[Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Eduardo Habkost]

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.

While at it, fix memory leak of the list returned by
visit_type_uint16List().

Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
Changes v1 -> v2:
* Remove extra `l = l->next` statement
  (reported by Stefano Garzarella)
* Fix (existing) leak of `host_nodes`
  (reported by Markus Armbruster)
---
 backends/hostmem.c                   | 17 +++++++++----
 tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 4 deletions(-)
 create mode 100644 tests/acceptance/host-nodes-limit.py

diff --git a/backends/hostmem.c b/backends/hostmem.c
index 1a89342039..af800284e0 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -103,14 +103,23 @@ 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);
 
-    while (l) {
+    for (l = host_nodes; l; l = l->next) {
+        if (l->value >= MAX_NODES) {
+            error_setg(errp, "Invalid host-nodes value: %d", l->value);
+            goto out;
+        }
+    }
+
+    for (l = host_nodes; l; l = l->next) {
         bitmap_set(backend->host_nodes, l->value, 1);
-        l = l->next;
     }
+
+out:
+    qapi_free_uint16List(host_nodes);
 #else
     error_setg(errp, "NUMA node binding are not supported by this QEMU");
 #endif
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 <ehabkost@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)
-- 
2.18.0.rc1.1.g3f1ff2140

Re: [Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Stefano Garzarella]

On Fri, Nov 30, 2018 at 1:28 PM Eduardo Habkost <ehabkost@redhat.com> wrote:
>
> 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.
>
> While at it, fix memory leak of the list returned by
> visit_type_uint16List().
>
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v1 -> v2:
> * Remove extra `l = l->next` statement
>   (reported by Stefano Garzarella)
> * Fix (existing) leak of `host_nodes`
>   (reported by Markus Armbruster)
> ---
>  backends/hostmem.c                   | 17 +++++++++----
>  tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
>  2 files changed, 49 insertions(+), 4 deletions(-)
>  create mode 100644 tests/acceptance/host-nodes-limit.py
>
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 1a89342039..af800284e0 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -103,14 +103,23 @@ 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);
>
> -    while (l) {
> +    for (l = host_nodes; l; l = l->next) {
> +        if (l->value >= MAX_NODES) {
> +            error_setg(errp, "Invalid host-nodes value: %d", l->value);
> +            goto out;
> +        }
> +    }
> +
> +    for (l = host_nodes; l; l = l->next) {
>          bitmap_set(backend->host_nodes, l->value, 1);
> -        l = l->next;
>      }
> +
> +out:
> +    qapi_free_uint16List(host_nodes);
>  #else
>      error_setg(errp, "NUMA node binding are not supported by this QEMU");
>  #endif
> 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 <ehabkost@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)
> --
> 2.18.0.rc1.1.g3f1ff2140
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

-- 
Stefano Garzarella
Red Hat

Re: [Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[David Hildenbrand]

On 30.11.18 13:28, Eduardo Habkost wrote:
> 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.
> 
> While at it, fix memory leak of the list returned by
> visit_type_uint16List().
> 
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v1 -> v2:
> * Remove extra `l = l->next` statement
>   (reported by Stefano Garzarella)
> * Fix (existing) leak of `host_nodes`
>   (reported by Markus Armbruster)
> ---
>  backends/hostmem.c                   | 17 +++++++++----
>  tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
>  2 files changed, 49 insertions(+), 4 deletions(-)
>  create mode 100644 tests/acceptance/host-nodes-limit.py
> 
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 1a89342039..af800284e0 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -103,14 +103,23 @@ 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);
>  
> -    while (l) {
> +    for (l = host_nodes; l; l = l->next) {
> +        if (l->value >= MAX_NODES) {
> +            error_setg(errp, "Invalid host-nodes value: %d", l->value);
> +            goto out;
> +        }
> +    }
> +
> +    for (l = host_nodes; l; l = l->next) {
>          bitmap_set(backend->host_nodes, l->value, 1);
> -        l = l->next;
>      }
> +
> +out:
> +    qapi_free_uint16List(host_nodes);
>  #else
>      error_setg(errp, "NUMA node binding are not supported by this QEMU");
>  #endif
> 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 <ehabkost@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)
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David / dhildenb

Re: [Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Markus Armbruster]

