The code handles this case correctly we merely skip the loop. However it
is probably best to return an explicit error.

Acked-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Eyal Moscovici <eyal.moscovici@oracle.com>
---
 qemu-img.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/qemu-img.c b/qemu-img.c
index 4a06ab7fe8..a1b507a0be 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3086,6 +3086,11 @@ static int img_map(int argc, char **argv)
     }
 
     length = blk_getlength(blk);
+    if (length < 0) {
+        error_report("Failed to get size for '%s'", filename);
+        return 1;
+    }
+
     while (curr.start + curr.length < length) {
         int64_t offset = curr.start + curr.length;
         int64_t n;
-- 
2.17.2 (Apple Git-113)

On 5/6/20 4:34 PM, Eyal Moscovici wrote:
> The code handles this case correctly we merely skip the loop. However it
> is probably best to return an explicit error.
> 
> Acked-by: Mark Kanda <mark.kanda@oracle.com>
> Signed-off-by: Eyal Moscovici <eyal.moscovici@oracle.com>
> ---
>   qemu-img.c | 5 +++++
>   1 file changed, 5 insertions(+)

Reviewed-by: Eric Blake <eblake@redhat.com>

> 
> diff --git a/qemu-img.c b/qemu-img.c
> index 4a06ab7fe8..a1b507a0be 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -3086,6 +3086,11 @@ static int img_map(int argc, char **argv)
>       }
>   
>       length = blk_getlength(blk);
> +    if (length < 0) {
> +        error_report("Failed to get size for '%s'", filename);
> +        return 1;
> +    }
> +
>       while (curr.start + curr.length < length) {
>           int64_t offset = curr.start + curr.length;
>           int64_t n;
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org