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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HzRYE13j; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 117BB60A2603; Tue, 10 Nov 2026 20:46:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HzRYE13j Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47D441F008AB; Tue, 10 Nov 2026 20:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794343564; bh=rMRPONQOYjAF9HKKBayLjA2YuezRW4mL6HNg3dL1nlo=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HzRYE13jB8RdQv3aSy711gVTQF5aN3kmny3Bm+Tqd6DGpMnW/UdmBhwvuV3tDKwWA qBQkdAe99fCfyY4HwhHW6vpWLb11tiX1rqZm0gqSH24JDOLS4Qw49hrn6RKPLTZ5tX 8yK911/kTi5YKMv0Zeg0t9hinxeSS095ez81rveTvDj3lhZIp5MNrpZ0TzLVXjAROD H+8sIgKlcwqIAFUbaPlcIA/mKF9hJXlPwet/3tzJzqABID/FKMqpm7AOyUBYjWme3C 0bNu78jINjA9S3ckBH6UNePnv8GkZJATc2s+TTg1AYJLjtNo7jNr7qgY8y7Qdi6pm5 ugUx9cOxV5vJQ== Date: Tue, 10 Nov 2026 21:45:52 +0100 From: Gao Xiang To: Christian Brauner Cc: linux-fsdevel@vger.kernel.org, Jann Horn , Chris Mason , Josef Bacik , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Alexander Viro , Jan Kara , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, driver-core@lists.linux.dev, linux-mm@kvack.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, apparmor@lists.ubuntu.com, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, fuse-devel@lists.linux.dev, linux-efi@vger.kernel.org, xen-devel@lists.xenproject.org, ocfs2-devel@lists.linux.dev, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-usb@vger.kernel.org, Amir Goldstein , linux-erofs@lists.ozlabs.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH RFC 40/41] erofs: refuse files on pseudo filesystems as backing files Message-ID: Mail-Followup-To: Christian Brauner , linux-fsdevel@vger.kernel.org, Jann Horn , Chris Mason , Josef Bacik , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Alexander Viro , Jan Kara , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, driver-core@lists.linux.dev, linux-mm@kvack.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, apparmor@lists.ubuntu.com, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, fuse-devel@lists.linux.dev, linux-efi@vger.kernel.org, xen-devel@lists.xenproject.org, ocfs2-devel@lists.linux.dev, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-usb@vger.kernel.org, Amir Goldstein , linux-erofs@lists.ozlabs.org, linux-kselftest@vger.kernel.org References: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> <20261110-work-loop-pseudo-v1-40-4c998976c6c7@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20261110-work-loop-pseudo-v1-40-4c998976c6c7@kernel.org> On Tue, Nov 10, 2026 at 10:14:56AM +0100, Christian Brauner wrote: > File-backed mounts take any regular file as the image and the same goes > for the extra devices of such a mount. erofs reads them with the > credentials of the mounter so this doesn't hand out anything the mounter > couldn't read anyway. But files on pseudo filesystems aren't images. > Refuse them just like loop does. > > Signed-off-by: Christian Brauner (Amutable) Reviewed-by: Gao Xiang Thanks, Gao Xiang