From: Michael S. Tsirkin Date: Mon, 28 Apr 2014 13:08:23 +0000 (+0300) Subject: virtio: validate config_len on load X-Git-Tag: qemu-xen-4.6.0-rc1~473^2~11 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=a890a2f9137ac3cf5b607649e66a6f3a5512d8dc;p=qemu-upstream-4.6-testing.git virtio: validate config_len on load Malformed input can have config_len in migration stream exceed the array size allocated on destination, the result will be heap overflow. To fix, that config_len matches on both sides. CVE-2014-0182 Reported-by: "Dr. David Alan Gilbert" Signed-off-by: Michael S. Tsirkin Signed-off-by: Juan Quintela -- v2: use %ix and %zx to print config_len values Signed-off-by: Juan Quintela --- diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index a70169af0..7f4e7eca0 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -898,6 +898,7 @@ int virtio_set_features(VirtIODevice *vdev, uint32_t val) int virtio_load(VirtIODevice *vdev, QEMUFile *f) { int i, ret; + int32_t config_len; uint32_t num; uint32_t features; uint32_t supported_features; @@ -924,7 +925,12 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f) features, supported_features); return -1; } - vdev->config_len = qemu_get_be32(f); + config_len = qemu_get_be32(f); + if (config_len != vdev->config_len) { + error_report("Unexpected config length 0x%x. Expected 0x%zx", + config_len, vdev->config_len); + return -1; + } qemu_get_buffer(f, vdev->config, vdev->config_len); num = qemu_get_be32(f);