Re: [Qemu-devel] [PATCH v3 4/6] vmdk: Check descriptor file length when reading it

[Fam Zheng <famz@redhat.com>]

On Wed, 12/03 15:17, Max Reitz wrote:
> On 2014-12-03 at 11:28, Fam Zheng wrote:
> >Since a too small file cannot be a valid VMDK image, and also since the
> >buffer's first 4 bytes will be unconditionally examined by
> >vmdk_open_sparse, let's error out the small file case to be clear.
> >
> >Signed-off-by: Fam Zheng <famz@redhat.com>
> >Reviewed-by: Markus Armbruster <armbru@redhat.com>
> >---
> >  block/vmdk.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> >diff --git a/block/vmdk.c b/block/vmdk.c
> >index 82257cd..045fd7a 100644
> >--- a/block/vmdk.c
> >+++ b/block/vmdk.c
> >@@ -557,6 +557,11 @@ static char *vmdk_read_desc(BlockDriverState *file, uint64_t desc_offset,
> >          return NULL;
> >      }
> >+    if (size < 4) {
> >+        error_setg_errno(errp, -size, "File is too small, not a valid image");
> 
> 0 <= size < 4, strerror(0..-3) doesn't make a whole lot of sense. Should be
> simply error_setg() instead of error_setg_errno().

Yes, fixing.

Fam