On Tue, 17 Aug 2021, Nigel Croxon wrote:
> To meet requirements of Common Criteria certification vulnerablility
> assessment. Static code analysis has been run and found the following
> error:
> buffer_size_warning: Calling "strncpy" with a maximum size
> argument of 16 bytes on destination array "ve->name" of
> size 16 bytes might leave the destination string unterminated.
>
> The change is to make the destination size to fit the allocated size.
>
> Signed-off-by: Nigel Croxon <ncroxon@xxxxxxxxxx>
> ---
> super-ddf.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/super-ddf.c b/super-ddf.c
> index dc8e512f..486183ed 100644
> --- a/super-ddf.c
> +++ b/super-ddf.c
> @@ -2637,9 +2637,10 @@ static int init_super_ddf_bvd(struct supertype *st,
> ve->init_state = DDF_init_not;
>
> memset(ve->pad1, 0xff, 14);
> - memset(ve->name, ' ', 16);
> + memset(ve->name, ' ', 15);
> + ve->name[15] = '\0';
> if (name)
> - strncpy(ve->name, name, 16);
> + strncpy(ve->name, name, 15);
This is not correct.
ve->name is *not* required to be nul-terminated. It is a string that
can be up to 16 bytes long. If it is less than 16 bytes, it is
nul-padded.
Probably the way to get coverity to stop complaining is to use memcpy.
if (name) {
int l = strlen(name;
if (l > 16)
l = 16;
memcpy(ve->name, name, l);
}
Probably the ->name should be initialized to '\0', not spaces.
https://www.snia.org/sites/default/files/SNIA_DDF_Technical_Position_v2.0.pdf
describes the format. Some fields are specified as being padded with
spaces, but not VD_Name (which is ve->name).
The field is specified as being either ASCII or "UNICODE" (which doesn't
make any sense as "UNICODE" is not a byte-encoding. Presumably it means
"UTF-8") and that:
If this field is not used, all bytes MUST be set to zero.
So it should probably be zero-padded. But there is definitely no
requirement for it to be zero-terminated.
Thanks,
NeilBrown
> ddf->virt->populated_vdes =
> cpu_to_be16(be16_to_cpu(ddf->virt->populated_vdes)+1);
>
> --
> 2.29.2
>
>
