On Wed, Mar 18, 2026 at 2:44 PM Song Liu <[email protected]> wrote:
>
> Now that all LSMs have been converted to granular mount hooks,
> remove the old hooks:
>
> - security_sb_mount(): removed from lsm_hook_defs.h, security.h,
>   security.c, and its call in path_mount().
> - security_move_mount(): removed and replaced by security_mount_move()
>   in do_move_mount(). All LSMs now use mount_move exclusively.
>
> Code generated with the assistance of Claude, reviewed by human.
>
> Signed-off-by: Song Liu <[email protected]>

Reviewed-by: Stephen Smalley <[email protected]>
Tested-by: Stephen Smalley <[email protected] # for selinux only

> ---
>  fs/namespace.c                |  6 +-----
>  include/linux/lsm_hook_defs.h |  4 ----
>  include/linux/security.h      | 16 ---------------
>  kernel/bpf/bpf_lsm.c          |  2 --
>  security/apparmor/lsm.c       |  1 -
>  security/landlock/fs.c        |  1 -
>  security/security.c           | 38 -----------------------------------
>  security/selinux/hooks.c      |  2 --
>  8 files changed, 1 insertion(+), 69 deletions(-)
>
> diff --git a/fs/namespace.c b/fs/namespace.c
> index de33070e514a..ba5baccdde67 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -4108,7 +4108,6 @@ int path_mount(const char *dev_name, const struct path 
> *path,
>                 const char *type_page, unsigned long flags, void *data_page)
>  {
>         unsigned int mnt_flags = 0, sb_flags;
> -       int ret;
>
>         /* Discard magic */
>         if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
> @@ -4121,9 +4120,6 @@ int path_mount(const char *dev_name, const struct path 
> *path,
>         if (flags & MS_NOUSER)
>                 return -EINVAL;
>
> -       ret = security_sb_mount(dev_name, path, type_page, flags, data_page);
> -       if (ret)
> -               return ret;
>         if (!may_mount())
>                 return -EPERM;
>         if (flags & SB_MANDLOCK)
> @@ -4538,7 +4534,7 @@ static inline int vfs_move_mount(const struct path 
> *from_path,
>  {
>         int ret;
>
> -       ret = security_move_mount(from_path, to_path);
> +       ret = security_mount_move(from_path, to_path);
>         if (ret)
>                 return ret;
>
> diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
> index 6bb67059fb43..95537574c40b 100644
> --- a/include/linux/lsm_hook_defs.h
> +++ b/include/linux/lsm_hook_defs.h
> @@ -69,8 +69,6 @@ LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void 
> *mnt_opts)
>  LSM_HOOK(int, 0, sb_kern_mount, const struct super_block *sb)
>  LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
>  LSM_HOOK(int, 0, sb_statfs, struct dentry *dentry)
> -LSM_HOOK(int, 0, sb_mount, const char *dev_name, const struct path *path,
> -        const char *type, unsigned long flags, void *data)
>  LSM_HOOK(int, 0, sb_umount, struct vfsmount *mnt, int flags)
>  LSM_HOOK(int, 0, sb_pivotroot, const struct path *old_path,
>          const struct path *new_path)
> @@ -79,8 +77,6 @@ LSM_HOOK(int, 0, sb_set_mnt_opts, struct super_block *sb, 
> void *mnt_opts,
>  LSM_HOOK(int, 0, sb_clone_mnt_opts, const struct super_block *oldsb,
>          struct super_block *newsb, unsigned long kern_flags,
>          unsigned long *set_kern_flags)
> -LSM_HOOK(int, 0, move_mount, const struct path *from_path,
> -        const struct path *to_path)
>  LSM_HOOK(int, 0, mount_bind, const struct path *from, const struct path *to,
>          bool recurse)
>  LSM_HOOK(int, 0, mount_new, struct fs_context *fc, const struct path *mp,
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 6e31de9b3d68..3610a49304c6 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -372,8 +372,6 @@ int security_sb_remount(struct super_block *sb, void 
> *mnt_opts);
>  int security_sb_kern_mount(const struct super_block *sb);
>  int security_sb_show_options(struct seq_file *m, struct super_block *sb);
>  int security_sb_statfs(struct dentry *dentry);
> -int security_sb_mount(const char *dev_name, const struct path *path,
> -                     const char *type, unsigned long flags, void *data);
>  int security_sb_umount(struct vfsmount *mnt, int flags);
>  int security_sb_pivotroot(const struct path *old_path, const struct path 
> *new_path);
>  int security_sb_set_mnt_opts(struct super_block *sb,
> @@ -384,7 +382,6 @@ int security_sb_clone_mnt_opts(const struct super_block 
> *oldsb,
>                                 struct super_block *newsb,
>                                 unsigned long kern_flags,
>                                 unsigned long *set_kern_flags);
> -int security_move_mount(const struct path *from_path, const struct path 
> *to_path);
>  int security_mount_bind(const struct path *from, const struct path *to,
>                         bool recurse);
>  int security_mount_new(struct fs_context *fc, const struct path *mp,
> @@ -818,13 +815,6 @@ static inline int security_sb_statfs(struct dentry 
> *dentry)
>         return 0;
>  }
>
> -static inline int security_sb_mount(const char *dev_name, const struct path 
> *path,
> -                                   const char *type, unsigned long flags,
> -                                   void *data)
> -{
> -       return 0;
> -}
> -
