| Message ID | 20200320205546.2396-7-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Fix memslot use-after-free bug | expand |
On Fri, Mar 20, 2020 at 01:55:45PM -0700, Sean Christopherson wrote: > Add a define for the primary memslot number so that tests can manipulate > the memslot, e.g. to delete it. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > tools/testing/selftests/kvm/include/kvm_util.h | 2 ++ > tools/testing/selftests/kvm/lib/kvm_util.c | 4 ++-- > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h > index 0f0e86e188c4..43b5feb546c6 100644 > --- a/tools/testing/selftests/kvm/include/kvm_util.h > +++ b/tools/testing/selftests/kvm/include/kvm_util.h > @@ -60,6 +60,8 @@ enum vm_mem_backing_src_type { > VM_MEM_SRC_ANONYMOUS_HUGETLB, > }; > > +#define VM_PRIMARY_MEM_SLOT 0 > + > int kvm_check_cap(long cap); > int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap); > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > index f69fa84c9a4c..6a1af0455e44 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -247,8 +247,8 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) > /* Allocate and setup memory for guest. */ > vm->vpages_mapped = sparsebit_alloc(); > if (phy_pages != 0) > - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, > - 0, 0, phy_pages, 0); > + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, > + VM_PRIMARY_MEM_SLOT, phy_pages, 0); IIUC VM_PRIMARY_MEM_SLOT should be used more than here... E.g., to all the places that allocate page tables in virt_map() as the last param? I didn't check other places. Maybe it's simpler to drop this patch for now and use 0 directly as before for now, after all in the last patch the comment is good enough for me to understand slot 0 is the default slot. Thanks, > > return vm; > } > -- > 2.24.1 >
On Mon, Mar 23, 2020 at 03:12:02PM -0400, Peter Xu wrote: > On Fri, Mar 20, 2020 at 01:55:45PM -0700, Sean Christopherson wrote: > > Add a define for the primary memslot number so that tests can manipulate > > the memslot, e.g. to delete it. > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > > --- > > tools/testing/selftests/kvm/include/kvm_util.h | 2 ++ > > tools/testing/selftests/kvm/lib/kvm_util.c | 4 ++-- > > 2 files changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h > > index 0f0e86e188c4..43b5feb546c6 100644 > > --- a/tools/testing/selftests/kvm/include/kvm_util.h > > +++ b/tools/testing/selftests/kvm/include/kvm_util.h > > @@ -60,6 +60,8 @@ enum vm_mem_backing_src_type { > > VM_MEM_SRC_ANONYMOUS_HUGETLB, > > }; > > > > +#define VM_PRIMARY_MEM_SLOT 0 > > + > > int kvm_check_cap(long cap); > > int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap); > > > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > > index f69fa84c9a4c..6a1af0455e44 100644 > > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > > @@ -247,8 +247,8 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) > > /* Allocate and setup memory for guest. */ > > vm->vpages_mapped = sparsebit_alloc(); > > if (phy_pages != 0) > > - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, > > - 0, 0, phy_pages, 0); > > + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, > > + VM_PRIMARY_MEM_SLOT, phy_pages, 0); > > IIUC VM_PRIMARY_MEM_SLOT should be used more than here... E.g., to all > the places that allocate page tables in virt_map() as the last param? > I didn't check other places. Ouch, yeah, it bleeds into vm_vaddr_alloc() as well. > Maybe it's simpler to drop this patch for now and use 0 directly as > before for now, after all in the last patch the comment is good enough > for me to understand slot 0 is the default slot. Ya, I'll drop this and hardcode '0', it's a rather absurd amount of call sites to change.
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 0f0e86e188c4..43b5feb546c6 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -60,6 +60,8 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS_HUGETLB, }; +#define VM_PRIMARY_MEM_SLOT 0 + int kvm_check_cap(long cap); int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap); diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index f69fa84c9a4c..6a1af0455e44 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -247,8 +247,8 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) /* Allocate and setup memory for guest. */ vm->vpages_mapped = sparsebit_alloc(); if (phy_pages != 0) - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, - 0, 0, phy_pages, 0); + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, + VM_PRIMARY_MEM_SLOT, phy_pages, 0); return vm; }
Add a define for the primary memslot number so that tests can manipulate the memslot, e.g. to delete it. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- tools/testing/selftests/kvm/include/kvm_util.h | 2 ++ tools/testing/selftests/kvm/lib/kvm_util.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-)