On Fri, Nov 30, 2018 at 09:37:49AM +0100, Markus Armbruster wrote:
> Eduardo Habkost <ehabk...@redhat.com> writes:
>
> > host_memory_backend_set_host_nodes() was not validating
> > host-nodes before writing to backend->host_nodes, making QEMU
> > write beyond the end of the bitmap.
> >
> > Fix the crash and add a simple regression test for the fix.
> >
> > Reported-by: Markus Armbruster <arm...@redhat.com>
> > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> > ---
> > backends/hostmem.c | 13 +++++++---
> > tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
> > 2 files changed, 46 insertions(+), 3 deletions(-)
> > create mode 100644 tests/acceptance/host-nodes-limit.py
> >
> > diff --git a/backends/hostmem.c b/backends/hostmem.c
> > index 1a89342039..ef199d32fd 100644
> > --- a/backends/hostmem.c
> > +++ b/backends/hostmem.c
> > @@ -103,11 +103,18 @@ host_memory_backend_set_host_nodes(Object *obj,
> > Visitor *v, const char *name,
> > {
> > #ifdef CONFIG_NUMA
> > HostMemoryBackend *backend = MEMORY_BACKEND(obj);
> > - uint16List *l = NULL;
> > + uint16List *l, *host_nodes = NULL;
> >
> > - visit_type_uint16List(v, name, &l, errp);
> > + visit_type_uint16List(v, name, &host_nodes, errp);
> > +
> > + for (l = host_nodes; l; l = l->next) {
> > + if (l->value >= MAX_NODES) {
> > + error_setg(errp, "Invalid host-nodes value: %d", l->value);
> > + return;
> > + }
> > + }
> >
> > - while (l) {
> > + for (l = host_nodes; l; l = l->next) {
> > bitmap_set(backend->host_nodes, l->value, 1);
> > l = l->next;
> > }
>
> Pre-existing: leaks the list created by visit_type_uint16List(), or am I
> confused?
>
> host_memory_backend_set_host_nodes() looks like it leaks, too.
>
> The function to free such lists is qapi_free_uint16List().
Thanks, I will fix it in v2.
>
> > diff --git a/tests/acceptance/host-nodes-limit.py
> > b/tests/acceptance/host-nodes-limit.py
> > new file mode 100644
> > index 0000000000..e803e10104
> > --- /dev/null
> > +++ b/tests/acceptance/host-nodes-limit.py
> > @@ -0,0 +1,36 @@
> > +# Regression test for host-nodes limit validation
> > +#
> > +# Copyright (c) 2018 Red Hat, Inc.
> > +#
> > +# Author:
> > +# Eduardo Habkost <ehabk...@redhat.com>
> > +#
> > +# This work is licensed under the terms of the GNU GPL, version 2 or
> > +# later. See the COPYING file in the top-level directory.
> > +
> > +from avocado_qemu import Test
> > +from subprocess import Popen, PIPE
> > +
> > +MAX_NODES = 128
> > +
> > +class HostNodesValidation(Test):
> > + def test_large_host_nodes(self):
> > + p = Popen([self.qemu_bin, '-display', 'none', '-nodefaults',
> > + '-object', 'memory-backend-ram,id=m0,'
> > + 'size=4096,host-nodes=%d' % (MAX_NODES)],
> > + stderr=PIPE, stdout=PIPE)
> > + stdout,stderr = p.communicate()
> > +
> > + self.assertIn(b'Invalid host-nodes', stderr)
> > + self.assertEquals(stdout, b'')
> > + self.assertEquals(p.returncode, 1)
> > +
> > + def test_valid_host_nodes(self):
> > + p = Popen([self.qemu_bin, '-display', 'none', '-nodefaults',
> > + '-object', 'memory-backend-ram,id=m0,'
> > + 'size=4096,host-nodes=%d' % (MAX_NODES - 1)],
> > + stderr=PIPE, stdout=PIPE)
> > + stdout,stderr = p.communicate()
> > +
> > + self.assertIn(b'host-nodes must be empty', stderr)
> > + self.assertEquals(p.returncode, 1)
>
> Perhaps this test should become part of a more comprehensive
> menory-backend-ram test.
If such a test existed, yes.
>
> Reviewed-by: Markus Armbruster <arm...@redhat.com>
Thanks!
(Although this version is broken due to the extra "l = l->next"
line and we need v2)
--
Eduardo