>  static inline int security_sb_umount(struct vfsmount *mnt, int flags)
>  {
>         return 0;
> @@ -852,12 +842,6 @@ static inline int security_sb_clone_mnt_opts(const 
> struct super_block *oldsb,
>         return 0;
>  }
>
> -static inline int security_move_mount(const struct path *from_path,
> -                                     const struct path *to_path)
> -{
> -       return 0;
> -}
> -
>  static inline int security_mount_bind(const struct path *from,
>                                       const struct path *to, bool recurse)
>  {
> diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
> index 65235d70ee23..3e61c54f9b48 100644
> --- a/kernel/bpf/bpf_lsm.c
> +++ b/kernel/bpf/bpf_lsm.c
> @@ -350,7 +350,6 @@ BTF_ID(func, bpf_lsm_release_secctx)
>  BTF_ID(func, bpf_lsm_sb_alloc_security)
>  BTF_ID(func, bpf_lsm_sb_eat_lsm_opts)
>  BTF_ID(func, bpf_lsm_sb_kern_mount)
> -BTF_ID(func, bpf_lsm_sb_mount)
>  BTF_ID(func, bpf_lsm_sb_remount)
>  BTF_ID(func, bpf_lsm_sb_set_mnt_opts)
>  BTF_ID(func, bpf_lsm_sb_show_options)
> @@ -383,7 +382,6 @@ BTF_ID(func, bpf_lsm_task_prctl)
>  BTF_ID(func, bpf_lsm_task_setscheduler)
>  BTF_ID(func, bpf_lsm_task_to_inode)
>  BTF_ID(func, bpf_lsm_userns_create)
> -BTF_ID(func, bpf_lsm_move_mount)
>  BTF_ID(func, bpf_lsm_mount_bind)
>  BTF_ID(func, bpf_lsm_mount_new)
>  BTF_ID(func, bpf_lsm_mount_remount)
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index 7fe774535992..13a8049b1b59 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1713,7 +1713,6 @@ static struct security_hook_list apparmor_hooks[] 
> __ro_after_init = {
>         LSM_HOOK_INIT(capget, apparmor_capget),
>         LSM_HOOK_INIT(capable, apparmor_capable),
>
> -       LSM_HOOK_INIT(move_mount, apparmor_move_mount),
>         LSM_HOOK_INIT(mount_bind, apparmor_mount_bind),
>         LSM_HOOK_INIT(mount_new, apparmor_mount_new),
>         LSM_HOOK_INIT(mount_remount, apparmor_mount_remount),
> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
> index 6e810550efcb..5f723a70baa4 100644
> --- a/security/landlock/fs.c
> +++ b/security/landlock/fs.c
> @@ -1857,7 +1857,6 @@ static struct security_hook_list landlock_hooks[] 
> __ro_after_init = {
>         LSM_HOOK_INIT(mount_reconfigure, hook_mount_reconfigure),
>         LSM_HOOK_INIT(mount_change_type, hook_mount_change_type),
>         LSM_HOOK_INIT(mount_move, hook_move_mount),
> -       LSM_HOOK_INIT(move_mount, hook_move_mount),
>         LSM_HOOK_INIT(sb_umount, hook_sb_umount),
>         LSM_HOOK_INIT(sb_remount, hook_sb_remount),
>         LSM_HOOK_INIT(sb_pivotroot, hook_sb_pivotroot),
> diff --git a/security/security.c b/security/security.c
> index 356ef228d5de..af95868af34d 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1039,29 +1039,6 @@ int security_sb_statfs(struct dentry *dentry)
>         return call_int_hook(sb_statfs, dentry);
>  }
>
> -/**
> - * security_sb_mount() - Check permission for mounting a filesystem
> - * @dev_name: filesystem backing device
> - * @path: mount point
> - * @type: filesystem type
> - * @flags: mount flags
> - * @data: filesystem specific data
> - *
> - * Check permission before an object specified by @dev_name is mounted on the
> - * mount point named by @nd.  For an ordinary mount, @dev_name identifies a
> - * device if the file system type requires a device.  For a remount
> - * (@flags & MS_REMOUNT), @dev_name is irrelevant.  For a loopback/bind mount
> - * (@flags & MS_BIND), @dev_name identifies the        pathname of the 
> object being
> - * mounted.
> - *
> - * Return: Returns 0 if permission is granted.
> - */
> -int security_sb_mount(const char *dev_name, const struct path *path,
> -                     const char *type, unsigned long flags, void *data)
> -{
> -       return call_int_hook(sb_mount, dev_name, path, type, flags, data);
> -}
> -
>  /**
>   * security_sb_umount() - Check permission for unmounting a filesystem
>   * @mnt: mounted filesystem
> @@ -1141,21 +1118,6 @@ int security_sb_clone_mnt_opts(const struct 
> super_block *oldsb,
>  }
>  EXPORT_SYMBOL(security_sb_clone_mnt_opts);
>
> -/**
> - * security_move_mount() - Check permissions for moving a mount
> - * @from_path: source mount point
> - * @to_path: destination mount point
> - *
> - * Check permission before a mount is moved.
> - *
> - * Return: Returns 0 if permission is granted.
> - */
> -int security_move_mount(const struct path *from_path,
> -                       const struct path *to_path)
> -{
> -       return call_int_hook(move_mount, from_path, to_path);
> -}
> -
>  /**
>   * security_mount_bind() - Check permissions for a bind mount
>   * @from: source path
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 415b5541ab9e..446e9e242134 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -7477,8 +7477,6 @@ static struct security_hook_list selinux_hooks[] 
> __ro_after_init = {
>         LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
>         LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
>
> -       LSM_HOOK_INIT(move_mount, selinux_move_mount),
> -
>         LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
>         LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
>
> --
> 2.52.0
>

Reply via email to