Eduardo Habkost <ehabkost@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.
>
> While at it, fix memory leak of the list returned by
> visit_type_uint16List().
>
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v1 -> v2:
> * Remove extra `l = l->next` statement
>   (reported by Stefano Garzarella)
> * Fix (existing) leak of `host_nodes`
>   (reported by Markus Armbruster)
> ---
>  backends/hostmem.c                   | 17 +++++++++----
>  tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
>  2 files changed, 49 insertions(+), 4 deletions(-)
>  create mode 100644 tests/acceptance/host-nodes-limit.py
>
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 1a89342039..af800284e0 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -103,14 +103,23 @@ 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);
>  
> -    while (l) {
> +    for (l = host_nodes; l; l = l->next) {
> +        if (l->value >= MAX_NODES) {
> +            error_setg(errp, "Invalid host-nodes value: %d", l->value);
> +            goto out;
> +        }
> +    }
> +
> +    for (l = host_nodes; l; l = l->next) {
>          bitmap_set(backend->host_nodes, l->value, 1);
> -        l = l->next;
>      }
> +
> +out:
> +    qapi_free_uint16List(host_nodes);
>  #else
>      error_setg(errp, "NUMA node binding are not supported by this QEMU");
>  #endif

Care to fix the leak in host_memory_backend_get_host_nodes(), too?

[...]

Reviewed-by: Markus Armbruster <armbru@redhat.com>

Re: [Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Eduardo Habkost]

On Fri, Nov 30, 2018 at 02:22:21PM +0100, Markus Armbruster wrote:
> Eduardo Habkost <ehabkost@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.
> >
> > While at it, fix memory leak of the list returned by
> > visit_type_uint16List().
> >
> > Reported-by: Markus Armbruster <armbru@redhat.com>
> > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> > ---
> > Changes v1 -> v2:
> > * Remove extra `l = l->next` statement
> >   (reported by Stefano Garzarella)
> > * Fix (existing) leak of `host_nodes`
> >   (reported by Markus Armbruster)
> > ---
> >  backends/hostmem.c                   | 17 +++++++++----
> >  tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
> >  2 files changed, 49 insertions(+), 4 deletions(-)
> >  create mode 100644 tests/acceptance/host-nodes-limit.py
> >
> > diff --git a/backends/hostmem.c b/backends/hostmem.c
> > index 1a89342039..af800284e0 100644
> > --- a/backends/hostmem.c
> > +++ b/backends/hostmem.c
> > @@ -103,14 +103,23 @@ 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);
> >  
> > -    while (l) {
> > +    for (l = host_nodes; l; l = l->next) {
> > +        if (l->value >= MAX_NODES) {
> > +            error_setg(errp, "Invalid host-nodes value: %d", l->value);
> > +            goto out;
> > +        }
> > +    }
> > +
> > +    for (l = host_nodes; l; l = l->next) {
> >          bitmap_set(backend->host_nodes, l->value, 1);
> > -        l = l->next;
> >      }
> > +
> > +out:
> > +    qapi_free_uint16List(host_nodes);
> >  #else
> >      error_setg(errp, "NUMA node binding are not supported by this QEMU");
> >  #endif
> 
> Care to fix the leak in host_memory_backend_get_host_nodes(), too?

I don't understand yet if there's a leak at
host_memory_backend_get_host_nodes().  Won't
visit_type_uint16List() take ownership of the list on that case?

> 
> [...]
> 
> Reviewed-by: Markus Armbruster <armbru@redhat.com>

-- 
Eduardo

Re: [Qemu-devel] [PATCH for-3.1? v2] hostmem: Validate host-nodes before setting bitmap

[Eric Blake]

On 11/30/18 6:28 AM, Eduardo Habkost wrote:
> 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.
> 
> While at it, fix memory leak of the list returned by
> visit_type_uint16List().
> 
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---

Looks like we may have 3.1-rc4 due to some CVE fixes; is this worth 
including in 3.1 as well?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Markus Armbruster]

Eduardo Habkost <ehabkost@redhat.com> writes:

> I don't understand yet if there's a leak at
> host_memory_backend_get_host_nodes().  Won't
> visit_type_uint16List() take ownership of the list on that case?

