qemu: fix CVE-2023-3301

qemu: hotplug/hotunplug mlx vdpa device to the occupied addr port,
then qemu core dump occurs after shutdown guest

Reference:
https://nvd.nist.gov/vuln/detail/CVE-2023-3301

(From OE-Core rev: 82bf6c4cba88dc9f25caf14d60e79ce0c366919c)

Signed-off-by: Yogita Urade <yogita.urade@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 66 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index 15eba6163f..c1ac245f9f 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -37,6 +37,7 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://qemu-guest-agent.udev \
            file://ppc.patch \
            file://CVE-2023-0330.patch \
+           file://CVE-2023-3301.patch \
            "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"
 
diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2023-3301.patch b/meta/recipes-devtools/qemu/qemu/CVE-2023-3301.patch
new file mode 100644
index 0000000000..977f017ed2
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/CVE-2023-3301.patch
@@ -0,0 +1,65 @@
+From a0d7215e339b61c7d7a7b3fcf754954d80d93eb8 Sep 17 00:00:00 2001
+From: Ani Sinha <anisinha@redhat.com>
+Date: Wed, 2 Aug 2023 09:25:27 +0000
+Subject: [PATCH] vhost-vdpa: do not cleanup the vdpa/vhost-net structures if
+ peer nic is present
+
+When a peer nic is still attached to the vdpa backend, it is too early to free
+up the vhost-net and vdpa structures. If these structures are freed here, then
+QEMU crashes when the guest is being shut down. The following call chain
+would result in an assertion failure since the pointer returned from
+vhost_vdpa_get_vhost_net() would be NULL:
+
+do_vm_stop() -> vm_state_notify() -> virtio_set_status() ->
+virtio_net_vhost_status() -> get_vhost_net().
+
+Therefore, we defer freeing up the structures until at guest shutdown
+time when qemu_cleanup() calls net_cleanup() which then calls
+qemu_del_net_client() which would eventually call vhost_vdpa_cleanup()
+again to free up the structures. This time, the loop in net_cleanup()
+ensures that vhost_vdpa_cleanup() will be called one last time when
+all the peer nics are detached and freed.
+
+All unit tests pass with this change.
+
+CC: imammedo@redhat.com
+CC: jusual@redhat.com
+CC: mst@redhat.com
+Fixes: CVE-2023-3301
+Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2128929
+Signed-off-by: Ani Sinha <anisinha@redhat.com>
+Message-Id: <20230619065209.442185-1-anisinha@redhat.com>
+Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
+Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
+
+CVE: CVE-2023-3301
+
+Upstream-Status: Backport [https://github.com/qemu/qemu/commit/a0d7215e339b61c7d7a7b3fcf754954d80d93eb8]
+
+Signed-off-by: Yogita Urade <yogita.urade@windriver.com>
+---
+ net/vhost-vdpa.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
+index 2b4b85d8f..8dbe929c1 100644
+--- a/net/vhost-vdpa.c
++++ b/net/vhost-vdpa.c
+@@ -158,6 +158,15 @@ err_init:
+ static void vhost_vdpa_cleanup(NetClientState *nc)
+ {
+     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
++
++    /*
++     * If a peer NIC is attached, do not cleanup anything.
++     * Cleanup will happen as a part of qemu_cleanup() -> net_cleanup()
++     * when the guest is shutting down.
++     */
++    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
++       return;
++    }
+     struct vhost_dev *dev = &s->vhost_net->dev;
+
+     qemu_vfree(s->cvq_cmd_out_buffer);
+--
+2.40.0