When fail, translate_desc() returns negative value, otherwise the number of iovs. So we should fail when the return value is negative instead of a blindly check against zero. Reported-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx> Fixes: cc5e71075947 ("vhost: log dirty page correctly") Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 24a129fcdd61..a2e5dc7716e2 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1788,7 +1788,7 @@ static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, len, iov, 64, VHOST_ACCESS_WO); - if (ret) + if (ret < 0) return ret; for (i = 0; i < ret; i++) { -- 2.17.1