Re: [PATCH] selftests: nci: Fix uninitialized family ID on missing attribute

[Hangbin Liu <hangbin.liu@linux.dev>]

On Tue, Sep 01, 2026 at 07:06:18AM +0000, Chaithanya Lagisetty wrote:
> get_family_id() walks the generic netlink CTRL_CMD_GETFAMILY reply
> looking for the CTRL_ATTR_FAMILY_ID attribute and returns the parsed
> value in the local variable "id". If the reply does not carry that
> attribute, the parsing loop never assigns "id" and the function returns
> an indeterminate stack value, which the caller stores in self->fid and
> uses for subsequent netlink requests.
> 
> Initialize "id" to 0 so a missing attribute yields a deterministic
> (invalid) family ID instead of a garbage value.
> 
> Fixes: f595cf1242f3 ("selftests: Add nci suite")
> Signed-off-by: Chaithanya Lagisetty <nagachaithanya9911@gmail.com>
> ---
>  tools/testing/selftests/nci/nci_dev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/nci/nci_dev.c b/tools/testing/selftests/nci/nci_dev.c
> index 312f84ee0444..ed306ec23895 100644
> --- a/tools/testing/selftests/nci/nci_dev.c
> +++ b/tools/testing/selftests/nci/nci_dev.c
> @@ -182,7 +182,7 @@ static int get_family_id(int sd, __u32 pid, __u32 *event_group)
>  	} ans;
>  	struct nlattr *na;
>  	int resp_len;
> -	__u16 id;
> +	__u16 id = 0;
>  	int len;
>  	int rc;
>  
> -- 
> 2.43.0
> 

Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn>