From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (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 E527F41C63 for ; Tue, 6 Jan 2026 22:58:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767740287; cv=none; b=idt4R5xxhzlz+ju1VqSz5hUX7F93p3n9C539FE/AvxgzjlTFjlIEWvnsOQu63vVC9GdBLatF0dKb+CTQxYiw7tcDyzMltXhPjDJDztJKbGmgXAW6VUA6XdDRa9L+4J7cITiWeQhhUfn1gTZ9T9NcDWUsbUr6p62ToFpCavDHWDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767740287; c=relaxed/simple; bh=FBSAdrJuSHYp8a3YsIbBRZd3C83eAdDNhH1Rby2AUss=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CZDbgGYIkozK0Lwgz0qg8p0KrZMKMwqUOR1jtZdskhb/1xYlklaSRhrDZcqkpX9iL5mCoZ85aBw8g1erFHeVA2cH+0ChlRRc/l69b/5CotQo0udA74g/pX3o8IEpFMkqZK4b6xvgcqSvlwd2cKRAt/F3luWHgn90QpjtULzMdAE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=A19Ypdaq; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="A19Ypdaq" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=44keKZ9ZsFvsH0+e6QQR1BG01AuMEbT1Xr48EFlkfEE=; b=A19YpdaqK4qCuhbFywAoHiQc3E uN6eDyqhHz3z9GIw72G94zyR7Hhu7QolH3EK9EwreFN4nbfH8Vos9Tdm/ZgM7U+iJX1CQTAxyW2P1 4hF0OOycniZHFymwUtH2s7EKDhGXcyODK/6/mCaddzBsIK+xIhn3QrENrvJ/skhlx1UEalqWQtiP5 +9kA6X78OBieJJRFGref0U6teFOZbquCECbA6bfzxAPbdF2EWGikVbgNcX0EvhlDkgbx6YPXpbnLW tlHz9i3Z2mm1CZrYowOJ0wJ+ig+l57Upqe4MQh512PKBta2H1bTU0D/k/DbfN4s15dgZMZ9iSX8/Z ykK+SjgA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.99 #2 (Red Hat Linux)) id 1vdG1F-0000000GVt0-2OQa; Tue, 06 Jan 2026 22:59:17 +0000 Date: Tue, 6 Jan 2026 22:59:17 +0000 From: Al Viro To: Christian Brauner Cc: linux-fsdevel@vger.kernel.org, Jan Kara , Jeff Layton , Amir Goldstein , Lennart Poettering , Zbigniew =?utf-8?Q?J=C4=99drzejewski-Szmek?= , Josef Bacik Subject: Re: [PATCH 3/3] fs: add immutable rootfs Message-ID: <20260106225917.GL1712166@ZenIV> References: <20260102-work-immutable-rootfs-v1-0-f2073b2d1602@kernel.org> <20260102-work-immutable-rootfs-v1-3-f2073b2d1602@kernel.org> <20260104072743.GI1712166@ZenIV> <20260104074145.GJ1712166@ZenIV> <20260106-verpachten-antrag-5b610d1ec4d0@brauner> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20260106-verpachten-antrag-5b610d1ec4d0@brauner> Sender: Al Viro On Tue, Jan 06, 2026 at 11:07:32PM +0100, Christian Brauner wrote: > > Afaict, FS_IMMUTABLE_FL can be cleared by a sufficiently privileged > process breaking the promise that this is a permanently immutable > rootfs. Not on ramfs: int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, struct file_kattr *fa) { struct inode *inode = d_inode(dentry); struct file_kattr old_ma = {}; int err; if (!inode->i_op->fileattr_set) return -ENOIOCTLCMD; and that's it, priveleges do not matter.