From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0855537DE81; Fri, 10 Apr 2026 10:28:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775816912; cv=none; b=g7PbBAeQGrcgOeqGCPZdoYkXMcgA8PEIwhkb+MukiX7SSCB6Uihv21wkyOJKgYvan5tcaAonoDyrTwdP7dt+HsyDlBHpCRO776Fvd1eYkEnSsrn7+1mL2vUNFMWXhM+eboretdPM6qMK6tdyoskXqBYo0ibZR3dFm6zRerL+jbQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775816912; c=relaxed/simple; bh=evFuOJspE7UTTSF9DREpgNuK2GUXs3TlE+bzd02GoWM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iC6czD5rIEtP2chR0EeHCjCqrGrnnYlZILr5WU2wvB8xR9D98HDrvZ40dd/EpW7NbHJROwe64wrUXA4mIwI6LU91v8Xfl4JhFyniDRObfVRyLyYzYRtNEL8LCeKCtoWC8AQM2R/p0YOmJCtJxLH7K+R7ITJp3KqbSzjWQpD7Isk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V0mpVWo5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V0mpVWo5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3122C19421; Fri, 10 Apr 2026 10:28:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775816911; bh=evFuOJspE7UTTSF9DREpgNuK2GUXs3TlE+bzd02GoWM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=V0mpVWo5Kh9jZB558akSRe8MfnYkNDX72Fq9HoWXHmthJOzSmgai0TQhA6H+GDj3/ HGsPMCXnjtNUB0oL/oP9pr5rcmAXQ+Ql4DpbQHpxJbC/f6agmMckZbRLvT4q7tMk6F LX9jXjrkvzOf9nf1fOJwth/3Hwy3xIzjctSGfb2+pWOwJbiiUEUmYpen4fvFOlgoyV EK5JrSMByWHO5DsobylAaN15SP8v0Ojc3Zw/4fJaCkAVn6+DIu+VKZ/RgXZdBF9H7a 7VMY3U03vBVW0yMEAJ/26hYk3j4JJXQDLDBV/kgdJp3ci1WNhqfZhmiEpJfnoepUSJ AHbbTu2pusd7g== Date: Fri, 10 Apr 2026 11:28:27 +0100 From: Simon Horman To: Greg Kroah-Hartman Cc: Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "David S. Miller" , Eric Dumazet , Paolo Abeni , linux-hams@vger.kernel.org, Yizhe Zhuang , stable Subject: Re: [PATCH net] netrom: do some basic forms of validation on incoming frames Message-ID: <20260410102827.GT469338@kernel.org> References: <2026040730-untagged-groin-bbb7@gregkh> <20260409190328.GS469338@kernel.org> <20260409203235.6b9329f0@kernel.org> <2026041026-excuse-slashing-c4ee@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@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: <2026041026-excuse-slashing-c4ee@gregkh> On Fri, Apr 10, 2026 at 07:24:36AM +0200, Greg Kroah-Hartman wrote: > On Thu, Apr 09, 2026 at 08:32:35PM -0700, Jakub Kicinski wrote: > > On Thu, 9 Apr 2026 20:03:28 +0100 Simon Horman wrote: > > > I expect that checking skb->len isn't sufficient here > > > and pskb_may_pull needs to be used to ensure that > > > the data is also available in the linear section of the skb. > > > > Or for simplicity we could also be testing against skb_headlen() > > since we don't expect any legit non-linear frames here? Dunno. Sure, that's find by me if it leads to simpler code than using pskb_may_pull(). Else I'd lean towards pskb_may_pull() as it is a more general approach that feels worth proliferating. > I'll be glad to change this either way, your call. Given that this is > an obsolete protocol that seems to only be a target for drive-by fuzzers > to attack, whatever the simplest thing to do to quiet them up I'll be > glad to implement. > > Or can we just delete this stuff entirely? :) Deleting sounds good to me. But we likely need a deprecation process. In which case fixing these bugs still makes sense for the short term.