Nope.  I checked with valgrind:

    $ valgrind --leak-check=full upstream-qemu -nodefaults -S -display none -qmp stdio -object memory-backend-file,id=mem0,mem-path=x,size=4096,host-nodes=1,policy=bind
    [...]
    {"QMP": {"version": {"qemu": {"micro": 92, "minor": 0, "major": 3}, "package": "v3.1.0-rc2-48-g039d4e3df0-dirty"}, "capabilities": []}}
    {"execute": "qmp_capabilities"}
    {"return": {}}
    { "execute": "qom-get", "arguments": { "path": "mem0", "property": "host-nodes" {"execute": "qom-get", "arguments": {"path": "mem0", "property": "host-nodes"}}
    {"return": [1]}
    {"execute": "quit"}
    {"return": {}}
    {"timestamp": {"seconds": 1543592652, "microseconds": 950994}, "event": "SHUTDOWN", "data": {"guest": false}}
    ==4954== 
    ==4954== HEAP SUMMARY:
    ==4954==     in use at exit: 3,631,673 bytes in 14,706 blocks
    ==4954==   total heap usage: 51,347 allocs, 36,641 frees, 24,195,921 bytes allocated
    [...]
    ==4954== 16 bytes in 1 blocks are definitely lost in loss record 1,964 of 5,297
    ==4954==    at 0x4C3111A: calloc (vg_replace_malloc.c:752)
    ==4954==    by 0x574948D: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.5600.3)
    ==4954==    by 0x9E1CE0: opts_start_list (opts-visitor.c:228)
    ==4954==    by 0x9DAB35: visit_start_list (qapi-visit-core.c:78)
    ==4954==    by 0x99BA3A: visit_type_uint16List (qapi-builtin-visit.c:272)
    ==4954==    by 0x5F911B: host_memory_backend_set_host_nodes (hostmem.c:108)
    ==4954==    by 0x8AC7D4: object_property_set (object.c:1183)
    ==4954==    by 0x8AFC82: user_creatable_add_type (object_interfaces.c:73)
    ==4954==    by 0x8AFED2: user_creatable_add_opts (object_interfaces.c:131)
    ==4954==    by 0x8AFFCD: user_creatable_add_opts_foreach (object_interfaces.c:154)
    ==4954==    by 0xA0B9B9: qemu_opts_foreach (qemu-option.c:1171)
    ==4954==    by 0x5C6C44: main (vl.c:4415)
    ==4954== 
    ==4954== 16 bytes in 1 blocks are definitely lost in loss record 1,965 of 5,297
    ==4954==    at 0x4C3111A: calloc (vg_replace_malloc.c:752)
    ==4954==    by 0x574948D: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.5600.3)
    ==4954==    by 0x5F8FF5: host_memory_backend_get_host_nodes (hostmem.c:82)
    ==4954==    by 0x8AC739: object_property_get (object.c:1168)
    ==4954==    by 0x8AF910: object_property_get_qobject (qom-qobject.c:39)
    ==4954==    by 0x5E1736: qmp_qom_get (qmp.c:249)
    ==4954==    by 0x5D872F: qmp_marshal_qom_get (qapi-commands-misc.c:1284)
    ==4954==    by 0x9DF5C1: do_qmp_dispatch (qmp-dispatch.c:129)
    ==4954==    by 0x9DF788: qmp_dispatch (qmp-dispatch.c:171)
    ==4954==    by 0x42C0C1: monitor_qmp_dispatch (monitor.c:4085)
    ==4954==    by 0x42C3E1: monitor_qmp_bh_dispatcher (monitor.c:4157)
    ==4954==    by 0x9EEDB1: aio_bh_call (async.c:90)
    [...]
    ==4954== LEAK SUMMARY:
    ==4954==    definitely lost: 32 bytes in 2 blocks
    ==4954==    indirectly lost: 0 bytes in 0 blocks
    ==4954==      possibly lost: 2,504 bytes in 20 blocks
    ==4954==    still reachable: 3,629,137 bytes in 14,684 blocks
    ==4954==                       of which reachable via heuristic:
    ==4954==                         newarray           : 1,536 bytes in 16 blocks
    ==4954==         suppressed: 0 bytes in 0 blocks
    ==4954== Reachable blocks (those to which a pointer was found) are not shown.
    ==4954== To see them, rerun with: --leak-check=full --show-leak-kinds=all
    ==4954== 
    ==4954== For counts of detected and suppressed errors, rerun with: -v
    ==4954== Use --track-origins=yes to see where uninitialised values come from
    ==4954== ERROR SUMMARY: 24 errors from 24 contexts (suppressed: 0 from 0)

The first block shown is leaked in host_memory_backend_set_host_nodes()
on behalf of -object, the second block in
host_memory_backend_get_host_nodes() on behalf of qom-get.

