From dc799dbb98c726fc783e50badac4865e24af65d9 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 6 Apr 2020 17:45:52 +0300 Subject: [PATCH] vdpa: Fix pointer math bug in vdpasim_get_config() [ Upstream commit cf16fe9243bfa2863491026fc727618c7c593c84 ] If "offset" is non-zero then we end up copying from beyond the end of the config because of pointer math. We can fix this by casting the struct to a u8 pointer. Fixes: 2c53d0f64c06 ("vdpasim: vDPA device simulator") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/20200406144552.GF68494@mwanda Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin --- 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 3554f8de00e64..4907c1cfe6671 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -521,7 +521,7 @@ 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)) - memcpy(buf, &vdpasim->config + offset, len); + memcpy(buf, (u8 *)&vdpasim->config + offset, len); } static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset, -- 2.47.2