Commit 65b709586e222fa6ffd4166ac7fdb5d5dad113ee upstream. Before this patch, if 'offset + len' was equal to sizeof(struct virtio_net_config), the entire buffer wasn't filled, returning incorrect values to the caller. Since 'vdpasim->config' type is 'struct virtio_net_config', we can safely copy its content under this condition. Commit 65b709586e22 ("vdpa_sim: add get_config callback in vdpasim_dev_attr") unintentionally solved it upstream while refactoring vdpa_sim.c to support multiple devices. But we don't want to backport it to stable branches as it contains many changes. Fixes: 2c53d0f64c06 ("vdpasim: vDPA device simulator") Cc: <stable@xxxxxxxxxxxxxxx> # 5.10.x Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> --- drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c index 6a90fdb9cbfc..8ca178d7b02f 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -572,7 +572,7 @@ static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset, { struct vdpasim *vdpasim = vdpa_to_sim(vdpa); - if (offset + len < sizeof(struct virtio_net_config)) + if (offset + len <= sizeof(struct virtio_net_config)) memcpy(buf, (u8 *)&vdpasim->config + offset, len); } -- 2.29.2