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 <[email protected]> --- 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
