +183,7 @@ int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer)
> struct irq_bypass_consumer *tmp;
> struct irq_bypass_producer *producer;
>
> - if (!consumer->token ||
> + if (!consumer || !consumer->token ||
> !consumer->add_producer || !consumer->del_producer)
> return -EINVAL;
>
> @@ -234,7 +234,7 @@ void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer)
> struct irq_bypass_consumer *tmp;
> struct irq_bypass_producer *producer;
>
> - if (!consumer->token)
> + if (!consumer || !consumer->token)
> return;
>
> might_sleep();
>
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