Re: [PATCH for_v23 3/9] x86/sgx: Fix a memory leak in sgx_encl_destroy()

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Tue, Oct 15, 2019 at 12:00:27AM +0300, Jarkko Sakkinen wrote:
> On Thu, Oct 10, 2019 at 03:49:48PM -0700, Sean Christopherson wrote:
> > On Thu, Oct 10, 2019 at 02:42:55PM -0700, Sean Christopherson wrote:
> > > Delete an enclave page's entry in the radix tree regardless of whether
> > > or not it has an associated EPC page.
> > > 
> > > Note, the reclaimer doesn't need the tree to reclaim EPC pages, i.e.
> > > it's safe to delete the tree entry even if sgx_free_page() fails.
> > > 
> > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> > > ---
> > >  arch/x86/kernel/cpu/sgx/encl.c | 15 +++++++--------
> > >  1 file changed, 7 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> > > index ea21d3737a32..68ec8944692a 100644
> > > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > > @@ -468,15 +468,14 @@ void sgx_encl_destroy(struct sgx_encl *encl)
> > >  
> > >  	radix_tree_for_each_slot(slot, &encl->page_tree, &iter, 0) {
> > >  		entry = *slot;
> > > -		if (entry->epc_page) {
> > > -			if (!sgx_free_page(entry->epc_page)) {
> > > -				encl->secs_child_cnt--;
> > > -				entry->epc_page = NULL;
> > > -			}
> > > -
> > > -			radix_tree_delete(&entry->encl->page_tree,
> > > -					  PFN_DOWN(entry->desc));
> > > +		if (entry->epc_page &&
> > > +		    !sgx_free_page(entry->epc_page)) {
> > > +			encl->secs_child_cnt--;
> > > +			entry->epc_page = NULL;
> > >  		}
> > > +
> > > +		radix_tree_delete(&entry->encl->page_tree,
> > > +				  PFN_DOWN(entry->desc));
> > 
> > Uh, just realized we're not freeing the entry itself.  That's obviously
> > not good.  I'll spin a v2 to fix this proper.
> 
> OK.
> 
> So I applied 1/9 and 2/9 from this one. I guess they were good
> (just a sanity check)?

Yep.