[PATCH v2 5/7] qemu: Added NFS JSON props methods

[Peter Krempa]

On Wed, Jan 06, 2021 at 15:32:30 -0600, Ryan Gahagan wrote:
> Signed-off-by: Ryan Gahagan <rgahagan at cs.utexas.edu>
> ---
>  src/qemu/qemu_block.c  | 67 +++++++++++++++++++++++++++++++++++++++-
>  src/qemu/qemu_domain.c | 70 ++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 136 insertions(+), 1 deletion(-)
> 
> diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
> index b224a550f3..cef2f7d050 100644
> --- a/src/qemu/qemu_block.c
> +++ b/src/qemu/qemu_block.c

[...]

> @@ -674,6 +697,38 @@ qemuBlockStorageSourceGetVxHSProps(virStorageSourcePtr src,
>  }
>  
>  
> +static virJSONValuePtr
> +qemuBlockStorageSourceGetNFSProps(virStorageSourcePtr src)
> +{
> +    g_autoptr(virJSONValue) server = NULL;
> +    virJSONValuePtr ret = NULL;
> +
> +    if (!(server = qemuBlockStorageSourceBuildJSONNFSServer(&src->hosts[0])))
> +        return NULL;
> +
> +    /* NFS disk specification example:
> +     * { driver:"nfs",
> +     *   user: "0",
> +     *   group: "0",
> +     *   path: "/foo/bar/baz",
> +     *   server: {type:"tcp", host:"1.2.3.4"}}
> +     */
> +    ignore_value(virJSONValueObjectCreate(&ret,
> +                                          "a:server", &server,
> +                                          "S:path", src->path, NULL));

Not checking return here means that 'ret' can still be NULL after this
call ...

> +
> +    if (src->nfs_uid != -1 &&
> +        virJSONValueObjectAdd(ret, "i:user", src->nfs_uid, NULL) < 0)

and virJSONValueObjectAdd does not check if the first argument is
non-NULL and dereferences it always, thus this can lead to a crash.

I'll add the check of return value before pushing.