Full disclosure: I hacked host_memory_backend_complete() to skip
mbind():

diff --git a/backends/hostmem.c b/backends/hostmem.c
index 1a89342039..0e40bb1ad4 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -333,7 +333,7 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
         assert(sizeof(backend->host_nodes) >=
                BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
         assert(maxnode <= MAX_NODES);
-        if (mbind(ptr, sz, backend->policy,
+        if (0 && mbind(ptr, sz, backend->policy,
                   maxnode ? backend->host_nodes : NULL, maxnode + 1, flags)) {
             if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
                 error_setg_errno(errp, errno,

Re: [Qemu-devel] [PATCH for-3.1? v2] hostmem: Validate host-nodes before setting bitmap

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> On 11/30/18 6:28 AM, Eduardo Habkost wrote:
>> 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.
>>
>> While at it, fix memory leak of the list returned by
>> visit_type_uint16List().
>>
>> Reported-by: Markus Armbruster <armbru@redhat.com>
>> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
>> ---
>
> Looks like we may have 3.1-rc4 due to some CVE fixes; is this worth
> including in 3.1 as well?

You could conceivably crash a running VM with object-add.  On the other
hand, the bug has been around for a while, and was only found by code
inspection.

Re: [Qemu-devel] [PATCH for-3.1? v2] hostmem: Validate host-nodes before setting bitmap

[Eduardo Habkost]

On Fri, Nov 30, 2018 at 06:55:39PM +0100, Markus Armbruster wrote:
> Eric Blake <eblake@redhat.com> writes:
> 
> > On 11/30/18 6:28 AM, Eduardo Habkost wrote:
> >> 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.
> >>
> >> While at it, fix memory leak of the list returned by
> >> visit_type_uint16List().
> >>
> >> Reported-by: Markus Armbruster <armbru@redhat.com>
> >> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> >> ---
> >
> > Looks like we may have 3.1-rc4 due to some CVE fixes; is this worth
> > including in 3.1 as well?
> 
> You could conceivably crash a running VM with object-add.  On the other
> hand, the bug has been around for a while, and was only found by code
> inspection.

I think the fix would be appropriate for -rc2 or -rc3, but I
don't think it's critical enough for -rc4.

-- 
Eduardo

Re: [Qemu-devel] [PATCH v2] hostmem: Validate host-nodes before setting bitmap

[Igor Mammedov]

On Fri, 30 Nov 2018 10:28:44 -0200
Eduardo Habkost <ehabkost@redhat.com> wrote:

> 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.
> 
> While at it, fix memory leak of the list returned by
> visit_type_uint16List().
> 
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
> Changes v1 -> v2:
> * Remove extra `l = l->next` statement
>   (reported by Stefano Garzarella)
> * Fix (existing) leak of `host_nodes`
>   (reported by Markus Armbruster)
> ---
>  backends/hostmem.c                   | 17 +++++++++----
>  tests/acceptance/host-nodes-limit.py | 36 ++++++++++++++++++++++++++++
>  2 files changed, 49 insertions(+), 4 deletions(-)
>  create mode 100644 tests/acceptance/host-nodes-limit.py
> 
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 1a89342039..af800284e0 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -103,14 +103,23 @@ 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);
>  
> -    while (l) {
> +    for (l = host_nodes; l; l = l->next) {
> +        if (l->value >= MAX_NODES) {
> +            error_setg(errp, "Invalid host-nodes value: %d", l->value);
> +            goto out;
> +        }
> +    }
> +
> +    for (l = host_nodes; l; l = l->next) {
>          bitmap_set(backend->host_nodes, l->value, 1);
> -        l = l->next;
>      }
> +
> +out:
> +    qapi_free_uint16List(host_nodes);
>  #else
>      error_setg(errp, "NUMA node binding are not supported by this QEMU");
>  #endif
> 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 <ehabkost@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)