From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: null pointer at cls_api.c
Date: Thu, 05 Aug 2010 13:07:55 -0700 (PDT)
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To: franchoze@yandex.ru
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From: Franchoze Eric <franchoze@yandex.ru>
Date: Thu, 05 Aug 2010 23:24:15 +0400

> @@ -255,6 +255,11 @@ replay:
>  			kfree(tp);
>  			goto errout;
>  		}
> +
> +		if (!tp || !tp->ops) {
> +			err = -ENOENT;
> +			goto errout;
> +		}
>  		tp->ops = tp_ops;
>  		tp->protocol = protocol;
>  		tp->prio = nprio ? : TC_H_MAJ(tcf_auto_prio(*back));
> 

This patch makes no sense.

We check for "tp"  being non-NULL in the code block about the if() block you're
adding these checks to.

And tp->ops of course might be NULL here, and that's perfectly fine,
as we're about to assign "tp_ops" to it.

Looking at your backtrace I think perhaps your crash is elsewhere.