vhost: correctly check the return value of translate_desc() in log_used()
authorJason Wang <jasowang@redhat.com>
Tue, 19 Feb 2019 06:53:44 +0000 (14:53 +0800)
committerDavid S. Miller <davem@davemloft.net>
Tue, 19 Feb 2019 21:14:45 +0000 (13:14 -0800)
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.

Detected by CoverityScan, CID# 1442593:  Control flow issues  (DEADCODE)

Fixes: cc5e71075947 ("vhost: log dirty page correctly")
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/vhost/vhost.c

index 24a129f..a2e5dc7 100644 (file)
@@ -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++) {