From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5583AC27C76 for ; Wed, 25 Jan 2023 22:12:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234993AbjAYWMJ (ORCPT ); Wed, 25 Jan 2023 17:12:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230016AbjAYWMH (ORCPT ); Wed, 25 Jan 2023 17:12:07 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E970F5CE53; Wed, 25 Jan 2023 14:12:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 84531616BE; Wed, 25 Jan 2023 22:12:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5778BC433D2; Wed, 25 Jan 2023 22:12:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674684725; bh=YIt0F6yGYF02jNoG01C/IBN+akaDldiFwJFAsSjjgEY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SzLA+p9TSEXTBNzXvmW1q95QHaEIdZy65oyeRRNkVjCNq+55ndLayoY6LZblCgnYj TrNYzLlWatR6iZsW/4+GpnibUZ7I3HliD665lHc2Tu9k6sQHsteUPJXltaFsuTlid2 Z5PNZ29S/ADZ63P7zeMObU1zZQ5OB2lMusNMLHJKE5XFS/5EQPtnjJnI2X3ok/fCee YOSaPOdSOFaCmLXwcLi0FFZK1uHPwZoAG7RYUEfBBl9G77/8a6lhCLRw/iZmjUlF00 89tGaS0h5a4oOSPc9WdVLmBhHnRbO6UioN+t6bXxS9gKeHbynWYDA1ZoiW3ZWD6NHD 6jEa40qPngvBw== Date: Wed, 25 Jan 2023 23:11:59 +0100 From: Wolfram Sang To: Bartosz Golaszewski Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: Re: [PATCH v3] i2c: dev: don't allow user-space to deadlock the kernel Message-ID: Mail-Followup-To: Wolfram Sang , Bartosz Golaszewski , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski References: <20230118134940.240102-1-brgl@bgdev.pl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="CaxbyIFftu0Vi95h" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --CaxbyIFftu0Vi95h Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > So, this code handled all my stress-testing well so far. I'll try to > think of some more ideas until this evening, but likely I will apply it > later. Nonetheless, more review eyes are still welcome! Ah yes, I now recalled why I had the gut feeling that this solution is not complete. See this mail thread from 2015: https://lkml.iu.edu/hypermail/linux/kernel/1501.2/01700.html There are still drivers using i2c_del_adapter()+kfree(), so removing the completion could cause use-after-free there, or? --CaxbyIFftu0Vi95h Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmPRqSsACgkQFA3kzBSg Kbbf9w/7BFVjt+dIMmMYA4nX1DYb1qibMoATRwcbxIVsIh4/dKHHzdVj2ptRpV1Q LDzag3Jq6Bw/3w0++6//8CkYLS0u7+NjF86mKX5H1WtT477uuGsdw5upCe9lDNiy 3Ra6I+eDZ2y8dVjJMFGSBNQWH4zVjmlKeQgGb32/KKcZ6L52kxXQl8os9IQLadYW 23+zhsjoa4odM7I9dqLXFDovmvivdu9FfJIsvRRCp6Rugmd/CqLhSSDMKzYUYnFW wLzSdmfa99ajnEXD3UucF82QhuiOatOJ9Y84YrorfB2tKGam1fXZgdKNfrAo/O4s 301ZzQahDiQXVaMxyD6aXZLPigNCmnVh76ezStVbNaSh6vO/6bsBRy/xRGYjges8 sJfvS+DV8mcxxX4YebRbo6jTskU372LcpopkyybFa0GvAzVHBO6KCanLxyPalLaO aM8fBQAkCuo1KN6WyTnbjZILw8itY/O03gvvmDbf0gk+rSecjKGE4PAE+lyHTpVP 2MoQypjKIBiB0RgnyEa+eMWNm/HLuAoZ02ukmhaxm321ZJyI6CpGcXZ7b6QDPIZL NoPmnpnSbDJBVPolpH2WEDxMu66o1frKgzAnpr0AqqbUS0zmrsZAG/NgCxpYVZq+ 9r2cA32crnCHT3hoPjP8fkOcObDHqPWh7SPBzMGkIAojDIPjTh0= =FpT/ -----END PGP SIGNATURE----- --CaxbyIFftu0Vi95h--