Re: [PATCH] KVM: remove printing of token address

From: Paolo Bonzini
Date: Mon Oct 09 2017 - 03:49:57 EST




----- Original Message -----
> From: "Tobin C. Harding" <me@xxxxxxxx>
> To: "Paolo Bonzini" <pbonzini@xxxxxxxxxx>, rkrcmar@xxxxxxxxxx
> Cc: kvm@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, "Tobin C. Harding" <me@xxxxxxxx>
> Sent: Monday, October 9, 2017 8:30:14 AM
> Subject: [PATCH] KVM: remove printing of token address
>
> KVM currently prints the address of the consumer token. It is not
> immediately clear what benefit it is to see this address. Printing
> this address leaks kernel pointers into dmesg and is a security risk.
>
> Remove the consumer token address from error message output.

It should use %pK instead. Also, please do the same change on the VFIO
side (drivers/vfio/pci/vfio_pci_intrs.c, call to irq_bypass_register_producer).

Thanks,

Paolo

>
> Signed-off-by: Tobin C. Harding <me@xxxxxxxx>
> ---
> virt/kvm/eventfd.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index f2ac53ab8243..b54503ed60bd 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -416,8 +416,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
> irqfd->consumer.start = kvm_arch_irq_bypass_start;
> ret = irq_bypass_register_consumer(&irqfd->consumer);
> if (ret)
> - pr_info("irq bypass consumer (token %p) registration fails: %d\n",
> - irqfd->consumer.token, ret);
> + pr_info("irq bypass consumer registration fails: %d\n", ret);
> }
> #endif
>
> --
> 2.7.4
>
>