From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8F6F840DFDB; Thu, 30 Apr 2026 00:04:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777507460; cv=none; b=JD86DCOuaTDsLX7jBEGhNREEc2XleG3865oCrCBheOj/YxxCR0eT3TqrHiuRrW6NnzcK3jGL0xdNNtIYdhVqmOv1MpZ0NwhZdsneOP0e5d7uOIGstGbuZjUQJY+nbDFU+v4u2v2nQG3ywkidbFS9nm23QzDJ8cVJkbVHssswvXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777507460; c=relaxed/simple; bh=kQpR7f7zhcEaGggR0lMXimoDWOjcXP7AIpA9hGFTcLs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MIKGZguASAl+GiUcLk3WANqtFL/mVI2+lRWKh+cdq71bY29ImV4iWdHu5COYT43rrDg0xfJ7+75ZwtR2MNWrR81MfKu8Y6p+a4ww/HsnHr+1WTfjUnrOWwSrtzdFAJPiNKvBOUWKoCz1fFJDPqx5b32Gm+Wsywt++y+hBFkHgbA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aMJEeuMy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aMJEeuMy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90F5EC2BCB4; Thu, 30 Apr 2026 00:04:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777507460; bh=kQpR7f7zhcEaGggR0lMXimoDWOjcXP7AIpA9hGFTcLs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aMJEeuMyQmkK0E24YJ5YNJaamnd0nRjomlvPFTDJOE/p0776hXqQbY1hQT/nNDyX/ 1ASGk/AXjiRca6utz4AW6bT82koUIgpPmU2n6c0LKiT2v3RJqX6ih/ZCOl7ahFn9Jf iLAHvpiTfkWG6pV5LoJaqqcnn9z0LnJf+fTGm6QXuqL4XEtmX4rF9wrq654f7f2i/A iIxuwQuPrtvZVI12uKEZ0+HylowVn9eBtfrbqB+OUoXUoAyjTLYO3AqiUVHRMJYc5H YH7K1HNr50NFOlWFlT/+9wkw9OjjAkShIRjbwpFr58kXB3HCK1eoezUcktgwydv3CD 6IDB/qAtNdShw== From: Song Liu To: linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, selinux@vger.kernel.org, apparmor@lists.ubuntu.com Cc: paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, john.johansen@canonical.com, stephen.smalley.work@gmail.com, omosnace@redhat.com, mic@digikod.net, gnoack@google.com, takedakn@nttdata.co.jp, penguin-kernel@I-love.SAKURA.ne.jp, herton@canonical.com, kernel-team@meta.com, Song Liu Subject: [PATCH v2 4/7] selinux: Convert from sb_mount to granular mount hooks Date: Wed, 29 Apr 2026 17:03:12 -0700 Message-ID: <20260430000315.918964-5-song@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260430000315.918964-1-song@kernel.org> References: <20260430000315.918964-1-song@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Replace selinux_mount() with granular mount hooks, preserving the same permission checks: - mount_bind, mount_new, mount_change_type: FILE__MOUNTON - mount_remount, mount_reconfigure: FILESYSTEM__REMOUNT - mount_move: FILE__MOUNTON (reuses selinux_move_mount) The flags and data parameters are unused by SELinux. Code generated with the assistance of Claude, reviewed by human. Reviewed-by: Stephen Smalley Tested-by: Stephen Smalley Signed-off-by: Song Liu --- security/selinux/hooks.c | 47 ++++++++++++++++++++++++++++++---------- 1 file changed, 35 insertions(+), 12 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 97801966bf32..f0d9712356cf 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2802,19 +2802,37 @@ static int selinux_sb_statfs(struct dentry *dentry) return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); } -static int selinux_mount(const char *dev_name, - const struct path *path, - const char *type, - unsigned long flags, - void *data) +static int selinux_mount_bind(const struct path *from, const struct path *to, + bool recurse) { - const struct cred *cred = current_cred(); + return path_has_perm(current_cred(), to, FILE__MOUNTON); +} - if (flags & MS_REMOUNT) - return superblock_has_perm(cred, path->dentry->d_sb, - FILESYSTEM__REMOUNT, NULL); - else - return path_has_perm(cred, path, FILE__MOUNTON); +static int selinux_mount_new(struct fs_context *fc, const struct path *mp, + int mnt_flags, unsigned long flags, void *data) +{ + return path_has_perm(current_cred(), mp, FILE__MOUNTON); +} + +static int selinux_mount_remount(struct fs_context *fc, const struct path *mp, + int mnt_flags, unsigned long flags, + void *data) +{ + return superblock_has_perm(current_cred(), fc->root->d_sb, + FILESYSTEM__REMOUNT, NULL); +} + +static int selinux_mount_reconfigure(const struct path *mp, + unsigned int mnt_flags, + unsigned long flags) +{ + return superblock_has_perm(current_cred(), mp->dentry->d_sb, + FILESYSTEM__REMOUNT, NULL); +} + +static int selinux_mount_change_type(const struct path *mp, int ms_flags) +{ + return path_has_perm(current_cred(), mp, FILE__MOUNTON); } static int selinux_move_mount(const struct path *from_path, @@ -7562,7 +7580,12 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount), LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options), LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs), - LSM_HOOK_INIT(sb_mount, selinux_mount), + LSM_HOOK_INIT(mount_bind, selinux_mount_bind), + LSM_HOOK_INIT(mount_new, selinux_mount_new), + LSM_HOOK_INIT(mount_remount, selinux_mount_remount), + LSM_HOOK_INIT(mount_reconfigure, selinux_mount_reconfigure), + LSM_HOOK_INIT(mount_change_type, selinux_mount_change_type), + LSM_HOOK_INIT(mount_move, selinux_move_mount), LSM_HOOK_INIT(sb_umount, selinux_umount), LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts), LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts), -- 2.52.0