From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F39C408026 for ; Wed, 2 Sep 2026 09:01:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788339666; cv=none; b=fISI3jEREJMCQMt70eMg4nC71e2ju68fKJCB1VvVfpm7B1fIsTwJwI+o4IqkqEtf4F/0GpADungatDrkXK8tEDvkv4L0kNmw/+owxSikixtu0re/xw1UubHji72nAWkuLi9a1aUraFUmojyTjYUoFFtvoqwVbasFnuOHefJo514= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788339666; c=relaxed/simple; bh=XSK+zRuSMVw8jLK60WcdQQofoqidIRH6crZyCiqiZN8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Vce7+tPs72ffXy+yzrSOyPn+jd3r9HLKPgH0gjgziGiMomSKpXMNCQKXmc6bDC9HWIwFxI4MAsjIkHGlNG+pLoYe1Fx0X8I9W/l6KR/fGxQ8k8mK7cJOADBZ7zGCn8Is1qFPyN56Lv/zwvm8uUQPzUBlbQfHZSYX9ohpTNjFZLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=strlen.de; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=strlen.de Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id D410E60405; Wed, 02 Sep 2026 11:00:58 +0200 (CEST) Date: Wed, 2 Sep 2026 11:00:58 +0200 From: Florian Westphal To: bot+bpf-ci@kernel.org Cc: bpf@vger.kernel.org, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org, yonghong.song@linux.dev, mason@kernel.org, ihor.solodrai@linux.dev Subject: Re: [PATCH bpf] selftests/bpf: Add tests to assert that netfilter progs cannot write to skb Message-ID: References: <20260902065226.25201-1-fw@strlen.de> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: bot+bpf-ci@kernel.org wrote: > > Assert that bpf netfilter program type exposes readonly access to the > > skb, either via direct packet access or via dynptr API. > This isn't a bug, but since netfilter progs have no direct packet access, > would it be clearer to describe this case as writing through ctx->skb (BTF > walk) instead of 'direct packet access'? The test (ctx->skb->data[0] = 0) > walks a BTF pointer, which is why the expected message is 'cannot write > into rdonly_untrusted_mem' rather than a packet-access error. I'll shorten this to: "Assert that bpf netfilter programs do not allow skb write access." I'll also follow the other suggested changes to function names.