vhost: fix length for cross region descriptor
commit bd97120fc3d1a11f3124c7c9ba1d91f51829eb85 upstream.
If a single descriptor crosses a region, the
second chunk length should be decremented
by size translated so far, instead it includes
the full descriptor length.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 51e4c1e..1a9e2a9 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1074,7 +1074,7 @@
}
_iov = iov + ret;
size = reg->memory_size - addr + reg->guest_phys_addr;
- _iov->iov_len = min((u64)len, size);
+ _iov->iov_len = min((u64)len - s, size);
_iov->iov_base = (void __user *)(unsigned long)
(reg->userspace_addr + addr - reg->guest_phys_addr);
s += size;