[PATCH] KVM: Prevent double-free on HPT resize commit path
paulus at ozlabs.org
Tue Feb 28 15:59:27 AEDT 2017
On Tue, Feb 28, 2017 at 11:56:55AM +1100, David Gibson wrote:
> On Wed, Feb 15, 2017 at 02:40:04PM +1100, David Gibson wrote:
> > resize_hpt_release(), called once the HPT resize of a KVM guest is
> > completed (successfully or unsuccessfully) free()s the state structure for
> > the resize. It is currently not safe to call with a NULL pointer.
> > However, one of the error paths in kvm_vm_ioctl_resize_hpt_commit() can
> > invoke it with a NULL pointer. This will occur if userspace improperly
> > invokes KVM_PPC_RESIZE_HPT_COMMIT without previously calling
> > KVM_PPC_RESIZE_HPT_PREPARE, or if it calls COMMIT twice without an
> > intervening PREPARE.
> > To fix this potential crash bug - and maybe others like it, make it safe
> > (and a no-op) to call resize_hpt_release() with a NULL resize pointer.
> > Found by Dan Carpenter with a static checker.
> > Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
> > Signed-off-by: David Gibson <david at gibson.dropbear.id.au>
> Paul have you taken this one?
Yes, thanks, it's in Linus' tree now.
More information about the Linuxppc-dev