From: Pierre Morel Date: Thu, 10 Sep 2015 14:35:08 +0000 (+0200) Subject: virtio/s390: handle failures of READ_VQ_CONF ccw X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ad2aa04218de9bd734d593adb0ac59854ec0cb68;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git virtio/s390: handle failures of READ_VQ_CONF ccw In virtio_ccw_read_vq_conf() the return value of ccw_io_helper() was not checked. If the configuration could not be read properly, we'd wrongly assume a queue size of 0. Let's propagate any I/O error to virtio_ccw_setup_vq() so it may properly fail. Signed-off-by: Pierre Morel Signed-off-by: Cornelia Huck Signed-off-by: Michael S. Tsirkin --- diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index f8d8fdb26b72..e9fae30fafda 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -400,12 +400,16 @@ static bool virtio_ccw_kvm_notify(struct virtqueue *vq) static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, struct ccw1 *ccw, int index) { + int ret; + vcdev->config_block->index = index; ccw->cmd_code = CCW_CMD_READ_VQ_CONF; ccw->flags = 0; ccw->count = sizeof(struct vq_config_block); ccw->cda = (__u32)(unsigned long)(vcdev->config_block); - ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF); + ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF); + if (ret) + return ret; return vcdev->config_block->num; } @@ -503,6 +507,10 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, goto out_err; } info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i); + if (info->num < 0) { + err = info->num; + goto out_err; + } size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN)); info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); if (info->queue == NULL) {