[PATCH v3] lib/graph: lib/graph: fix memset with NULL

[David Marchand]

On Wed, Jun 25, 2025 at 11:29 AM Marat Khalili <marat.khalili at huawei.com> wrote:
>
> This was flagged by undefined behaviour sanitizer: memset should not be
> called with NULL first argument. (memset requires first argument to be
> pointer to a memory object, so passing NULL may result in an undefined
> behaviour including among other things optimizer potentially removing
> code paths depending on stat->xstat_count being NULL.)
>
> Sanitizer message:
>
>     lib/graph/graph_stats.c:473:2: runtime error: null pointer passed as
>     argument 1, which is declared to never be null
>
> Add a check that stat->xstat_cntrs is not zero before the call, since
> stat->xstat_count can only be NULL when stat->xstat_cntrs is zero.
>
> Fixes: 070db97e017 ("graph: support node xstats")
>
> Signed-off-by: Marat Khalili <marat.khalili at huawei.com>

Just a fyi, I added your patch as part of my series, since running
with UBSan in GHA required this fix.

We may still take your fix as is, so I'll leave it in patchwork.


-- 
David Marchand