On 2021/2/12 上午12:25, Stefano Garzarella wrote:
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);
}
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
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