Re: [Qemu-trivial] [Qemu-devel] [trivial for-2.6] util/id: fully allocate names table

[Markus Armbruster <armbru@redhat.com>]

John Snow <jsnow@redhat.com> writes:

> Trivial: this array should be allocated to have ID_MAX entries always.
> Otherwise if someone were to forget to expand this table, the assertion
> in the id generator won't actually trigger; it will read junk data.

You mean this one:

    assert(id < ID_MAX);

The assertion is crap, because it fails to protect array access
id_subsys_str[id].  Here's one that does:

    assert(0 <= id && id < ARRAY_SIZE(id_subsys_str));

> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  util/id.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/util/id.c b/util/id.c
> index bcc64d8..b7ca4d2 100644
> --- a/util/id.c
> +++ b/util/id.c
> @@ -29,7 +29,7 @@ bool id_wellformed(const char *id)
>  
>  #define ID_SPECIAL_CHAR '#'
>  
> -static const char *const id_subsys_str[] = {
> +static const char *const id_subsys_str[ID_MAX] = {
>      [ID_QDEV]  = "qdev",
>      [ID_BLOCK] = "block",
>  };