From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) (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 8F07DEAF1; Sun, 18 Feb 2024 10:32:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.201.40.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708252359; cv=none; b=eSkFK10hNH/axxRa9I7CtVnNDg0O2v/mHEAZ1jVhyyuLiRq/9Ja3rBEUXfjuQ+YzPo2oi/MKL2ER7vJ5S0P9jUa2O0MuTocboNb5cuJ3njvQWA2Nm4fEJ/D4aM/SlmhmYOTmRjBkEA3P5+OQMqfOGn7Un7bH+Apkp+emppErl0I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708252359; c=relaxed/simple; bh=QQ40rigSvgbbHgAfJv6HyWAMqrbMRDPMJB7xB30mk9g=; h=Date:From:To:Cc:Message-ID:In-Reply-To:References:Subject: MIME-Version:Content-Type; b=ls6isx/aJsICqkYLi+9ys3cMo5JAREPKYi4rwHRoUPqGWDCmdsD+VREFE8voIgUNWWY0yyH9IisIejUHMVLe5ph70h4Yke3+SUkOsnb6SvQViS1DnQ+uDDKB0zhgh3xvJZLKxGnTjsNIDmdQPg2fy/uVu0Cq53Go1Pg6Q5M/rIU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at; spf=fail smtp.mailfrom=nod.at; arc=none smtp.client-ip=195.201.40.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nod.at Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id D2C2D626FB03; Sun, 18 Feb 2024 11:25:56 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id zTwMf50YHRo2; Sun, 18 Feb 2024 11:25:56 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 34C4362348B6; Sun, 18 Feb 2024 11:25:56 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id BNvjYnE6md31; Sun, 18 Feb 2024 11:25:56 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id ECFFF64507D7; Sun, 18 Feb 2024 11:25:55 +0100 (CET) Date: Sun, 18 Feb 2024 11:25:55 +0100 (CET) From: Richard Weinberger To: chengzhihao1 Cc: Martin Kepplinger-Novakovic , Greg Kroah-Hartman , stable , patches@lists.linux.dev, ZhaoLong Wang , Miquel Raynal , Sasha Levin , linux-mtd , Vignesh Raghavendra , dpervushin , Artem Bityutskiy , linux-kernel , yi zhang , yangerkun , Henri Roosen , Melchior Franz Message-ID: <1171523562.70108.1708251955853.JavaMail.zimbra@nod.at> In-Reply-To: References: <20240122235719.206965081@linuxfoundation.org> <20240122235721.687806578@linuxfoundation.org> Subject: Re: [PATCH 5.4 058/194] mtd: Fix gluebi NULL pointer dereference caused by ftl notifier 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=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF97 (Linux)/8.8.12_GA_3809) Thread-Topic: Fix gluebi NULL pointer dereference caused by ftl notifier Thread-Index: qlWIfU/4hKJxU5rpLtwP8PpFM4piaQ== ----- Urspr=C3=BCngliche Mail ----- > Von: "chengzhihao1" >> Hi Greg, hi patch-developers, >>=20 >> wait a second. this already went into v5.4.268 but still: Doesn't this >> break userspace? >>=20 >> According to >> https://lore.kernel.org/lkml/441107100.23734.1697904580252.JavaMail.zimb= ra@nod.at/ >> where this solution seems to come from, the behaviour changes: "no >> mtdblock (hence, also no FTLs) on top of gluebi." >>=20 >> I fell accross this because of an out-of-tree module that does >> sys_mount() an mtdblock, so I won't complain about my code specifically >> :) But doesn't it break mounting, say, jffs2 inside an ubi via >> mtdblock? If so, is this really something that you want to see >> backported to old kernels? >>=20 >> Or differently put: Has this patch been picked up for old stable >> kernels by scripts or by a human? >>=20 >> I just want to make sure, and who knows, it might help others too, who >> would just do a (possibly dangerous?) revert in their trees. >>=20 >=20 > This change does affect the mounting(mtdblock based on gluebi) behavior > in userspace. It was picked into stable versions because the fixed > problem is serious and easy to be reproduced, I guess. > A temporary solution is that modify mounting source target in userspace, > just replace mtdblock with mtd char device. For example, mount -t jffs2 > mtd0 /mnt I don't think this needs backporting to stable. It's not serious because yo= u still need to be root to setup and trigger such a scenario. Thanks, //richard