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 4544719C546; Wed, 18 Mar 2026 18:44:30 +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=1773859470; cv=none; b=jCdArtm5WJsw8eq1MPAXG8GZUpvQ6yTOAUXlXEg1LxO9Z9WYo2jw7fh2k2yi5xRKhseXlmMmAclTSQj54nYsWxfvDyVDM0M0iMdFvBYkuxDngh2VZGPRp2h8aTefCjdi5R0m0Vr7qHwNJ+neqiBpe3SDST/uSjL3YKVEVfh2Gic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773859470; c=relaxed/simple; bh=d/5YsHV2PKUMXB+uIpWwal1wS+f2kTUASoCVQoo16Z0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Hu0se/3txVMuydj8/dCGKQ12Zl0zbax5GHqAIIs5Ig35dZAmDAzHqdWUSyR7eDYEkZcbJywtugr70JVPj6VY/ebYl0GPvpSZAMA/SFomNsB3vmzj3txVvQpg1o+9m3pZPLDfgX//JVN8eoa8r2x627BY3hRn2CUn3w1sDkHnNf8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j3K8/cZJ; 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="j3K8/cZJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB6B2C19421; Wed, 18 Mar 2026 18:44:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773859469; bh=d/5YsHV2PKUMXB+uIpWwal1wS+f2kTUASoCVQoo16Z0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j3K8/cZJTXt42OoEUAWrQ9dRdjGRc+JphRiLohXAXlF++DWo7wMpS7bYaMFc9wyGA BB6rsHFwYrGvtqqNwRqZXsxPTczi/ykfFDQGp/UlIYSGiQm6mHfLgbHmYS/7uQEzmS aKfOfF2QJuWPV8yoZNwg+smEEI6NxCRWav98fLolXNZlEo309jyrQtOb+egsH2CG++ rmFigwmMRMXVsaJLZeWob0ylu7jRTDuqoOfZJDpSffCITFm3D1pqT1a4CLAX0a5TVs l6Wi98vuLKOqtkfBB3/ZHGe1eO2SDtLO/F+bf9vNNy0C7bkIJWskH1Xw1uIY2jXg6N OEnPPimgbRJLQ== 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 4/7] selinux: Convert from sb_mount to granular mount hooks Date: Wed, 18 Mar 2026 11:43:57 -0700 Message-ID: <20260318184400.3502908-5-song@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260318184400.3502908-1-song@kernel.org> References: <20260318184400.3502908-1-song@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@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. 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 d8224ea113d1..415b5541ab9e 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2778,19 +2778,37 @@ 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, @@ -7449,7 +7467,12 @@ 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