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=1794661664; b=YWYgIi74u0hykKmeds5qSz1i524gPz1VKpU3P/KlUv4nbWN+lIytC5UowuuRPUHj1Th9 Fb5j6U3zc/uwTMAwpnCBMQMIxmV66kNLPxqQ2WmNiPCY1qQ8YkXmGqDmu9MPDKvNzrT++ /DGAWO0xcxlGX0oSVyhg1XX6MYavjcfVO+mltcRe+o3Q52C7bD75L+jfoAYwxtWS2EJA7 pbkDbgZz4zmhPJYx/rafKxTSEAFmTvmuHCZt8WEdZebLKTiHMX2U0B7lN1Uo3ITZmEaj1 zsRYw2on0e+6zxJc5csANSFw3PxlL5tIbWEPnuoGoITvS34Am4t8qqZm3BcubxC330A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794661664; 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=PsEZAEo2EWjwlrQyS8FDrkYLrSxc4EoXaQ3VAa3T0to=; b=45rYBaYtD2uxQgwKEHraqMJM5n3rkpo/AYurQ3ofNYjR2yeBo99zLfHokLCR8AkbvHpJ pt9ptPEvPd2SvTR3wfutSEDIG+llIXl5fUz543XNi1MW7Y4Ey0n6oufhr2AujRw75KshF pzCQ9bi11FOxk4Ec5Q9iXTs1QwlLgcsNUzEcfMbQn4QjUOg9+C5gAT1v9pzYTHbebAUT9 pb+z2B8PeaTcQ4lcT15HIm30ZIfjdJlj5q5+S8fJKVbj+RgPM8IWUbh3bN9FqIurXwSM8 yZeIiBqqCLfDEt10A1b9N7bZyZFuTsEp/byLoqWBg5W1OHrfiCwPLA4XnDY0OsMCirg== 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=RP6bdqxg; 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 20CDB606FB2D; Sat, 14 Nov 2026 13:07:43 +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=RP6bdqxg Received: by smtp.kernel.org (Postfix) with ESMTPSA id 254A51F000C4; Sat, 14 Nov 2026 13:07:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794661663; bh=PsEZAEo2EWjwlrQyS8FDrkYLrSxc4EoXaQ3VAa3T0to=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=RP6bdqxgYdTOvKQFb6NUJlAnzP0iuFZn14JV3dopj4eOhvt4mal1MYZtl7BQYCoxt w45XbT2grNM6Qg55/tsCLUdM0CQBOxLR2Kunja7yy54lP9Qfg63cbpj/uCek58LMdr 2g0icThdvpsN4HTsfTKz9VeiMePWjWf1Q1K5NnEjU8lTRxQrEHOb8z5qeiSteKne2v cZsD/rPxnGg04mAtEBHiWHv5l/XXKkWr1ku1sBIHTZe1CFwHTqP1ghScoLp+fr2OPo fJrxBzLLgHTvheGhtWCqgnNRz1198UueTs5pHbgLcHIkedb4JvrikevLf2qm5DDpBH /871dihUSqoKg== From: Christian Brauner Date: Sat, 14 Nov 2026 14:01:59 +0100 Subject: [PATCH RFC v2 18/42] selinux: use fc_init_pseudo() for selinuxfs 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: <20261114-work-loop-pseudo-v2-18-98639a2286fb@kernel.org> References: <20261114-work-loop-pseudo-v2-0-98639a2286fb@kernel.org> In-Reply-To: <20261114-work-loop-pseudo-v2-0-98639a2286fb@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)" , Alexander Mikhalitsyn X-Mailer: b4 0.17-dev-ce4c1 X-Developer-Signature: v=1; a=openpgp-sha256; l=1689; i=brauner@kernel.org; h=from:subject:message-id; bh=Eg4JynB39S+cJriPMxPoEFKswaAikvmz7VyAKkVX+DM=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWT9iKlyMVy9yP1TKKNxrIjSmW/cGdIrJik/frn0dv3to /8K4+ukO0pZGMS4GGTFFFkc2k3C5ZbzVGw2ytSAmcPKBDKEgYtTACYSMIHhv2uEhSiX6eXHduxb hf4+qrT5tnTptBUl2zO0TXL7X/736WFkWNSWEJ/+ZOJcg73v3vA+s01c+03lUdAuJu+uVeeshCM ymAA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Initialize selinuxfs as a pseudo filesystem. This raises SB_I_PSEUDO and SB_I_NOEXEC. selinuxfs never holds executables. SB_I_NOEXEC also refuses PROT_EXEC mappings but the status and policy files are only ever mapped for reading. But selinuxfs needs device nodes. The kernel replaces file descriptors with /sys/fs/selinux/null on exec via dentry_open() which doesn't care about SB_I_NODEV. Android init however opens /sys/fs/selinux/null by path as /dev/null doesn't exist yet at that point. So clear SB_I_NODEV again in sel_fill_super(). Reviewed-by: Alexander Mikhalitsyn Signed-off-by: Christian Brauner (Amutable) --- security/selinux/selinuxfs.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 310e19efff1d0..d7ae853b6d685 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -1852,6 +1853,9 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc) /* last one */ {"", NULL, 0} }; + /* Android init opens the null device below by path. */ + sb->s_iflags &= ~SB_I_NODEV; + ret = selinux_fs_info_create(sb); if (ret) goto err; @@ -1955,6 +1959,7 @@ static const struct fs_context_operations sel_context_ops = { static int sel_init_fs_context(struct fs_context *fc) { + fc_init_pseudo(fc); fc->ops = &sel_context_ops; return 0; } -- 2.53.0