From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794302411; b=gRhd+L/0kpcOtABgnt2TM6dP8AhGqQt+NmKwlnYcfG0BG+UrJK6c2Szsiklfl8e5cEE+ FlFC2bM9amI5z5OxNBtnCx0xnObJPS8JUJHdafdqMR1gj8YPNu8pq8a2HPrQ0HanQDYC3 yFJQMDUD4SrVlza8y9q0u9y9aJGI6EU9hitvxtm+jCWI0/eWjuukVhT62AlsKuPhTkPNA dbyqVT4BnHJygq05KBWHkz2FjG0fpO5NIX5KAuadlzmlQ8dmss3rs/BQyiAzxWcoLZ6j/ zLCd+iriti4i59EPgAxN5kjZZkwzaO9J0KZQ/GsEb1sFtZuOb1pdezlsopCiDYbQ2TQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794302411; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=wvcrRKkVitwBIHc8bsc86Ap1TkghVmPhKT6D7YPBbwY=; b=micBf6BzPCTfrdTIuI5m5QfLqV2O7AkAdg5WO2sSBZTTqyYKuoUxb1uEJHyGbXX3vzql K3YgEFs1Dq25y/qAkMtggPxy+RhOodLntj2SuVQOVNDsUccUvCJ78F877TsRDpq5Y46Ev wBCsmQ8ZJ0KO2JMg/s6HMWSMSLPS6s8s1xfLbv6EKWFTI1QSuG6wzO9wfYiXsS+GBDP91 WeiC/Hsf+0Z4WmYgE2B/uVDEjTSsNCjD20ucH3+1DhlovXQDVjB3bFT91WMCdqYqM1OF9 VwW88kS2UIKa/LA0fueHlIs+nTLnFhsWNJLk2parNT8bZKY2wTmNc49TnBEsvAitcWQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lugfFYds; 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 4F1D6607C095; Tue, 10 Nov 2026 09:20:11 +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=lugfFYds Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61E501F008A1; Tue, 10 Nov 2026 09:20:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794302410; bh=wvcrRKkVitwBIHc8bsc86Ap1TkghVmPhKT6D7YPBbwY=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=lugfFYdsp+5acpRZ62DrLNSRpPTqwD6ALObkR4htZDZ7jJ4CwxnL+J31LlzQBLdHg S3Q6wKQ8rLKVDvOjaO/7i9LdpOAAGQkJVKTTZnDkbfMZ0mXM3yVItsw5AH/x4JgMCS r17kh6jTusP0FcEnEBzFzqzJtQ746vPtMKO+E1iLTHLZ7PgzOBIB9SrMppxD4aMf6g ++c6vcWP0wgZ4rHVjr+6Av5KOdeAceVogEGD1LonYdJsm5MlecXYdFkPg3OEFOR0DA l4vCIncvJpwPXykOZGsC4m66wbdnnjiMUoL8mSoluVAzhYGK1Oc9EGsTAAgpOcHIVj fpmwuommLUy7A== From: Christian Brauner Date: Tue, 10 Nov 2026 10:14:53 +0100 Subject: [PATCH RFC 37/41] target: fileio: refuse files on pseudo filesystems as backing files 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-Transfer-Encoding: 7bit Message-Id: <20261110-work-loop-pseudo-v1-37-4c998976c6c7@kernel.org> References: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> In-Reply-To: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: 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, "Christian Brauner (Amutable)" X-Mailer: b4 0.17-dev-ce4c1 X-Developer-Signature: v=1; a=openpgp-sha256; l=995; i=brauner@kernel.org; h=from:subject:message-id; bh=BDYGZBkzpJOf0luK2Iqx3jSxHLpIeW6e4aOnDtryI1I=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWR9erDf6mtMEqNwmyJbTeSGX/PXP05KecQy9ejD6kOb9 /3cf9Hkd0cpC4MYF4OsmCKLQ7tJuNxynorNRpkaMHNYmUCGMHBxCsBETl9m+F99+X7Ky605zSv7 GErvWk1zaPix/Pxk04Q9+p1/0oTy/pgx/JXbprm34uPtr4v2Ll0y0cL+SOu1/dVOakafmv0qqj/ fj+YCAA== X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 fd_dev_name can name any file including files on procfs or sysfs. The initiator then gets to read and write kernel interfaces through the LUN with kernel credentials. Refuse files on pseudo filesystems just like loop does. Signed-off-by: Christian Brauner (Amutable) --- drivers/target/target_core_file.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index a5391e57e9aa..7a3cf63dc979 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -152,6 +152,13 @@ static int fd_configure_device(struct se_device *dev) goto fail; } + if (file_is_pseudo(file)) { + pr_err("FILEIO: %s is on a pseudo filesystem\n", + fd_dev->fd_dev_name); + ret = -EINVAL; + goto fail; + } + /* * If using a block backend with this struct file, we extract * fd_dev->fd_[block,dev]_size from struct block_device. -- 2.53.0