From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) (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 356CB34887C for ; Wed, 20 May 2026 03:21:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779247297; cv=none; b=r/2VhgCzEFKnqgRk2Bbuw/87vMUc1Q2t8rLHsmEpkHy3A5lcetRA/s7EaxO8eJCS0WUTOj+tH4ztVCMjbezKQMdV2v/3vD0el/JPDk2wIbBNg1NvAFpp63lokPZNUy6fYDXOapDmZ+FhQZMRqkHmfy1SieBNMmYsY6I8WNdsdUE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779247297; c=relaxed/simple; bh=xpchlKUnuj4uaAkP989tjyID+0/RO5S/wlHteACg1as=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fJPtl4Fg7AyWYVJg4eFTwn7/hqFSu7Eir+ECeyjvEynBZfFAluc7k4yIr5ZsoaibFBRlE2J21b+bYHlyQ7Nm1FANOIapQxysJzs7oLUXLLeF0i934ZZrIa8hP2QP/kWYfgUzdfXUu2PPeLvYWTaXDZQfIEoKzmrqilujKUL1ehM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=S3vnyAn9; arc=none smtp.client-ip=95.215.58.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="S3vnyAn9" Date: Wed, 20 May 2026 11:21:21 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779247291; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QNMwdoa0LlYtMoqIK5S8Dh6GrHLXivHDLFIZ2WwXCbs=; b=S3vnyAn97qkANlwQnCto3no2q7tfR3m0ldvWiTUHrQE3RbAFIZn16kOJcJRouccAqFxSZh xiq9GVkluhJJLGWCKoiMxi1A5IXjiBUR/k6D+3dGrmMSXWo/oGZa/UbH3u6mfMi/Xftrnq f6VfVBErnwzUAtsYrlrmGfJcaBO9Bfg= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Hao Li To: Vladimir Zapolskiy Cc: Vlastimil Babka , Harry Yoo , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/slab: fix probable issue of dentries registration under /sys/kernel/slab Message-ID: References: <20260520011019.1707010-1-vladimir.zapolskiy@linaro.org> 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: <20260520011019.1707010-1-vladimir.zapolskiy@linaro.org> X-Migadu-Flow: FLOW_OUT On Wed, May 20, 2026 at 04:10:19AM +0300, Vladimir Zapolskiy wrote: > L2TP/IP and L2TP/IPv6 protocol names contain a slash symbol, however these > names are blindly used as symlinks to slab cache objects registered under > /sys/kernel/slab. This kind of symlink creation is successful, but its > dentry is obviously broken, as well it breaks the access to the list of > /sys/kernel/slab dentries. > > Likely L2TP protocol renames cannot be done, since the defined protocol > names are exposed over /proc/net/protocols for years, but the symlink > names can be renamed, because they are yet to be properly created, and > this should be eventually done by this change. > > The problem manifests itself, if CONFIG_L2TP_IP build symbol is selected. Hello, thanks for the patch. Could L2TP possibly be loaded as a module? I noticed that __kmem_cache_create_args can also call into sysfs_slab_alias. If L2TP is loaded as a module after boot and dynamically creates a slub cache, it may bypass your fix.. -- Thanks, Hao