Subject: Re: [iproute PATCH v3 2/5] nstat: Fix for potential NULL pointer dereference

From: Stephen Hemminger <[email-masked]>
Date: Mon, 21 Aug 2017 17:19:45 -0700

On Mon, 21 Aug 2017 12:03:05 +0200
Phil Sutter <[email-masked]> wrote:

> If the string at 'p' contains neither space not newline, 'p' will become
> NULL. Make sure this isn't the case before dereferencing it.
> 
> Signed-off-by: Phil Sutter <[email-masked]>
> ---
> Changes since v2:
> - Call abort() if 'p' becomes NULL.
> ---
>  misc/nstat.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/misc/nstat.c b/misc/nstat.c
> index a4dd405d43a93..56e9367e99736 100644
> --- a/misc/nstat.c
> +++ b/misc/nstat.c
> @@ -217,6 +217,8 @@ static void load_ugly_table(FILE *fp)
>  			n->next = db;
>  			db = n;
>  			p = next;
> +			if (!p)
> +				abort();
>  		}
>  		n = db;
>  		if (fgets(buf, sizeof(buf), fp) == NULL)

This doesn't do anything better than just dereferencing NULL.
In either case program crashes with no useful information to user.
Not applying this.